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POP-RT trial supports whole-pelvis radiotherapy for high-risk prostate cancer
Results from the trial, called POP-RT, were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“A question that has been plaguing the radiation oncology community for the last 3 or 4 decades is, ‘Should the pelvic nodes be treated prophylactically in patients with high-risk prostate cancer?’ ” said Vedang Murthy, MD, of Tata Memorial Centre in Mumbai, India, who presented the POP-RT trial at the meeting.
“A lot of effort has gone into trying to answer this question,” he added.
Unfortunately, the question has remained unanswered, as neither the RTOG 9413 trial nor the French GETUG-01 trial showed clear evidence of benefit.
To gain some insight, Dr. Murthy and colleagues conducted the POP-RT trial (NCT02302105). The study’s final analysis included 222 men with locally advanced prostate cancer who had node-negative disease based on MRI and PSMA PET, but had a high risk for occult pelvic nodal involvement (20% or greater according to the Roach formula). The median nodal risk for the trial population was 37.8%.
The men were randomized to daily image-guided intensity-modulated radiotherapy to the prostate (68 Gy in 25 fractions to the gland and seminal vesicles) or to the whole pelvis (the former plus 50 Gy in 25 fractions to the pelvic nodes as a simultaneous integrated boost, including the bilateral common iliac, internal and external iliac, presacral, and obturator node groups). All patients also received at least 2 years of androgen-deprivation therapy (ADT).
Efficacy and toxicity
At a median follow-up of 68 months, the 5-year rate of biochemical failure–free survival, the trial’s primary endpoint, was superior with whole-pelvis radiotherapy (WPRT), at 95.0%, relative to prostate-only radiotherapy (PORT), at 81.2% (hazard ratio, 0.23; P < .0001), Dr. Murthy reported.
Disease-free survival was better in the WPRT group than in the PORT group (89.5% vs. 77.2%; HR, 0.40; P = .002), and the same was true for distant metastasis–free survival (95.0% vs. 87.9%; HR, 0.35; P = .01).
Overall survival was 92.5% with WPRT and 90.8% with PORT, a nonsignificant difference (P = .83).
At the time of biochemical failure, disease recurred in the regional pelvic nodes (with or without distant metastases) in just 1 patient in the WPRT group, compared with 15 patients in the PORT group. Recurrences at other sites were similar across the groups.
The WPRT group had a significantly higher rate of late genitourinary toxicity (17.7% vs. 7.5%; P = .03) but not late gastrointestinal toxicity (6.5% vs. 3.8%; P = .4).
There were no grade 4 toxicities, and the groups were similar on patient-reported outcomes.
Explaining the results
Several factors may explain why the POP-RT trial was clearly positive for WPRT, whereas the RTOG 9413 and GETUG-01 trials were not, according to Dr. Murthy.
“We had a much higher-risk group,” he elaborated (with 55% of patients having a nodal risk exceeding 35%), and PSMA PET was used in the workup in the large majority of patients, improving diagnostic sensitivity.
In delivering radiation, “we made sure to include the common iliac nodes and to go up to L4 and L5 and the common iliac junction,” Dr. Murthy further noted.
Also, the POP-RT trial had a higher prostate dose (biological equivalent dose of 129.6 Gy), used image-guided intensity-modulated radiotherapy, and administered ADT for much longer than the other trial (2 years vs. 4-8 months).
“Prophylactic radiotherapy in this trial improved biochemical failure–free survival and disease-free survival in high-risk prostate cancer patients. The improvement in outcomes was seen in spite of giving long-term ADT and in spite of doing dose escalation,” Dr. Murthy summarized. “There is no overall survival difference as of yet, but that remains to be seen.”
“Based on these results, it would be fair to say that whole-pelvis radiotherapy should be considered for these patients with high-risk and very-high-risk prostate cancer,” he concluded.
Practice-changing findings
“Overall, I’m very impressed with this study,” commented Colleen A. Lawton, MD, of Medical College of Wisconsin, Milwaukee. “The primary endpoint of biochemical failure–free survival is not a great one, but fortunately, the distant metastasis-free survival, a secondary endpoint, was statistically improved also.”
The POP-RT results are not surprising given other lines of evidence, she noted. For example, early results of a trial among postprostatectomy patients (RTOG 0534) suggest a benefit of pelvic lymph node radiation, and findings from studies in other adenocarcinomas, such as breast and rectal, show that treating the lymph nodes improves outcomes.
“I think the data are practice changing. … mostly because there is so much retrospective data suggesting a benefit from lymph node radiotherapy for prostate cancer, especially with adequate doses, but this is the first prospective randomized trial to use proper dosing to the primary and lymph nodes, and adequate ADT,” Dr. Lawton said. “The use of PSMA PET is also important from a selection perspective in identifying patients more likely to have microscopic versus gross lymph node involvement and in follow-up to identify which patients fail in the lymph nodes.”
“I agree with the authors’ conclusions and would definitely recommend lymph node radiotherapy for these high- and very-high-risk patients in addition to the ADT,” she concluded. “The dose to the lymph nodes at 50 Gy in 25 fractions is a bit higher than has been used in all of the RTOG trials (45 Gy in 25 fractions), and I do believe that adequate doses are critical in seeing a benefit to treatment.”
The POP-RT trial was funded by Tata Memorial Centre, the Uro-Oncology Disease Management Group, and the Terry Fox Foundation. Dr. Murthy disclosed no conflicts of interest. Dr. Lawton disclosed that she was a coauthor of the RTOG 9413 trial.
SOURCE: Murthy V et al. ESTRO 2020, Abstract OC-0613.
Results from the trial, called POP-RT, were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“A question that has been plaguing the radiation oncology community for the last 3 or 4 decades is, ‘Should the pelvic nodes be treated prophylactically in patients with high-risk prostate cancer?’ ” said Vedang Murthy, MD, of Tata Memorial Centre in Mumbai, India, who presented the POP-RT trial at the meeting.
“A lot of effort has gone into trying to answer this question,” he added.
Unfortunately, the question has remained unanswered, as neither the RTOG 9413 trial nor the French GETUG-01 trial showed clear evidence of benefit.
To gain some insight, Dr. Murthy and colleagues conducted the POP-RT trial (NCT02302105). The study’s final analysis included 222 men with locally advanced prostate cancer who had node-negative disease based on MRI and PSMA PET, but had a high risk for occult pelvic nodal involvement (20% or greater according to the Roach formula). The median nodal risk for the trial population was 37.8%.
The men were randomized to daily image-guided intensity-modulated radiotherapy to the prostate (68 Gy in 25 fractions to the gland and seminal vesicles) or to the whole pelvis (the former plus 50 Gy in 25 fractions to the pelvic nodes as a simultaneous integrated boost, including the bilateral common iliac, internal and external iliac, presacral, and obturator node groups). All patients also received at least 2 years of androgen-deprivation therapy (ADT).
Efficacy and toxicity
At a median follow-up of 68 months, the 5-year rate of biochemical failure–free survival, the trial’s primary endpoint, was superior with whole-pelvis radiotherapy (WPRT), at 95.0%, relative to prostate-only radiotherapy (PORT), at 81.2% (hazard ratio, 0.23; P < .0001), Dr. Murthy reported.
Disease-free survival was better in the WPRT group than in the PORT group (89.5% vs. 77.2%; HR, 0.40; P = .002), and the same was true for distant metastasis–free survival (95.0% vs. 87.9%; HR, 0.35; P = .01).
Overall survival was 92.5% with WPRT and 90.8% with PORT, a nonsignificant difference (P = .83).
At the time of biochemical failure, disease recurred in the regional pelvic nodes (with or without distant metastases) in just 1 patient in the WPRT group, compared with 15 patients in the PORT group. Recurrences at other sites were similar across the groups.
The WPRT group had a significantly higher rate of late genitourinary toxicity (17.7% vs. 7.5%; P = .03) but not late gastrointestinal toxicity (6.5% vs. 3.8%; P = .4).
There were no grade 4 toxicities, and the groups were similar on patient-reported outcomes.
Explaining the results
Several factors may explain why the POP-RT trial was clearly positive for WPRT, whereas the RTOG 9413 and GETUG-01 trials were not, according to Dr. Murthy.
“We had a much higher-risk group,” he elaborated (with 55% of patients having a nodal risk exceeding 35%), and PSMA PET was used in the workup in the large majority of patients, improving diagnostic sensitivity.
In delivering radiation, “we made sure to include the common iliac nodes and to go up to L4 and L5 and the common iliac junction,” Dr. Murthy further noted.
Also, the POP-RT trial had a higher prostate dose (biological equivalent dose of 129.6 Gy), used image-guided intensity-modulated radiotherapy, and administered ADT for much longer than the other trial (2 years vs. 4-8 months).
“Prophylactic radiotherapy in this trial improved biochemical failure–free survival and disease-free survival in high-risk prostate cancer patients. The improvement in outcomes was seen in spite of giving long-term ADT and in spite of doing dose escalation,” Dr. Murthy summarized. “There is no overall survival difference as of yet, but that remains to be seen.”
“Based on these results, it would be fair to say that whole-pelvis radiotherapy should be considered for these patients with high-risk and very-high-risk prostate cancer,” he concluded.
Practice-changing findings
“Overall, I’m very impressed with this study,” commented Colleen A. Lawton, MD, of Medical College of Wisconsin, Milwaukee. “The primary endpoint of biochemical failure–free survival is not a great one, but fortunately, the distant metastasis-free survival, a secondary endpoint, was statistically improved also.”
The POP-RT results are not surprising given other lines of evidence, she noted. For example, early results of a trial among postprostatectomy patients (RTOG 0534) suggest a benefit of pelvic lymph node radiation, and findings from studies in other adenocarcinomas, such as breast and rectal, show that treating the lymph nodes improves outcomes.
“I think the data are practice changing. … mostly because there is so much retrospective data suggesting a benefit from lymph node radiotherapy for prostate cancer, especially with adequate doses, but this is the first prospective randomized trial to use proper dosing to the primary and lymph nodes, and adequate ADT,” Dr. Lawton said. “The use of PSMA PET is also important from a selection perspective in identifying patients more likely to have microscopic versus gross lymph node involvement and in follow-up to identify which patients fail in the lymph nodes.”
“I agree with the authors’ conclusions and would definitely recommend lymph node radiotherapy for these high- and very-high-risk patients in addition to the ADT,” she concluded. “The dose to the lymph nodes at 50 Gy in 25 fractions is a bit higher than has been used in all of the RTOG trials (45 Gy in 25 fractions), and I do believe that adequate doses are critical in seeing a benefit to treatment.”
The POP-RT trial was funded by Tata Memorial Centre, the Uro-Oncology Disease Management Group, and the Terry Fox Foundation. Dr. Murthy disclosed no conflicts of interest. Dr. Lawton disclosed that she was a coauthor of the RTOG 9413 trial.
SOURCE: Murthy V et al. ESTRO 2020, Abstract OC-0613.
Results from the trial, called POP-RT, were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“A question that has been plaguing the radiation oncology community for the last 3 or 4 decades is, ‘Should the pelvic nodes be treated prophylactically in patients with high-risk prostate cancer?’ ” said Vedang Murthy, MD, of Tata Memorial Centre in Mumbai, India, who presented the POP-RT trial at the meeting.
“A lot of effort has gone into trying to answer this question,” he added.
Unfortunately, the question has remained unanswered, as neither the RTOG 9413 trial nor the French GETUG-01 trial showed clear evidence of benefit.
To gain some insight, Dr. Murthy and colleagues conducted the POP-RT trial (NCT02302105). The study’s final analysis included 222 men with locally advanced prostate cancer who had node-negative disease based on MRI and PSMA PET, but had a high risk for occult pelvic nodal involvement (20% or greater according to the Roach formula). The median nodal risk for the trial population was 37.8%.
The men were randomized to daily image-guided intensity-modulated radiotherapy to the prostate (68 Gy in 25 fractions to the gland and seminal vesicles) or to the whole pelvis (the former plus 50 Gy in 25 fractions to the pelvic nodes as a simultaneous integrated boost, including the bilateral common iliac, internal and external iliac, presacral, and obturator node groups). All patients also received at least 2 years of androgen-deprivation therapy (ADT).
Efficacy and toxicity
At a median follow-up of 68 months, the 5-year rate of biochemical failure–free survival, the trial’s primary endpoint, was superior with whole-pelvis radiotherapy (WPRT), at 95.0%, relative to prostate-only radiotherapy (PORT), at 81.2% (hazard ratio, 0.23; P < .0001), Dr. Murthy reported.
Disease-free survival was better in the WPRT group than in the PORT group (89.5% vs. 77.2%; HR, 0.40; P = .002), and the same was true for distant metastasis–free survival (95.0% vs. 87.9%; HR, 0.35; P = .01).
Overall survival was 92.5% with WPRT and 90.8% with PORT, a nonsignificant difference (P = .83).
At the time of biochemical failure, disease recurred in the regional pelvic nodes (with or without distant metastases) in just 1 patient in the WPRT group, compared with 15 patients in the PORT group. Recurrences at other sites were similar across the groups.
The WPRT group had a significantly higher rate of late genitourinary toxicity (17.7% vs. 7.5%; P = .03) but not late gastrointestinal toxicity (6.5% vs. 3.8%; P = .4).
There were no grade 4 toxicities, and the groups were similar on patient-reported outcomes.
Explaining the results
Several factors may explain why the POP-RT trial was clearly positive for WPRT, whereas the RTOG 9413 and GETUG-01 trials were not, according to Dr. Murthy.
“We had a much higher-risk group,” he elaborated (with 55% of patients having a nodal risk exceeding 35%), and PSMA PET was used in the workup in the large majority of patients, improving diagnostic sensitivity.
In delivering radiation, “we made sure to include the common iliac nodes and to go up to L4 and L5 and the common iliac junction,” Dr. Murthy further noted.
Also, the POP-RT trial had a higher prostate dose (biological equivalent dose of 129.6 Gy), used image-guided intensity-modulated radiotherapy, and administered ADT for much longer than the other trial (2 years vs. 4-8 months).
“Prophylactic radiotherapy in this trial improved biochemical failure–free survival and disease-free survival in high-risk prostate cancer patients. The improvement in outcomes was seen in spite of giving long-term ADT and in spite of doing dose escalation,” Dr. Murthy summarized. “There is no overall survival difference as of yet, but that remains to be seen.”
“Based on these results, it would be fair to say that whole-pelvis radiotherapy should be considered for these patients with high-risk and very-high-risk prostate cancer,” he concluded.
Practice-changing findings
“Overall, I’m very impressed with this study,” commented Colleen A. Lawton, MD, of Medical College of Wisconsin, Milwaukee. “The primary endpoint of biochemical failure–free survival is not a great one, but fortunately, the distant metastasis-free survival, a secondary endpoint, was statistically improved also.”
The POP-RT results are not surprising given other lines of evidence, she noted. For example, early results of a trial among postprostatectomy patients (RTOG 0534) suggest a benefit of pelvic lymph node radiation, and findings from studies in other adenocarcinomas, such as breast and rectal, show that treating the lymph nodes improves outcomes.
“I think the data are practice changing. … mostly because there is so much retrospective data suggesting a benefit from lymph node radiotherapy for prostate cancer, especially with adequate doses, but this is the first prospective randomized trial to use proper dosing to the primary and lymph nodes, and adequate ADT,” Dr. Lawton said. “The use of PSMA PET is also important from a selection perspective in identifying patients more likely to have microscopic versus gross lymph node involvement and in follow-up to identify which patients fail in the lymph nodes.”
“I agree with the authors’ conclusions and would definitely recommend lymph node radiotherapy for these high- and very-high-risk patients in addition to the ADT,” she concluded. “The dose to the lymph nodes at 50 Gy in 25 fractions is a bit higher than has been used in all of the RTOG trials (45 Gy in 25 fractions), and I do believe that adequate doses are critical in seeing a benefit to treatment.”
The POP-RT trial was funded by Tata Memorial Centre, the Uro-Oncology Disease Management Group, and the Terry Fox Foundation. Dr. Murthy disclosed no conflicts of interest. Dr. Lawton disclosed that she was a coauthor of the RTOG 9413 trial.
SOURCE: Murthy V et al. ESTRO 2020, Abstract OC-0613.
FROM ESTRO 2020
One-week radiotherapy course should be standard for early invasive breast cancer, experts say
The trial was designed to compare the standard regimen (40 Gy in 15 fractions over 3 weeks) with a higher-dose hypofractionated regimen (27 Gy in 5 fractions over 5 days) and a lower-dose hypofractionated regimen (26 Gy in 5 fractions over 5 days) in women who had undergone surgery for early invasive breast cancer.
The 5-year rate of ipsilateral breast tumor relapse was similar with all regimens – 2.1% with the 40-Gy regimen, 1.7% with the 27-Gy regimen, and 1.4% with the 26-Gy regimen. The 26-Gy regimen also had similar safety as the 40-Gy regimen.
These results were presented at the European Society for Radiology and Oncology 2020 Online Congress by Joanne S. Haviland, MSc, of the Institute of Cancer Research in London. Results were also published in The Lancet.
Ms. Haviland said that hypofractionated regimens are attractive because of their shorter overall treatment times, which translate to greater convenience and lower treatment costs.
The historic 5-week regimen (50 Gy in 25 fractions) has been replaced by a 3-week regimen (40 Gy in 15 fractions) in the United Kingdom and elsewhere, and ongoing efforts are exploring whether further hypofractionation can be achieved without compromising efficacy and safety.
“The FAST-Forward trial was the next step on from testing hypofractionated schedules evaluated in earlier trials, including the START trials in the early 2000s and the FAST trial, which published its 10-year results earlier this year,” Ms. Haviland explained.
FAST-Forward enrolled 4,096 women who had undergone breast-conserving surgery or mastectomy for early invasive breast cancer. The patients were randomized into the aforementioned groups for adjuvant whole-breast or chest-wall radiotherapy: 40 Gy in 15 fractions over 3 weeks, 27 Gy in 5 fractions over 5 days, or 26 Gy in 5 fractions over 5 days. Boosts were permitted for all regimens.
Relapse, safety, and patient reports
The median follow-up was 6 years. The 5-year rate of ipsilateral breast tumor relapse was 2.1% with the 40-Gy standard regimen, 1.7% with the 27-Gy hypofractionated regimen, and 1.4% with the 26-Gy hypofractionated regimen.
The upper bound of the 95% confidence interval for the difference comparing the hypofractionated regimens against the standard fell well within the 1.6% excess predefined for noninferiority for both the 27-Gy regimen and the 26-Gy regimen (0.9% and 0.3%, respectively).
The hazard ratio for ipsilateral breast tumor relapse, compared with the standard regimen, was 0.86 for the 27-Gy hypofractionated regimen and 0.67 for the 26-Gy hypofractionated regimen.
In terms of safety, the 5-year rate of late adverse effects of the breast or chest wall – distortion, shrinkage, induration, telangiectasia, or edema – rated as “moderate” or “marked” by clinicians was 10% with the standard regimen, 15% with the 27-Gy regimen (relative risk, 1.55 ; P < .001), and 12% with the 26-Gy regimen (RR, 1.19; P = .17).
Over the entire follow-up, women had significantly higher odds of all moderate or marked individual late adverse effects (except discomfort) with the 27-Gy regimen versus the standard regimen, whereas their odds were significantly higher only for induration and edema with the 26-Gy regimen.
However, absolute rates and risk differences between groups were small, Ms. Haviland pointed out. For example, the most common moderate or marked late adverse effect with the standard regimen was breast shrinkage, seen in 5% of patients, followed by discomfort, seen in 4%.
Patient-assessed change in breast appearance and shrinkage did not differ significantly across groups. But women in the 27-Gy group were more likely than peers in the standard regimen group to report a moderate or marked increase in breast hardness/firmness (21% vs. 14%; P = .008), and women in both the 27-Gy and 26-Gy groups were more likely to report moderate or marked breast swelling (5%; P = .007 and 4%; P = .02, respectively, vs. 2%).
A new standard
“We have shown noninferiority in terms of local tumor control for both 5-fraction schedules, compared with the control group of 40 Gy in 15 fractions,” Ms. Haviland summarized. “Late adverse effects in normal tissues were similar after 26 Gy in 5 fractions to 40 Gy in 15 fractions, and although rates were higher for the 27-Gy schedule, we noted that these are consistent with the historic standard of 50 Gy in 25 fractions.”
“There are obvious benefits to patients and health care systems of shorter radiotherapy treatments, particularly at the current time, and in fact, the COVID pandemic has accelerated uptake of the 26-Gy schedule around the world,” she added. “At a recent consensus meeting organized by the Royal College of Radiologists, the U.K. adopted the 26-Gy schedule as a new standard, also integrating this with partial breast irradiation, in close collaboration with the U.K. IMPORT Low trial.”
“This is very important work. I think this is one of the most important trials in the past few years. It has really changed practice,” commented session co-chair Ben Slotman, MD, PhD, of Vrije Universiteit Medical Center, Amsterdam, and AMC Amsterdam, who was not involved the trial.
Dr. Slotman wondered how extensive uptake of the new hypofractionated regimen has been. “I know it’s being used in the U.K. and the Netherlands, but do you have any idea about the rest of Europe? What do we need to make it the new standard?”
“I think there has been uptake in other countries in Europe and elsewhere around the world as well,” Ms. Haviland replied. But feedback suggests adoption has been tempered because of reservations related to the regimen’s safety in certain patient subgroups.
“We haven’t found any cause for concern in the subgroups, and also backed up by meta-analysis in the many patients randomized in the START trials,” she noted. “So I think there is very convincing evidence that it is safe as a new standard.”
FAST-Forward was sponsored by the Institute of Cancer Research and funded by the National Institute for Health Research Health Technology Assessment Programme. Ms. Haviland disclosed no conflicts of interest. Dr. Slotman has relationships with ViewRay and Varian Medical Systems.
SOURCE: Haviland J et al. ESTRO 2020, Abstract OC-0610.
The trial was designed to compare the standard regimen (40 Gy in 15 fractions over 3 weeks) with a higher-dose hypofractionated regimen (27 Gy in 5 fractions over 5 days) and a lower-dose hypofractionated regimen (26 Gy in 5 fractions over 5 days) in women who had undergone surgery for early invasive breast cancer.
The 5-year rate of ipsilateral breast tumor relapse was similar with all regimens – 2.1% with the 40-Gy regimen, 1.7% with the 27-Gy regimen, and 1.4% with the 26-Gy regimen. The 26-Gy regimen also had similar safety as the 40-Gy regimen.
These results were presented at the European Society for Radiology and Oncology 2020 Online Congress by Joanne S. Haviland, MSc, of the Institute of Cancer Research in London. Results were also published in The Lancet.
Ms. Haviland said that hypofractionated regimens are attractive because of their shorter overall treatment times, which translate to greater convenience and lower treatment costs.
The historic 5-week regimen (50 Gy in 25 fractions) has been replaced by a 3-week regimen (40 Gy in 15 fractions) in the United Kingdom and elsewhere, and ongoing efforts are exploring whether further hypofractionation can be achieved without compromising efficacy and safety.
“The FAST-Forward trial was the next step on from testing hypofractionated schedules evaluated in earlier trials, including the START trials in the early 2000s and the FAST trial, which published its 10-year results earlier this year,” Ms. Haviland explained.
FAST-Forward enrolled 4,096 women who had undergone breast-conserving surgery or mastectomy for early invasive breast cancer. The patients were randomized into the aforementioned groups for adjuvant whole-breast or chest-wall radiotherapy: 40 Gy in 15 fractions over 3 weeks, 27 Gy in 5 fractions over 5 days, or 26 Gy in 5 fractions over 5 days. Boosts were permitted for all regimens.
Relapse, safety, and patient reports
The median follow-up was 6 years. The 5-year rate of ipsilateral breast tumor relapse was 2.1% with the 40-Gy standard regimen, 1.7% with the 27-Gy hypofractionated regimen, and 1.4% with the 26-Gy hypofractionated regimen.
The upper bound of the 95% confidence interval for the difference comparing the hypofractionated regimens against the standard fell well within the 1.6% excess predefined for noninferiority for both the 27-Gy regimen and the 26-Gy regimen (0.9% and 0.3%, respectively).
The hazard ratio for ipsilateral breast tumor relapse, compared with the standard regimen, was 0.86 for the 27-Gy hypofractionated regimen and 0.67 for the 26-Gy hypofractionated regimen.
In terms of safety, the 5-year rate of late adverse effects of the breast or chest wall – distortion, shrinkage, induration, telangiectasia, or edema – rated as “moderate” or “marked” by clinicians was 10% with the standard regimen, 15% with the 27-Gy regimen (relative risk, 1.55 ; P < .001), and 12% with the 26-Gy regimen (RR, 1.19; P = .17).
Over the entire follow-up, women had significantly higher odds of all moderate or marked individual late adverse effects (except discomfort) with the 27-Gy regimen versus the standard regimen, whereas their odds were significantly higher only for induration and edema with the 26-Gy regimen.
However, absolute rates and risk differences between groups were small, Ms. Haviland pointed out. For example, the most common moderate or marked late adverse effect with the standard regimen was breast shrinkage, seen in 5% of patients, followed by discomfort, seen in 4%.
Patient-assessed change in breast appearance and shrinkage did not differ significantly across groups. But women in the 27-Gy group were more likely than peers in the standard regimen group to report a moderate or marked increase in breast hardness/firmness (21% vs. 14%; P = .008), and women in both the 27-Gy and 26-Gy groups were more likely to report moderate or marked breast swelling (5%; P = .007 and 4%; P = .02, respectively, vs. 2%).
A new standard
“We have shown noninferiority in terms of local tumor control for both 5-fraction schedules, compared with the control group of 40 Gy in 15 fractions,” Ms. Haviland summarized. “Late adverse effects in normal tissues were similar after 26 Gy in 5 fractions to 40 Gy in 15 fractions, and although rates were higher for the 27-Gy schedule, we noted that these are consistent with the historic standard of 50 Gy in 25 fractions.”
“There are obvious benefits to patients and health care systems of shorter radiotherapy treatments, particularly at the current time, and in fact, the COVID pandemic has accelerated uptake of the 26-Gy schedule around the world,” she added. “At a recent consensus meeting organized by the Royal College of Radiologists, the U.K. adopted the 26-Gy schedule as a new standard, also integrating this with partial breast irradiation, in close collaboration with the U.K. IMPORT Low trial.”
“This is very important work. I think this is one of the most important trials in the past few years. It has really changed practice,” commented session co-chair Ben Slotman, MD, PhD, of Vrije Universiteit Medical Center, Amsterdam, and AMC Amsterdam, who was not involved the trial.
Dr. Slotman wondered how extensive uptake of the new hypofractionated regimen has been. “I know it’s being used in the U.K. and the Netherlands, but do you have any idea about the rest of Europe? What do we need to make it the new standard?”
“I think there has been uptake in other countries in Europe and elsewhere around the world as well,” Ms. Haviland replied. But feedback suggests adoption has been tempered because of reservations related to the regimen’s safety in certain patient subgroups.
“We haven’t found any cause for concern in the subgroups, and also backed up by meta-analysis in the many patients randomized in the START trials,” she noted. “So I think there is very convincing evidence that it is safe as a new standard.”
FAST-Forward was sponsored by the Institute of Cancer Research and funded by the National Institute for Health Research Health Technology Assessment Programme. Ms. Haviland disclosed no conflicts of interest. Dr. Slotman has relationships with ViewRay and Varian Medical Systems.
SOURCE: Haviland J et al. ESTRO 2020, Abstract OC-0610.
The trial was designed to compare the standard regimen (40 Gy in 15 fractions over 3 weeks) with a higher-dose hypofractionated regimen (27 Gy in 5 fractions over 5 days) and a lower-dose hypofractionated regimen (26 Gy in 5 fractions over 5 days) in women who had undergone surgery for early invasive breast cancer.
The 5-year rate of ipsilateral breast tumor relapse was similar with all regimens – 2.1% with the 40-Gy regimen, 1.7% with the 27-Gy regimen, and 1.4% with the 26-Gy regimen. The 26-Gy regimen also had similar safety as the 40-Gy regimen.
These results were presented at the European Society for Radiology and Oncology 2020 Online Congress by Joanne S. Haviland, MSc, of the Institute of Cancer Research in London. Results were also published in The Lancet.
Ms. Haviland said that hypofractionated regimens are attractive because of their shorter overall treatment times, which translate to greater convenience and lower treatment costs.
The historic 5-week regimen (50 Gy in 25 fractions) has been replaced by a 3-week regimen (40 Gy in 15 fractions) in the United Kingdom and elsewhere, and ongoing efforts are exploring whether further hypofractionation can be achieved without compromising efficacy and safety.
“The FAST-Forward trial was the next step on from testing hypofractionated schedules evaluated in earlier trials, including the START trials in the early 2000s and the FAST trial, which published its 10-year results earlier this year,” Ms. Haviland explained.
FAST-Forward enrolled 4,096 women who had undergone breast-conserving surgery or mastectomy for early invasive breast cancer. The patients were randomized into the aforementioned groups for adjuvant whole-breast or chest-wall radiotherapy: 40 Gy in 15 fractions over 3 weeks, 27 Gy in 5 fractions over 5 days, or 26 Gy in 5 fractions over 5 days. Boosts were permitted for all regimens.
Relapse, safety, and patient reports
The median follow-up was 6 years. The 5-year rate of ipsilateral breast tumor relapse was 2.1% with the 40-Gy standard regimen, 1.7% with the 27-Gy hypofractionated regimen, and 1.4% with the 26-Gy hypofractionated regimen.
The upper bound of the 95% confidence interval for the difference comparing the hypofractionated regimens against the standard fell well within the 1.6% excess predefined for noninferiority for both the 27-Gy regimen and the 26-Gy regimen (0.9% and 0.3%, respectively).
The hazard ratio for ipsilateral breast tumor relapse, compared with the standard regimen, was 0.86 for the 27-Gy hypofractionated regimen and 0.67 for the 26-Gy hypofractionated regimen.
In terms of safety, the 5-year rate of late adverse effects of the breast or chest wall – distortion, shrinkage, induration, telangiectasia, or edema – rated as “moderate” or “marked” by clinicians was 10% with the standard regimen, 15% with the 27-Gy regimen (relative risk, 1.55 ; P < .001), and 12% with the 26-Gy regimen (RR, 1.19; P = .17).
Over the entire follow-up, women had significantly higher odds of all moderate or marked individual late adverse effects (except discomfort) with the 27-Gy regimen versus the standard regimen, whereas their odds were significantly higher only for induration and edema with the 26-Gy regimen.
However, absolute rates and risk differences between groups were small, Ms. Haviland pointed out. For example, the most common moderate or marked late adverse effect with the standard regimen was breast shrinkage, seen in 5% of patients, followed by discomfort, seen in 4%.
Patient-assessed change in breast appearance and shrinkage did not differ significantly across groups. But women in the 27-Gy group were more likely than peers in the standard regimen group to report a moderate or marked increase in breast hardness/firmness (21% vs. 14%; P = .008), and women in both the 27-Gy and 26-Gy groups were more likely to report moderate or marked breast swelling (5%; P = .007 and 4%; P = .02, respectively, vs. 2%).
A new standard
“We have shown noninferiority in terms of local tumor control for both 5-fraction schedules, compared with the control group of 40 Gy in 15 fractions,” Ms. Haviland summarized. “Late adverse effects in normal tissues were similar after 26 Gy in 5 fractions to 40 Gy in 15 fractions, and although rates were higher for the 27-Gy schedule, we noted that these are consistent with the historic standard of 50 Gy in 25 fractions.”
“There are obvious benefits to patients and health care systems of shorter radiotherapy treatments, particularly at the current time, and in fact, the COVID pandemic has accelerated uptake of the 26-Gy schedule around the world,” she added. “At a recent consensus meeting organized by the Royal College of Radiologists, the U.K. adopted the 26-Gy schedule as a new standard, also integrating this with partial breast irradiation, in close collaboration with the U.K. IMPORT Low trial.”
“This is very important work. I think this is one of the most important trials in the past few years. It has really changed practice,” commented session co-chair Ben Slotman, MD, PhD, of Vrije Universiteit Medical Center, Amsterdam, and AMC Amsterdam, who was not involved the trial.
Dr. Slotman wondered how extensive uptake of the new hypofractionated regimen has been. “I know it’s being used in the U.K. and the Netherlands, but do you have any idea about the rest of Europe? What do we need to make it the new standard?”
“I think there has been uptake in other countries in Europe and elsewhere around the world as well,” Ms. Haviland replied. But feedback suggests adoption has been tempered because of reservations related to the regimen’s safety in certain patient subgroups.
“We haven’t found any cause for concern in the subgroups, and also backed up by meta-analysis in the many patients randomized in the START trials,” she noted. “So I think there is very convincing evidence that it is safe as a new standard.”
FAST-Forward was sponsored by the Institute of Cancer Research and funded by the National Institute for Health Research Health Technology Assessment Programme. Ms. Haviland disclosed no conflicts of interest. Dr. Slotman has relationships with ViewRay and Varian Medical Systems.
SOURCE: Haviland J et al. ESTRO 2020, Abstract OC-0610.
FROM ESTRO 2020
‘Impressive’ local control with MRI-guided brachytherapy in cervical cancer
At 5 years, the rate of local control was 92%, and overall survival was 74%. However, nodal and systemic control rates were inferior for node-positive and high-risk patients, and nearly 15% of patients experienced grade 3-5 treatment-related morbidity.
These results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
Historically, brachytherapy dose has been fairly rigidly prescribed, based on dose points defined in two dimensions. By performing imaging before each brachytherapy implant, treatment parameters can be adapted to a patient’s anatomy, taking into account the positions of organs at risk and any tumor regression from prior treatment.
Richard Pötter, MD, emeritus professor at Medical University of Vienna, and colleagues tested MRI-guided adaptive brachytherapy in a multicenter cohort study.
The study’s disease outcome analysis included 1,341 women with cervical cancer of International Federation of Gynecology and Obstetrics stage IB–IVB (52% node positive) being treated with curative intent.
The women underwent definitive external beam radiotherapy (45-50 Gy, using either three-dimensional–conformal radiotherapy or intensity-modulated radiotherapy) with concurrent cisplatin chemotherapy, followed by MRI-guided adaptive brachytherapy based on MRI with the applicator in situ.
“There was no fixed dose prescription for brachytherapy, and there were no constraints for organs at risk,” Dr. Pötter explained. “But there was systematic joint reporting and contouring for the target and organs at risk, and also for doses and volumes.”
Nearly all patients were treated with adaptive MRI-based target and dose-volume and point parameters (99.1%), as well as with individualized multiparametric dose optimization (98.2%). The application technique was adapted, with intracavitary application alone used in 57% of patients, and both intracavitary and interstitial application in 43%.
Efficacy and toxicity
At a median follow-up of 51 months, 7.3% of patients had experienced a local failure, with 3.8% having an isolated local failure and 3.5% having synchronous nodal or systemic failure, Dr. Pötter reported.
The local failure rate was similar going from disease stage IB2 to IVA (8%-9%), even though the target volume more than doubled.
“This favorable result was due to an adaptation of dose, which was quite similar for the different stages and volumes. This is a major message of EMBRACE I,” Dr. Pötter commented.
The Kaplan-Meier–estimated 5-year rate of local control was 92% for the whole cohort. It was 98% in patients with stage IB1 disease and 91%-92% in patients with stage IB2–IVA disease.
The 5-year rate of overall survival was 74% for the entire cohort. It fell with stage, from 83% in patients with stage IB1 disease to 52% in patients with stage IVA disease.
For the entire population, the 5-year pelvic control rate was 87%, the 5-year cancer-specific survival was 79%, and the 5-year disease-free survival was 68%.
Overall, 14.6% of patients experienced grade 3-5 treatment-related morbidity at 5 years: 2.7% developed fistulas, 6.1% had vaginal toxicity, 6.5% had genitourinary toxicity, and 7.6% had gastrointestinal toxicity.
Room for improvement
“MRI-guided adaptive brachytherapy in locally advanced cervical cancer works in multicenter clinical practice, within such a study, with adaptation of the target and application technique, and multiparametric treatment planning and dose prescription,” Dr. Pötter summarized.
However, “the mature clinical outcomes appear challenging,” he added. Specifically, although the rate of local control was high, the rate of nodal control left room for improvement in node-positive patients, and the rates of systemic control and overall survival left room for improvement in high-risk patients.
In addition, “the grade 3-5 morbidity was limited per organ and per endpoint, but was considerable overall, and this asks for a reduction,” Dr. Pötter said.
Two of the areas needing improvement are being addressed in ongoing and planned research, according to Dr. Pötter. “The nodal part is already being addressed in EMBRACE II, intensifying treatment for node-positive patients through a simultaneous integrated boost and a very sophisticated probability planning concept, and also including more patients for paraaortic radiotherapy,” he elaborated. “For the systemic part, we have thought about [a study testing an] additional drug ... and there are thoughts for EMBRACE III to investigate such effect.”
A benchmark for brachytherapy
“This is the largest prospective cohort of patients treated with image-guided brachytherapy. The high rates of local control with long-term follow-up are impressive and speak to the clear value of high-quality brachytherapy,” commented Ann H. Klopp, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston, who was not involved in this study.
With its consistent reporting of detailed dose and toxicity data, the study establishes a benchmark for brachytherapy worldwide, Dr. Klopp said. It also better informs treatment decision-making in cases where replacing brachytherapy with external beam techniques is being considered.
Although MRI guidance is increasingly being used in brachytherapy, the latest studies on patterns of care suggest that overall use is still low, according to Dr. Klopp.
“The challenges are primarily logistical,” she elaborated. “MRI-compatible applicators must be placed, and patients need to wait for the scans to be performed, which can take an hour or more. In addition, the times that patients get scanned can be unpredictable based on procedure times, which can create practical challenges for scheduling. In some cases, cost may also be a deterrent.
“The bar is high for brachytherapy. It’s an excellent treatment modality that provides very high rates of local control with very low toxicity when done optimally,” Dr. Klopp concluded. “I do think that this experience provides very convincing evidence that the best brachytherapy is image-guided and requires care to monitor normal tissue doses in order to reduce the risk of long-term toxicity.”
The study was supported by unrestricted grants from Elekta and Varian. Dr. Pötter and Dr. Klopp disclosed no conflicts of interest.
SOURCE: Pötter R et al. ESTRO 2020, Abstract OC-0437.
At 5 years, the rate of local control was 92%, and overall survival was 74%. However, nodal and systemic control rates were inferior for node-positive and high-risk patients, and nearly 15% of patients experienced grade 3-5 treatment-related morbidity.
These results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
Historically, brachytherapy dose has been fairly rigidly prescribed, based on dose points defined in two dimensions. By performing imaging before each brachytherapy implant, treatment parameters can be adapted to a patient’s anatomy, taking into account the positions of organs at risk and any tumor regression from prior treatment.
Richard Pötter, MD, emeritus professor at Medical University of Vienna, and colleagues tested MRI-guided adaptive brachytherapy in a multicenter cohort study.
The study’s disease outcome analysis included 1,341 women with cervical cancer of International Federation of Gynecology and Obstetrics stage IB–IVB (52% node positive) being treated with curative intent.
The women underwent definitive external beam radiotherapy (45-50 Gy, using either three-dimensional–conformal radiotherapy or intensity-modulated radiotherapy) with concurrent cisplatin chemotherapy, followed by MRI-guided adaptive brachytherapy based on MRI with the applicator in situ.
“There was no fixed dose prescription for brachytherapy, and there were no constraints for organs at risk,” Dr. Pötter explained. “But there was systematic joint reporting and contouring for the target and organs at risk, and also for doses and volumes.”
Nearly all patients were treated with adaptive MRI-based target and dose-volume and point parameters (99.1%), as well as with individualized multiparametric dose optimization (98.2%). The application technique was adapted, with intracavitary application alone used in 57% of patients, and both intracavitary and interstitial application in 43%.
Efficacy and toxicity
At a median follow-up of 51 months, 7.3% of patients had experienced a local failure, with 3.8% having an isolated local failure and 3.5% having synchronous nodal or systemic failure, Dr. Pötter reported.
The local failure rate was similar going from disease stage IB2 to IVA (8%-9%), even though the target volume more than doubled.
“This favorable result was due to an adaptation of dose, which was quite similar for the different stages and volumes. This is a major message of EMBRACE I,” Dr. Pötter commented.
The Kaplan-Meier–estimated 5-year rate of local control was 92% for the whole cohort. It was 98% in patients with stage IB1 disease and 91%-92% in patients with stage IB2–IVA disease.
The 5-year rate of overall survival was 74% for the entire cohort. It fell with stage, from 83% in patients with stage IB1 disease to 52% in patients with stage IVA disease.
For the entire population, the 5-year pelvic control rate was 87%, the 5-year cancer-specific survival was 79%, and the 5-year disease-free survival was 68%.
Overall, 14.6% of patients experienced grade 3-5 treatment-related morbidity at 5 years: 2.7% developed fistulas, 6.1% had vaginal toxicity, 6.5% had genitourinary toxicity, and 7.6% had gastrointestinal toxicity.
Room for improvement
“MRI-guided adaptive brachytherapy in locally advanced cervical cancer works in multicenter clinical practice, within such a study, with adaptation of the target and application technique, and multiparametric treatment planning and dose prescription,” Dr. Pötter summarized.
However, “the mature clinical outcomes appear challenging,” he added. Specifically, although the rate of local control was high, the rate of nodal control left room for improvement in node-positive patients, and the rates of systemic control and overall survival left room for improvement in high-risk patients.
In addition, “the grade 3-5 morbidity was limited per organ and per endpoint, but was considerable overall, and this asks for a reduction,” Dr. Pötter said.
Two of the areas needing improvement are being addressed in ongoing and planned research, according to Dr. Pötter. “The nodal part is already being addressed in EMBRACE II, intensifying treatment for node-positive patients through a simultaneous integrated boost and a very sophisticated probability planning concept, and also including more patients for paraaortic radiotherapy,” he elaborated. “For the systemic part, we have thought about [a study testing an] additional drug ... and there are thoughts for EMBRACE III to investigate such effect.”
A benchmark for brachytherapy
“This is the largest prospective cohort of patients treated with image-guided brachytherapy. The high rates of local control with long-term follow-up are impressive and speak to the clear value of high-quality brachytherapy,” commented Ann H. Klopp, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston, who was not involved in this study.
With its consistent reporting of detailed dose and toxicity data, the study establishes a benchmark for brachytherapy worldwide, Dr. Klopp said. It also better informs treatment decision-making in cases where replacing brachytherapy with external beam techniques is being considered.
Although MRI guidance is increasingly being used in brachytherapy, the latest studies on patterns of care suggest that overall use is still low, according to Dr. Klopp.
“The challenges are primarily logistical,” she elaborated. “MRI-compatible applicators must be placed, and patients need to wait for the scans to be performed, which can take an hour or more. In addition, the times that patients get scanned can be unpredictable based on procedure times, which can create practical challenges for scheduling. In some cases, cost may also be a deterrent.
“The bar is high for brachytherapy. It’s an excellent treatment modality that provides very high rates of local control with very low toxicity when done optimally,” Dr. Klopp concluded. “I do think that this experience provides very convincing evidence that the best brachytherapy is image-guided and requires care to monitor normal tissue doses in order to reduce the risk of long-term toxicity.”
The study was supported by unrestricted grants from Elekta and Varian. Dr. Pötter and Dr. Klopp disclosed no conflicts of interest.
SOURCE: Pötter R et al. ESTRO 2020, Abstract OC-0437.
At 5 years, the rate of local control was 92%, and overall survival was 74%. However, nodal and systemic control rates were inferior for node-positive and high-risk patients, and nearly 15% of patients experienced grade 3-5 treatment-related morbidity.
These results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
Historically, brachytherapy dose has been fairly rigidly prescribed, based on dose points defined in two dimensions. By performing imaging before each brachytherapy implant, treatment parameters can be adapted to a patient’s anatomy, taking into account the positions of organs at risk and any tumor regression from prior treatment.
Richard Pötter, MD, emeritus professor at Medical University of Vienna, and colleagues tested MRI-guided adaptive brachytherapy in a multicenter cohort study.
The study’s disease outcome analysis included 1,341 women with cervical cancer of International Federation of Gynecology and Obstetrics stage IB–IVB (52% node positive) being treated with curative intent.
The women underwent definitive external beam radiotherapy (45-50 Gy, using either three-dimensional–conformal radiotherapy or intensity-modulated radiotherapy) with concurrent cisplatin chemotherapy, followed by MRI-guided adaptive brachytherapy based on MRI with the applicator in situ.
“There was no fixed dose prescription for brachytherapy, and there were no constraints for organs at risk,” Dr. Pötter explained. “But there was systematic joint reporting and contouring for the target and organs at risk, and also for doses and volumes.”
Nearly all patients were treated with adaptive MRI-based target and dose-volume and point parameters (99.1%), as well as with individualized multiparametric dose optimization (98.2%). The application technique was adapted, with intracavitary application alone used in 57% of patients, and both intracavitary and interstitial application in 43%.
Efficacy and toxicity
At a median follow-up of 51 months, 7.3% of patients had experienced a local failure, with 3.8% having an isolated local failure and 3.5% having synchronous nodal or systemic failure, Dr. Pötter reported.
The local failure rate was similar going from disease stage IB2 to IVA (8%-9%), even though the target volume more than doubled.
“This favorable result was due to an adaptation of dose, which was quite similar for the different stages and volumes. This is a major message of EMBRACE I,” Dr. Pötter commented.
The Kaplan-Meier–estimated 5-year rate of local control was 92% for the whole cohort. It was 98% in patients with stage IB1 disease and 91%-92% in patients with stage IB2–IVA disease.
The 5-year rate of overall survival was 74% for the entire cohort. It fell with stage, from 83% in patients with stage IB1 disease to 52% in patients with stage IVA disease.
For the entire population, the 5-year pelvic control rate was 87%, the 5-year cancer-specific survival was 79%, and the 5-year disease-free survival was 68%.
Overall, 14.6% of patients experienced grade 3-5 treatment-related morbidity at 5 years: 2.7% developed fistulas, 6.1% had vaginal toxicity, 6.5% had genitourinary toxicity, and 7.6% had gastrointestinal toxicity.
Room for improvement
“MRI-guided adaptive brachytherapy in locally advanced cervical cancer works in multicenter clinical practice, within such a study, with adaptation of the target and application technique, and multiparametric treatment planning and dose prescription,” Dr. Pötter summarized.
However, “the mature clinical outcomes appear challenging,” he added. Specifically, although the rate of local control was high, the rate of nodal control left room for improvement in node-positive patients, and the rates of systemic control and overall survival left room for improvement in high-risk patients.
In addition, “the grade 3-5 morbidity was limited per organ and per endpoint, but was considerable overall, and this asks for a reduction,” Dr. Pötter said.
Two of the areas needing improvement are being addressed in ongoing and planned research, according to Dr. Pötter. “The nodal part is already being addressed in EMBRACE II, intensifying treatment for node-positive patients through a simultaneous integrated boost and a very sophisticated probability planning concept, and also including more patients for paraaortic radiotherapy,” he elaborated. “For the systemic part, we have thought about [a study testing an] additional drug ... and there are thoughts for EMBRACE III to investigate such effect.”
A benchmark for brachytherapy
“This is the largest prospective cohort of patients treated with image-guided brachytherapy. The high rates of local control with long-term follow-up are impressive and speak to the clear value of high-quality brachytherapy,” commented Ann H. Klopp, MD, PhD, of the University of Texas MD Anderson Cancer Center, Houston, who was not involved in this study.
With its consistent reporting of detailed dose and toxicity data, the study establishes a benchmark for brachytherapy worldwide, Dr. Klopp said. It also better informs treatment decision-making in cases where replacing brachytherapy with external beam techniques is being considered.
Although MRI guidance is increasingly being used in brachytherapy, the latest studies on patterns of care suggest that overall use is still low, according to Dr. Klopp.
“The challenges are primarily logistical,” she elaborated. “MRI-compatible applicators must be placed, and patients need to wait for the scans to be performed, which can take an hour or more. In addition, the times that patients get scanned can be unpredictable based on procedure times, which can create practical challenges for scheduling. In some cases, cost may also be a deterrent.
“The bar is high for brachytherapy. It’s an excellent treatment modality that provides very high rates of local control with very low toxicity when done optimally,” Dr. Klopp concluded. “I do think that this experience provides very convincing evidence that the best brachytherapy is image-guided and requires care to monitor normal tissue doses in order to reduce the risk of long-term toxicity.”
The study was supported by unrestricted grants from Elekta and Varian. Dr. Pötter and Dr. Klopp disclosed no conflicts of interest.
SOURCE: Pötter R et al. ESTRO 2020, Abstract OC-0437.
FROM ESTRO 2020
Two different radiation boost strategies reduce local failures in NSCLC
The European PET-Boost trial finds that both of two strategies for delivering a radiation boost to locally advanced non–small cell lung cancer (NSCLC) tumors improve local control relative to that seen historically. Results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“From previous studies, we know that local recurrences have an important negative impact on survival,” said presenting author Saskia A. Cooke, an MD, PhD candidate in the department of Radiation Oncology Research, the Netherlands Cancer Institute, Amsterdam.
In addition, research shows that, despite advances in drug therapy, the most common site of progression in this population is intrathoracic.
“These results further underline the need to develop treatment strategies which effectively prevent intrathoracic and local recurrences,” Ms. Cooke said.
PET-Boost is a multicenter, randomized trial that enrolled patients with inoperable stage II or III NSCLC and a primary tumor measuring 4 cm or greater.
“The study was a phase 2 ‘pick the winner’ trial, which, by design, does not compare the two arms to one another but to a historic rate of outcome,” Ms. Cooke explained.
The patients were randomized evenly to receive the standard 66 Gy of radiotherapy given in 24 fractions of 2.75 Gy with one of two dose-escalation strategies: a boost to the whole primary tumor or a boost to only the tumor area having high metabolic activity, with a maximum standard uptake value (SUVmax) of at least 50% on the pretreatment FDG-PET scan.
For each patient, both plans were created before randomization, with the dose escalated as high as possible up to an organ-at-risk constraint, Ms. Cooke noted.
“A key element is that the two plans were made isotoxic by equaling the mean lung dose, and in both arms, the dose was delivered integrated into the 24 fractions, so without prolongation of the overall treatment time,” she said.
The trial’s goal was to improve the 1-year rate of freedom from local failure from the 70% seen historically with conventional chemoradiotherapy to 85%.
The trial was stopped early because of slow accrual, after enrollment of 107 patients, Ms. Cooke reported. The large majority received concurrent or sequential chemotherapy with their radiotherapy.
With a median follow-up of 12.6 months for the endpoint, the 1-year rate of freedom from local failure as determined on centrally reviewed CT scans was 97% with the whole-tumor boost and 91% with the PET-directed boost. The 2-year rates were 89% and 82%, respectively.
With a median follow-up of 61 months for the endpoint, the 1-year rate of overall survival was 77% with the whole-tumor boost and 62% with the PET-directed boost. The 2-year rates were 46% and 43%, respectively.
The two boost strategies increased acute and late toxicity over that seen historically, but not to unacceptable levels, as reported previously (Radiother Oncol. 2019;131:166-73).
“In this PET-Boost trial, using hypofractionated personalized dose escalation led to a very good local control rate, which, in both arms, was more than 90% at 1 year,” Ms. Cooke summarized.
In fact, values compare favorably with those seen in the phase 3 RTOG 0617 trial using conventional chemoradiotherapy and dose escalation, even though patients in that trial had smaller tumors.
“Survival, especially in the group treated with the homogeneous boost, was actually similar to the RTOG 0617 high-dose arm and also quite similar to the 1-year survival in the placebo arm of the PACIFIC trial,” she added. The somewhat poorer survival at 2 years in PET-Boost was likely related, in part, to the large tumor volumes and the mediastinal radiation dose, she speculated.
The investigators are now evaluating specific sites of failure and extrathoracic recurrences, as well as assessing associations of toxicity with organ-at-risk doses and quality of life.
“While further results of the trial are awaited, so far, we do believe that in selected patients with locally advanced NSCLC, hypofractionated dose escalation to the tumor is a very important subject for future research,” Ms. Cooke said.
The investigators plan to carry the whole-tumor boost strategy forward because it yields similar efficacy but is easier to plan.
Not ready for prime time
“Overall, this study conceptually is well designed as it is forward thinking and uses imaging to personalize radiation treatment, going to higher doses to active areas of disease based on FDG-PET imaging,” Arya Amini, MD, assistant clinical professor in the department of radiation oncology, City of Hope Comprehensive Cancer Center, Duarte, Calif., said in an interview.
However, he cautioned, local failure is challenging to assess at 1 year because of radiation-induced changes. In fact, more than a quarter of study patients had scans that were not evaluable for this reason. Furthermore, rates of late cardiac toxicity and esophageal stenosis are unknown.
“Longer-term follow-up is needed as the current data does not support dose escalation in unresectable lung cancer, specifically stage III NSCLC, based on RTOG 0617,” Dr. Amini said. “However, the overall survival detriment from dose escalation in RTOG 0617 could have been due to poor radiation techniques and toxicities including cardiac side effects, which we now better understand. The PET-Boost trial focuses on delivering higher doses of hypofractionated radiation based on PET, which essentially leads to a smaller area getting a radiation boost, which, in turn, should have less side effects.”
“This area of work will continue to be more exciting as more tumor-targeting radiotracers can be utilized with PET,” he predicted. “One of the future avenues in radiation oncology is incorporating novel imaging modalities including tumor-specific radiotracers with PET scans, for example, to dose-paint disease, delivering higher doses to more active parts of the primary and lymph nodes, while reducing doses to less active areas, which potentially could lead to higher rates of local control with minimal side effects.”
The trial was sponsored by The Netherlands Cancer Institute. Ms. Cooke and Dr. Amini disclosed no conflicts of interest.
SOURCE: Lalezari F et al. ESTRO 2020. Abstract OC-0609.
The European PET-Boost trial finds that both of two strategies for delivering a radiation boost to locally advanced non–small cell lung cancer (NSCLC) tumors improve local control relative to that seen historically. Results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“From previous studies, we know that local recurrences have an important negative impact on survival,” said presenting author Saskia A. Cooke, an MD, PhD candidate in the department of Radiation Oncology Research, the Netherlands Cancer Institute, Amsterdam.
In addition, research shows that, despite advances in drug therapy, the most common site of progression in this population is intrathoracic.
“These results further underline the need to develop treatment strategies which effectively prevent intrathoracic and local recurrences,” Ms. Cooke said.
PET-Boost is a multicenter, randomized trial that enrolled patients with inoperable stage II or III NSCLC and a primary tumor measuring 4 cm or greater.
“The study was a phase 2 ‘pick the winner’ trial, which, by design, does not compare the two arms to one another but to a historic rate of outcome,” Ms. Cooke explained.
The patients were randomized evenly to receive the standard 66 Gy of radiotherapy given in 24 fractions of 2.75 Gy with one of two dose-escalation strategies: a boost to the whole primary tumor or a boost to only the tumor area having high metabolic activity, with a maximum standard uptake value (SUVmax) of at least 50% on the pretreatment FDG-PET scan.
For each patient, both plans were created before randomization, with the dose escalated as high as possible up to an organ-at-risk constraint, Ms. Cooke noted.
“A key element is that the two plans were made isotoxic by equaling the mean lung dose, and in both arms, the dose was delivered integrated into the 24 fractions, so without prolongation of the overall treatment time,” she said.
The trial’s goal was to improve the 1-year rate of freedom from local failure from the 70% seen historically with conventional chemoradiotherapy to 85%.
The trial was stopped early because of slow accrual, after enrollment of 107 patients, Ms. Cooke reported. The large majority received concurrent or sequential chemotherapy with their radiotherapy.
With a median follow-up of 12.6 months for the endpoint, the 1-year rate of freedom from local failure as determined on centrally reviewed CT scans was 97% with the whole-tumor boost and 91% with the PET-directed boost. The 2-year rates were 89% and 82%, respectively.
With a median follow-up of 61 months for the endpoint, the 1-year rate of overall survival was 77% with the whole-tumor boost and 62% with the PET-directed boost. The 2-year rates were 46% and 43%, respectively.
The two boost strategies increased acute and late toxicity over that seen historically, but not to unacceptable levels, as reported previously (Radiother Oncol. 2019;131:166-73).
“In this PET-Boost trial, using hypofractionated personalized dose escalation led to a very good local control rate, which, in both arms, was more than 90% at 1 year,” Ms. Cooke summarized.
In fact, values compare favorably with those seen in the phase 3 RTOG 0617 trial using conventional chemoradiotherapy and dose escalation, even though patients in that trial had smaller tumors.
“Survival, especially in the group treated with the homogeneous boost, was actually similar to the RTOG 0617 high-dose arm and also quite similar to the 1-year survival in the placebo arm of the PACIFIC trial,” she added. The somewhat poorer survival at 2 years in PET-Boost was likely related, in part, to the large tumor volumes and the mediastinal radiation dose, she speculated.
The investigators are now evaluating specific sites of failure and extrathoracic recurrences, as well as assessing associations of toxicity with organ-at-risk doses and quality of life.
“While further results of the trial are awaited, so far, we do believe that in selected patients with locally advanced NSCLC, hypofractionated dose escalation to the tumor is a very important subject for future research,” Ms. Cooke said.
The investigators plan to carry the whole-tumor boost strategy forward because it yields similar efficacy but is easier to plan.
Not ready for prime time
“Overall, this study conceptually is well designed as it is forward thinking and uses imaging to personalize radiation treatment, going to higher doses to active areas of disease based on FDG-PET imaging,” Arya Amini, MD, assistant clinical professor in the department of radiation oncology, City of Hope Comprehensive Cancer Center, Duarte, Calif., said in an interview.
However, he cautioned, local failure is challenging to assess at 1 year because of radiation-induced changes. In fact, more than a quarter of study patients had scans that were not evaluable for this reason. Furthermore, rates of late cardiac toxicity and esophageal stenosis are unknown.
“Longer-term follow-up is needed as the current data does not support dose escalation in unresectable lung cancer, specifically stage III NSCLC, based on RTOG 0617,” Dr. Amini said. “However, the overall survival detriment from dose escalation in RTOG 0617 could have been due to poor radiation techniques and toxicities including cardiac side effects, which we now better understand. The PET-Boost trial focuses on delivering higher doses of hypofractionated radiation based on PET, which essentially leads to a smaller area getting a radiation boost, which, in turn, should have less side effects.”
“This area of work will continue to be more exciting as more tumor-targeting radiotracers can be utilized with PET,” he predicted. “One of the future avenues in radiation oncology is incorporating novel imaging modalities including tumor-specific radiotracers with PET scans, for example, to dose-paint disease, delivering higher doses to more active parts of the primary and lymph nodes, while reducing doses to less active areas, which potentially could lead to higher rates of local control with minimal side effects.”
The trial was sponsored by The Netherlands Cancer Institute. Ms. Cooke and Dr. Amini disclosed no conflicts of interest.
SOURCE: Lalezari F et al. ESTRO 2020. Abstract OC-0609.
The European PET-Boost trial finds that both of two strategies for delivering a radiation boost to locally advanced non–small cell lung cancer (NSCLC) tumors improve local control relative to that seen historically. Results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“From previous studies, we know that local recurrences have an important negative impact on survival,” said presenting author Saskia A. Cooke, an MD, PhD candidate in the department of Radiation Oncology Research, the Netherlands Cancer Institute, Amsterdam.
In addition, research shows that, despite advances in drug therapy, the most common site of progression in this population is intrathoracic.
“These results further underline the need to develop treatment strategies which effectively prevent intrathoracic and local recurrences,” Ms. Cooke said.
PET-Boost is a multicenter, randomized trial that enrolled patients with inoperable stage II or III NSCLC and a primary tumor measuring 4 cm or greater.
“The study was a phase 2 ‘pick the winner’ trial, which, by design, does not compare the two arms to one another but to a historic rate of outcome,” Ms. Cooke explained.
The patients were randomized evenly to receive the standard 66 Gy of radiotherapy given in 24 fractions of 2.75 Gy with one of two dose-escalation strategies: a boost to the whole primary tumor or a boost to only the tumor area having high metabolic activity, with a maximum standard uptake value (SUVmax) of at least 50% on the pretreatment FDG-PET scan.
For each patient, both plans were created before randomization, with the dose escalated as high as possible up to an organ-at-risk constraint, Ms. Cooke noted.
“A key element is that the two plans were made isotoxic by equaling the mean lung dose, and in both arms, the dose was delivered integrated into the 24 fractions, so without prolongation of the overall treatment time,” she said.
The trial’s goal was to improve the 1-year rate of freedom from local failure from the 70% seen historically with conventional chemoradiotherapy to 85%.
The trial was stopped early because of slow accrual, after enrollment of 107 patients, Ms. Cooke reported. The large majority received concurrent or sequential chemotherapy with their radiotherapy.
With a median follow-up of 12.6 months for the endpoint, the 1-year rate of freedom from local failure as determined on centrally reviewed CT scans was 97% with the whole-tumor boost and 91% with the PET-directed boost. The 2-year rates were 89% and 82%, respectively.
With a median follow-up of 61 months for the endpoint, the 1-year rate of overall survival was 77% with the whole-tumor boost and 62% with the PET-directed boost. The 2-year rates were 46% and 43%, respectively.
The two boost strategies increased acute and late toxicity over that seen historically, but not to unacceptable levels, as reported previously (Radiother Oncol. 2019;131:166-73).
“In this PET-Boost trial, using hypofractionated personalized dose escalation led to a very good local control rate, which, in both arms, was more than 90% at 1 year,” Ms. Cooke summarized.
In fact, values compare favorably with those seen in the phase 3 RTOG 0617 trial using conventional chemoradiotherapy and dose escalation, even though patients in that trial had smaller tumors.
“Survival, especially in the group treated with the homogeneous boost, was actually similar to the RTOG 0617 high-dose arm and also quite similar to the 1-year survival in the placebo arm of the PACIFIC trial,” she added. The somewhat poorer survival at 2 years in PET-Boost was likely related, in part, to the large tumor volumes and the mediastinal radiation dose, she speculated.
The investigators are now evaluating specific sites of failure and extrathoracic recurrences, as well as assessing associations of toxicity with organ-at-risk doses and quality of life.
“While further results of the trial are awaited, so far, we do believe that in selected patients with locally advanced NSCLC, hypofractionated dose escalation to the tumor is a very important subject for future research,” Ms. Cooke said.
The investigators plan to carry the whole-tumor boost strategy forward because it yields similar efficacy but is easier to plan.
Not ready for prime time
“Overall, this study conceptually is well designed as it is forward thinking and uses imaging to personalize radiation treatment, going to higher doses to active areas of disease based on FDG-PET imaging,” Arya Amini, MD, assistant clinical professor in the department of radiation oncology, City of Hope Comprehensive Cancer Center, Duarte, Calif., said in an interview.
However, he cautioned, local failure is challenging to assess at 1 year because of radiation-induced changes. In fact, more than a quarter of study patients had scans that were not evaluable for this reason. Furthermore, rates of late cardiac toxicity and esophageal stenosis are unknown.
“Longer-term follow-up is needed as the current data does not support dose escalation in unresectable lung cancer, specifically stage III NSCLC, based on RTOG 0617,” Dr. Amini said. “However, the overall survival detriment from dose escalation in RTOG 0617 could have been due to poor radiation techniques and toxicities including cardiac side effects, which we now better understand. The PET-Boost trial focuses on delivering higher doses of hypofractionated radiation based on PET, which essentially leads to a smaller area getting a radiation boost, which, in turn, should have less side effects.”
“This area of work will continue to be more exciting as more tumor-targeting radiotracers can be utilized with PET,” he predicted. “One of the future avenues in radiation oncology is incorporating novel imaging modalities including tumor-specific radiotracers with PET scans, for example, to dose-paint disease, delivering higher doses to more active parts of the primary and lymph nodes, while reducing doses to less active areas, which potentially could lead to higher rates of local control with minimal side effects.”
The trial was sponsored by The Netherlands Cancer Institute. Ms. Cooke and Dr. Amini disclosed no conflicts of interest.
SOURCE: Lalezari F et al. ESTRO 2020. Abstract OC-0609.
FROM ESTRO 2020
Long-term APBI cosmetic, toxicity data reported
Long-term cosmetic and toxicity outcomes are good for both accelerated partial breast irradiation (APBI) delivered with 3D-conformal radiotherapy and whole-breast irradiation (WBI), with the latter having a slight edge, the IRMA trial shows.
Findings were reported at the European Society for Radiology and Oncology 2020 Online Congress by Bruno Meduri, MD, a radiation oncologist at University Hospital of Modena, Italy.
Uptake of APBI has increased since it was approved nearly 2 decades ago. However, its long-term outcomes are still being parsed, and issues such as appropriate patient selection and optimal delivery technique are still being clarified (Curr Breast Cancer Rep. 2020;18:1-10).
IRMA is a European, multicenter, phase 3 randomized controlled trial conducted among 3,279 women aged 49 years and older who underwent breast-conserving surgery for early-stage breast cancer (measuring <3 cm in diameter, and pathologic N0 or N1) with negative resection margins.
The women were randomized to APBI using 3D-conformal radiotherapy (38.5 Gy in 10 fractions, twice daily) or conventional or hypofractionated WBI (50.0 Gy in 25 fractions, once daily). All additionally received adjuvant therapy according to institutional guidelines.
Patients and physicians separately rated cosmetic outcomes on a 4-point scale using the untreated breast as a reference, and toxicity was graded with the Radiation Therapy Oncology Group (RTOG) scale.
Over a median follow-up of 5 years, patients rated cosmesis more favorably than physicians did at all time points, and there was a trend toward slight worsening of cosmesis in the APBI group with time, Dr. Meduri reported.
At 1 year, cosmesis did not differ significantly between treatment groups regardless of the rater. But compared with the WBI group, the APBI group more often had patient-rated fair to poor cosmesis at 3 years (12.7% vs. 9.4%; P =.02) and at 5 years (15.0% vs. 10.1%; P = .007), as well as physician-rated fair to poor cosmesis at 3 years (18.0% vs. 13.1%; P = .003) and at 5 years (18.4% vs. 14.2%; P = .04).
Women treated with APBI had less acute skin toxicity (P < .001), with 4.9% developing grade 2 toxicity, compared with 21.4% of peers treated with WBI. Late skin toxicity was also less common in the APBI group overall (P < .001), but the rate of grade 3 or 4 late skin toxicity was similar.
On the other hand, the APBI group had more late bone toxicity overall (P < .001) and late bone toxicity of grade 3 or 4 (1.0% vs. 0%; P < .05), as well as more late soft tissue (subcutaneous) toxicity overall (P < .001) and late soft tissue toxicity of grade 3 or 4 (2.6% vs. 1.1%; P < .05).
The two groups had essentially the same late lung toxicity.
Women treated with APBI had higher 5-year cumulative incidences of soft tissue toxicity of grade 2 or worse (29.7% vs. 17.9%; P < .0001) and grade 3 or worse (2.6% vs. 1.1%; P = .0016). Cumulative incidences of skin toxicity of these grades did not differ significantly.
Importantly, the prevalences of late soft tissue and skin toxicity at 5 years were much lower than the cumulative incidences, Dr. Meduri noted. “This means that the side effects in some patients tend to resolve over time.”
Although the prevalence of grade 2-4 skin toxicity increased slightly at 3 years and 5 years in both groups, the prevalence of grade 2-4 soft tissue toxicity was stable.
Finally, the volume that received at least 38.5 Gy of radiation was higher for patients who developed late grade 3 or 4 bone toxicity than for those who did not (2.1 vs. 0.82 cc; P = .027), whereas other dosimetric parameters were similar.
“The toxicity of the whole cohort was very low,” Dr. Meduri summarized. “APBI was associated with a slightly higher rate of late soft tissue and bone toxicity, with a slight decrease in cosmetic outcome at 5 years. But longer follow-up is needed to confirm these results.”
The IRMA findings confirm previous results from the RAPID trial showing that APBI delivered via 3D-conformal radiotherapy may be associated with increased rates of toxicity, Chirag Shah, MD, a radiation oncologist at the Cleveland Clinic in Ohio, said in an interview.
“While cancer control outcomes were not presented, the toxicity outcomes are important and validate why many are moving away from 3D-conformal radiotherapy APBI,” he elaborated. “We are seeing increased use of APBI in some centers in the U.S., though there has been a greater shift to IMRT [intensity-modulated radiation therapy] based on 10-year data from the Florence randomized trial, which showed reduced side effects.”
“I think the results of this study are practice-confirming,” Dr. Shah concluded. “Moving forward, shorter APBI schedules will be considered as we now have 5-fraction whole-breast regimens available, as assessed in the FAST and FAST-Forward trials.”
Dr. Meduri disclosed expert board service for MSD, and financial support for attending congresses from Ipsen, AstraZeneca, and Merck. The trial was sponsored by Regione Emilia-Romagna. Dr. Shah disclosed consulting for Impedimed and PreludeDX, and receiving grants from Varian, VisionRT, and PreludeDX.
SOURCE: Meduri B et al. ESTRO 2020. Abstract OC-0611.
Long-term cosmetic and toxicity outcomes are good for both accelerated partial breast irradiation (APBI) delivered with 3D-conformal radiotherapy and whole-breast irradiation (WBI), with the latter having a slight edge, the IRMA trial shows.
Findings were reported at the European Society for Radiology and Oncology 2020 Online Congress by Bruno Meduri, MD, a radiation oncologist at University Hospital of Modena, Italy.
Uptake of APBI has increased since it was approved nearly 2 decades ago. However, its long-term outcomes are still being parsed, and issues such as appropriate patient selection and optimal delivery technique are still being clarified (Curr Breast Cancer Rep. 2020;18:1-10).
IRMA is a European, multicenter, phase 3 randomized controlled trial conducted among 3,279 women aged 49 years and older who underwent breast-conserving surgery for early-stage breast cancer (measuring <3 cm in diameter, and pathologic N0 or N1) with negative resection margins.
The women were randomized to APBI using 3D-conformal radiotherapy (38.5 Gy in 10 fractions, twice daily) or conventional or hypofractionated WBI (50.0 Gy in 25 fractions, once daily). All additionally received adjuvant therapy according to institutional guidelines.
Patients and physicians separately rated cosmetic outcomes on a 4-point scale using the untreated breast as a reference, and toxicity was graded with the Radiation Therapy Oncology Group (RTOG) scale.
Over a median follow-up of 5 years, patients rated cosmesis more favorably than physicians did at all time points, and there was a trend toward slight worsening of cosmesis in the APBI group with time, Dr. Meduri reported.
At 1 year, cosmesis did not differ significantly between treatment groups regardless of the rater. But compared with the WBI group, the APBI group more often had patient-rated fair to poor cosmesis at 3 years (12.7% vs. 9.4%; P =.02) and at 5 years (15.0% vs. 10.1%; P = .007), as well as physician-rated fair to poor cosmesis at 3 years (18.0% vs. 13.1%; P = .003) and at 5 years (18.4% vs. 14.2%; P = .04).
Women treated with APBI had less acute skin toxicity (P < .001), with 4.9% developing grade 2 toxicity, compared with 21.4% of peers treated with WBI. Late skin toxicity was also less common in the APBI group overall (P < .001), but the rate of grade 3 or 4 late skin toxicity was similar.
On the other hand, the APBI group had more late bone toxicity overall (P < .001) and late bone toxicity of grade 3 or 4 (1.0% vs. 0%; P < .05), as well as more late soft tissue (subcutaneous) toxicity overall (P < .001) and late soft tissue toxicity of grade 3 or 4 (2.6% vs. 1.1%; P < .05).
The two groups had essentially the same late lung toxicity.
Women treated with APBI had higher 5-year cumulative incidences of soft tissue toxicity of grade 2 or worse (29.7% vs. 17.9%; P < .0001) and grade 3 or worse (2.6% vs. 1.1%; P = .0016). Cumulative incidences of skin toxicity of these grades did not differ significantly.
Importantly, the prevalences of late soft tissue and skin toxicity at 5 years were much lower than the cumulative incidences, Dr. Meduri noted. “This means that the side effects in some patients tend to resolve over time.”
Although the prevalence of grade 2-4 skin toxicity increased slightly at 3 years and 5 years in both groups, the prevalence of grade 2-4 soft tissue toxicity was stable.
Finally, the volume that received at least 38.5 Gy of radiation was higher for patients who developed late grade 3 or 4 bone toxicity than for those who did not (2.1 vs. 0.82 cc; P = .027), whereas other dosimetric parameters were similar.
“The toxicity of the whole cohort was very low,” Dr. Meduri summarized. “APBI was associated with a slightly higher rate of late soft tissue and bone toxicity, with a slight decrease in cosmetic outcome at 5 years. But longer follow-up is needed to confirm these results.”
The IRMA findings confirm previous results from the RAPID trial showing that APBI delivered via 3D-conformal radiotherapy may be associated with increased rates of toxicity, Chirag Shah, MD, a radiation oncologist at the Cleveland Clinic in Ohio, said in an interview.
“While cancer control outcomes were not presented, the toxicity outcomes are important and validate why many are moving away from 3D-conformal radiotherapy APBI,” he elaborated. “We are seeing increased use of APBI in some centers in the U.S., though there has been a greater shift to IMRT [intensity-modulated radiation therapy] based on 10-year data from the Florence randomized trial, which showed reduced side effects.”
“I think the results of this study are practice-confirming,” Dr. Shah concluded. “Moving forward, shorter APBI schedules will be considered as we now have 5-fraction whole-breast regimens available, as assessed in the FAST and FAST-Forward trials.”
Dr. Meduri disclosed expert board service for MSD, and financial support for attending congresses from Ipsen, AstraZeneca, and Merck. The trial was sponsored by Regione Emilia-Romagna. Dr. Shah disclosed consulting for Impedimed and PreludeDX, and receiving grants from Varian, VisionRT, and PreludeDX.
SOURCE: Meduri B et al. ESTRO 2020. Abstract OC-0611.
Long-term cosmetic and toxicity outcomes are good for both accelerated partial breast irradiation (APBI) delivered with 3D-conformal radiotherapy and whole-breast irradiation (WBI), with the latter having a slight edge, the IRMA trial shows.
Findings were reported at the European Society for Radiology and Oncology 2020 Online Congress by Bruno Meduri, MD, a radiation oncologist at University Hospital of Modena, Italy.
Uptake of APBI has increased since it was approved nearly 2 decades ago. However, its long-term outcomes are still being parsed, and issues such as appropriate patient selection and optimal delivery technique are still being clarified (Curr Breast Cancer Rep. 2020;18:1-10).
IRMA is a European, multicenter, phase 3 randomized controlled trial conducted among 3,279 women aged 49 years and older who underwent breast-conserving surgery for early-stage breast cancer (measuring <3 cm in diameter, and pathologic N0 or N1) with negative resection margins.
The women were randomized to APBI using 3D-conformal radiotherapy (38.5 Gy in 10 fractions, twice daily) or conventional or hypofractionated WBI (50.0 Gy in 25 fractions, once daily). All additionally received adjuvant therapy according to institutional guidelines.
Patients and physicians separately rated cosmetic outcomes on a 4-point scale using the untreated breast as a reference, and toxicity was graded with the Radiation Therapy Oncology Group (RTOG) scale.
Over a median follow-up of 5 years, patients rated cosmesis more favorably than physicians did at all time points, and there was a trend toward slight worsening of cosmesis in the APBI group with time, Dr. Meduri reported.
At 1 year, cosmesis did not differ significantly between treatment groups regardless of the rater. But compared with the WBI group, the APBI group more often had patient-rated fair to poor cosmesis at 3 years (12.7% vs. 9.4%; P =.02) and at 5 years (15.0% vs. 10.1%; P = .007), as well as physician-rated fair to poor cosmesis at 3 years (18.0% vs. 13.1%; P = .003) and at 5 years (18.4% vs. 14.2%; P = .04).
Women treated with APBI had less acute skin toxicity (P < .001), with 4.9% developing grade 2 toxicity, compared with 21.4% of peers treated with WBI. Late skin toxicity was also less common in the APBI group overall (P < .001), but the rate of grade 3 or 4 late skin toxicity was similar.
On the other hand, the APBI group had more late bone toxicity overall (P < .001) and late bone toxicity of grade 3 or 4 (1.0% vs. 0%; P < .05), as well as more late soft tissue (subcutaneous) toxicity overall (P < .001) and late soft tissue toxicity of grade 3 or 4 (2.6% vs. 1.1%; P < .05).
The two groups had essentially the same late lung toxicity.
Women treated with APBI had higher 5-year cumulative incidences of soft tissue toxicity of grade 2 or worse (29.7% vs. 17.9%; P < .0001) and grade 3 or worse (2.6% vs. 1.1%; P = .0016). Cumulative incidences of skin toxicity of these grades did not differ significantly.
Importantly, the prevalences of late soft tissue and skin toxicity at 5 years were much lower than the cumulative incidences, Dr. Meduri noted. “This means that the side effects in some patients tend to resolve over time.”
Although the prevalence of grade 2-4 skin toxicity increased slightly at 3 years and 5 years in both groups, the prevalence of grade 2-4 soft tissue toxicity was stable.
Finally, the volume that received at least 38.5 Gy of radiation was higher for patients who developed late grade 3 or 4 bone toxicity than for those who did not (2.1 vs. 0.82 cc; P = .027), whereas other dosimetric parameters were similar.
“The toxicity of the whole cohort was very low,” Dr. Meduri summarized. “APBI was associated with a slightly higher rate of late soft tissue and bone toxicity, with a slight decrease in cosmetic outcome at 5 years. But longer follow-up is needed to confirm these results.”
The IRMA findings confirm previous results from the RAPID trial showing that APBI delivered via 3D-conformal radiotherapy may be associated with increased rates of toxicity, Chirag Shah, MD, a radiation oncologist at the Cleveland Clinic in Ohio, said in an interview.
“While cancer control outcomes were not presented, the toxicity outcomes are important and validate why many are moving away from 3D-conformal radiotherapy APBI,” he elaborated. “We are seeing increased use of APBI in some centers in the U.S., though there has been a greater shift to IMRT [intensity-modulated radiation therapy] based on 10-year data from the Florence randomized trial, which showed reduced side effects.”
“I think the results of this study are practice-confirming,” Dr. Shah concluded. “Moving forward, shorter APBI schedules will be considered as we now have 5-fraction whole-breast regimens available, as assessed in the FAST and FAST-Forward trials.”
Dr. Meduri disclosed expert board service for MSD, and financial support for attending congresses from Ipsen, AstraZeneca, and Merck. The trial was sponsored by Regione Emilia-Romagna. Dr. Shah disclosed consulting for Impedimed and PreludeDX, and receiving grants from Varian, VisionRT, and PreludeDX.
SOURCE: Meduri B et al. ESTRO 2020. Abstract OC-0611.
FROM ESTRO 2020
Focal radiation boost nets better outcomes in prostate cancer
The results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“We know that local recurrences most often occur at the location of the primary tumor or the dominant intraprostatic lesion, and we also know that biochemical disease–free survival improves with increasing dose to the whole prostate gland,” said principal investigator Linda G.W. Kerkmeijer, MD, PhD, of Radboud University Medical Center Nijmegen, the Netherlands.
However, “with whole-gland dose escalation, increased toxicity has been observed in both external-beam and brachytherapy trials,” she added.
FLAME trial details
A total of 571 patients took part in the FLAME trial, which is a collaboration of UMC Utrecht, the Netherlands Cancer Institute, University Hospitals Leuven, and Radboudumc.
The patients were randomized evenly to standard radiation therapy alone (77 Gy to the whole prostate in 35 fractions of 2.2 Gy) or with an integrated boost to the macroscopically visible tumor on multiparametric MRI (to reach a total dose of up to 95 Gy in 35 fractions of 2.7 Gy).
In treatment planning, the organs-at-risk constraints were prioritized over the focal boost dose, Dr. Kerkmeijer pointed out.
A majority of patients (84%) had high-risk disease, and two-thirds received hormonal therapy (usually in the adjuvant setting) with equal distribution across study arms, she reported.
With a median follow-up of 72 months, the 5-year rate of biochemical disease–free survival, the trial’s primary endpoint, was superior with the addition of the focal boost as compared with standard radiation therapy alone (92% vs. 85%; P < .001).
The boost also netted significantly better disease-free survival (P < .001).
The arms were similar on distant metastasis–free survival (P = .26), prostate cancer–specific survival (P = .49), and overall survival (P = .50), although longer follow-up is needed to fully assess these outcomes, Dr. Kerkmeijer noted.
The boost and standard therapy arms had much the same late grade 3 or higher genitourinary toxicity (5.6% vs. 3.5%; P = .22) and late grade 3 or higher gastrointestinal toxicity (1.4% vs. 1.4%; P = .99).
The arms were essentially identical on long-term patient-reported urinary symptoms, bowel symptoms, sexual activity, and sexual function, as measured with the EORTC QLQ-PR25 tool and detailed in a companion presentation (abstract OC-0315).
‘A standard option’ and next steps
“FLAME is the first phase 3 randomized controlled trial to show that focal boosting works and that biochemical recurrence was reduced at 5 years,” Dr. Kerkmeijer said. “We propose that the FLAME scheme can be considered as a standard option for patients with intermediate- but especially high-risk prostate cancer.”
“For patients, biochemical recurrence may have impact, as this causes additional follow-up and diagnostic exams, potential anxiety, and potential side effects of subsequent treatments,” she added. “Biochemical recurrences were reduced by almost half and at no additional cost and no additional toxicity by this FLAME isotoxic approach and by using conventional radiotherapy techniques.”
The next step is pairing the boost with ultra-hypofractionation, which requires highly accurate targeting, Dr. Kerkmeijer said. In fact, favorable early toxicity results of the subsequent Hypo-FLAME trial, which tested this strategy, were also reported at the congress (abstract OC-0209), and a trial taking the strategy even further, Hypo-FLAME 2.0, is ongoing.
“The FLAME trial’s results are probably true but may have been impacted by the use of hormonal therapy,” Anthony V. D’Amico, MD, PhD, of the Dana Farber Cancer Institute and Harvard Medical School, Boston, said in an interview.
Any imbalance in the use and duration of hormonal therapy, given that it can delay the time to prostate-specific antigen failure, could lead to overestimation or underestimation of the benefit of the focal boost, with respect to the primary endpoint of the study, he elaborated. Typical durations of this therapy range from 4 to 6 months for patients with intermediate-risk disease and from 18 to 36 months for patients with high-risk disease.
“So it’s important to know and to adjust not just for hormonal therapy use, but for duration between the two arms, stratified by risk group, in a multivariable regression analysis,” Dr. D’Amico concluded.
The FLAME trial was funded by the Dutch Cancer Society and Stand Up Against Cancer Belgium. Dr. Kerkmeijer and Dr. D’Amico disclosed having no conflicts of interest.
SOURCE: De Boer HCJ et al. ESTRO 2020. Abstract OC-0612.
The results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“We know that local recurrences most often occur at the location of the primary tumor or the dominant intraprostatic lesion, and we also know that biochemical disease–free survival improves with increasing dose to the whole prostate gland,” said principal investigator Linda G.W. Kerkmeijer, MD, PhD, of Radboud University Medical Center Nijmegen, the Netherlands.
However, “with whole-gland dose escalation, increased toxicity has been observed in both external-beam and brachytherapy trials,” she added.
FLAME trial details
A total of 571 patients took part in the FLAME trial, which is a collaboration of UMC Utrecht, the Netherlands Cancer Institute, University Hospitals Leuven, and Radboudumc.
The patients were randomized evenly to standard radiation therapy alone (77 Gy to the whole prostate in 35 fractions of 2.2 Gy) or with an integrated boost to the macroscopically visible tumor on multiparametric MRI (to reach a total dose of up to 95 Gy in 35 fractions of 2.7 Gy).
In treatment planning, the organs-at-risk constraints were prioritized over the focal boost dose, Dr. Kerkmeijer pointed out.
A majority of patients (84%) had high-risk disease, and two-thirds received hormonal therapy (usually in the adjuvant setting) with equal distribution across study arms, she reported.
With a median follow-up of 72 months, the 5-year rate of biochemical disease–free survival, the trial’s primary endpoint, was superior with the addition of the focal boost as compared with standard radiation therapy alone (92% vs. 85%; P < .001).
The boost also netted significantly better disease-free survival (P < .001).
The arms were similar on distant metastasis–free survival (P = .26), prostate cancer–specific survival (P = .49), and overall survival (P = .50), although longer follow-up is needed to fully assess these outcomes, Dr. Kerkmeijer noted.
The boost and standard therapy arms had much the same late grade 3 or higher genitourinary toxicity (5.6% vs. 3.5%; P = .22) and late grade 3 or higher gastrointestinal toxicity (1.4% vs. 1.4%; P = .99).
The arms were essentially identical on long-term patient-reported urinary symptoms, bowel symptoms, sexual activity, and sexual function, as measured with the EORTC QLQ-PR25 tool and detailed in a companion presentation (abstract OC-0315).
‘A standard option’ and next steps
“FLAME is the first phase 3 randomized controlled trial to show that focal boosting works and that biochemical recurrence was reduced at 5 years,” Dr. Kerkmeijer said. “We propose that the FLAME scheme can be considered as a standard option for patients with intermediate- but especially high-risk prostate cancer.”
“For patients, biochemical recurrence may have impact, as this causes additional follow-up and diagnostic exams, potential anxiety, and potential side effects of subsequent treatments,” she added. “Biochemical recurrences were reduced by almost half and at no additional cost and no additional toxicity by this FLAME isotoxic approach and by using conventional radiotherapy techniques.”
The next step is pairing the boost with ultra-hypofractionation, which requires highly accurate targeting, Dr. Kerkmeijer said. In fact, favorable early toxicity results of the subsequent Hypo-FLAME trial, which tested this strategy, were also reported at the congress (abstract OC-0209), and a trial taking the strategy even further, Hypo-FLAME 2.0, is ongoing.
“The FLAME trial’s results are probably true but may have been impacted by the use of hormonal therapy,” Anthony V. D’Amico, MD, PhD, of the Dana Farber Cancer Institute and Harvard Medical School, Boston, said in an interview.
Any imbalance in the use and duration of hormonal therapy, given that it can delay the time to prostate-specific antigen failure, could lead to overestimation or underestimation of the benefit of the focal boost, with respect to the primary endpoint of the study, he elaborated. Typical durations of this therapy range from 4 to 6 months for patients with intermediate-risk disease and from 18 to 36 months for patients with high-risk disease.
“So it’s important to know and to adjust not just for hormonal therapy use, but for duration between the two arms, stratified by risk group, in a multivariable regression analysis,” Dr. D’Amico concluded.
The FLAME trial was funded by the Dutch Cancer Society and Stand Up Against Cancer Belgium. Dr. Kerkmeijer and Dr. D’Amico disclosed having no conflicts of interest.
SOURCE: De Boer HCJ et al. ESTRO 2020. Abstract OC-0612.
The results were reported at the European Society for Radiology and Oncology 2020 Online Congress.
“We know that local recurrences most often occur at the location of the primary tumor or the dominant intraprostatic lesion, and we also know that biochemical disease–free survival improves with increasing dose to the whole prostate gland,” said principal investigator Linda G.W. Kerkmeijer, MD, PhD, of Radboud University Medical Center Nijmegen, the Netherlands.
However, “with whole-gland dose escalation, increased toxicity has been observed in both external-beam and brachytherapy trials,” she added.
FLAME trial details
A total of 571 patients took part in the FLAME trial, which is a collaboration of UMC Utrecht, the Netherlands Cancer Institute, University Hospitals Leuven, and Radboudumc.
The patients were randomized evenly to standard radiation therapy alone (77 Gy to the whole prostate in 35 fractions of 2.2 Gy) or with an integrated boost to the macroscopically visible tumor on multiparametric MRI (to reach a total dose of up to 95 Gy in 35 fractions of 2.7 Gy).
In treatment planning, the organs-at-risk constraints were prioritized over the focal boost dose, Dr. Kerkmeijer pointed out.
A majority of patients (84%) had high-risk disease, and two-thirds received hormonal therapy (usually in the adjuvant setting) with equal distribution across study arms, she reported.
With a median follow-up of 72 months, the 5-year rate of biochemical disease–free survival, the trial’s primary endpoint, was superior with the addition of the focal boost as compared with standard radiation therapy alone (92% vs. 85%; P < .001).
The boost also netted significantly better disease-free survival (P < .001).
The arms were similar on distant metastasis–free survival (P = .26), prostate cancer–specific survival (P = .49), and overall survival (P = .50), although longer follow-up is needed to fully assess these outcomes, Dr. Kerkmeijer noted.
The boost and standard therapy arms had much the same late grade 3 or higher genitourinary toxicity (5.6% vs. 3.5%; P = .22) and late grade 3 or higher gastrointestinal toxicity (1.4% vs. 1.4%; P = .99).
The arms were essentially identical on long-term patient-reported urinary symptoms, bowel symptoms, sexual activity, and sexual function, as measured with the EORTC QLQ-PR25 tool and detailed in a companion presentation (abstract OC-0315).
‘A standard option’ and next steps
“FLAME is the first phase 3 randomized controlled trial to show that focal boosting works and that biochemical recurrence was reduced at 5 years,” Dr. Kerkmeijer said. “We propose that the FLAME scheme can be considered as a standard option for patients with intermediate- but especially high-risk prostate cancer.”
“For patients, biochemical recurrence may have impact, as this causes additional follow-up and diagnostic exams, potential anxiety, and potential side effects of subsequent treatments,” she added. “Biochemical recurrences were reduced by almost half and at no additional cost and no additional toxicity by this FLAME isotoxic approach and by using conventional radiotherapy techniques.”
The next step is pairing the boost with ultra-hypofractionation, which requires highly accurate targeting, Dr. Kerkmeijer said. In fact, favorable early toxicity results of the subsequent Hypo-FLAME trial, which tested this strategy, were also reported at the congress (abstract OC-0209), and a trial taking the strategy even further, Hypo-FLAME 2.0, is ongoing.
“The FLAME trial’s results are probably true but may have been impacted by the use of hormonal therapy,” Anthony V. D’Amico, MD, PhD, of the Dana Farber Cancer Institute and Harvard Medical School, Boston, said in an interview.
Any imbalance in the use and duration of hormonal therapy, given that it can delay the time to prostate-specific antigen failure, could lead to overestimation or underestimation of the benefit of the focal boost, with respect to the primary endpoint of the study, he elaborated. Typical durations of this therapy range from 4 to 6 months for patients with intermediate-risk disease and from 18 to 36 months for patients with high-risk disease.
“So it’s important to know and to adjust not just for hormonal therapy use, but for duration between the two arms, stratified by risk group, in a multivariable regression analysis,” Dr. D’Amico concluded.
The FLAME trial was funded by the Dutch Cancer Society and Stand Up Against Cancer Belgium. Dr. Kerkmeijer and Dr. D’Amico disclosed having no conflicts of interest.
SOURCE: De Boer HCJ et al. ESTRO 2020. Abstract OC-0612.
FROM ESTRO 2020