ASTRO Annual Meeting 2011

MIAMI BEACH – Placing breast cancer patients in a prone rather than supine position during whole breast irradiation may significantly reduce their risk for secondary lung cancers, investigators reported at the annual meeting of the American Society for Radiation Oncology.

The total radiation dose that would be delivered to the corresponding (ipsilateral) lung of patients treated while they were lying face down was less than one-tenth of the dose delivered to that of patients treated while lying on their backs, said Dr. John Ng, senior radiation oncology resident at Columbia University Medical Center in New York.

The mean expected lifetime risk for radiation-associated secondary lung cancer is 1.99% in patients given whole breast irradiation with a prone technique, compared with 4.86% for patients treated with a supine technique, he reported. It was 3.87% for patients treated with a 3-D conformal partial breast irradiation technique, and 2.92% for patients treated with balloon brachytherapy (P less than .001 for all comparisons).

By way of comparison, the estimated expected background risk for lung cancer is about 1.5%, Dr. Ng and his colleagues wrote in a poster presentation.

"It’s documented that there is some excess relative risk of lung cancers after breast radiation treatment – I think everybody agrees with that. What people will disagree on is how significant this risk is, and that\'s what motivates us to do this study," Dr. Ng said in an interview.

The prone technique is, however, considerably more time consuming in terms of treatment planning and positioning of the patient, resulting in treatment sessions that are about twice as long as those for patients treated supinely (about 45 vs. 20 minutes, Dr. Ng said).

The investigators used a mathematical model to estimate the risk of both spontaneous and radiation-induced lung cancer risk in 25 women with early-stage breast cancer undergoing treatment planning with CT simulation for post-lumpectomy radiation therapy. Patients scheduled for whole breast irradiation were simulated in both the prone and the supine positions; those scheduled for partial breast irradiation were simulated in the supine position only.

The model encompassed standard dosing (50 Gy, delivered in 25 fractions), hypofractionation (42 Gy in 16 fractions), or standard external-beam accelerated partial breast irradiation (38.5 Gy in 10 fractions).

For each of the 15 patients treated in the prone technique, there would be significantly less radiation (54.2 cGy, on average) delivered to the lung than with the supine technique (646.5 cGy), balloon brachytherapy (291.0 cGy), or partial-breast irradiation (275.2 cGy; P less than .001 for all comparisons).

The relative risks for each technique and dosing schedule, compared with background risk, were 4.04 for supine standard fractionation, 3.98 for supine hypofractionation, 2.54 for balloon brachytherapy, 2.36 for 3D conformal accelerated partial-breast irradiation, and 1.56 for standard fractionation.

"The take-home point is that there is substantial risk of secondary lung malignancy from our standard technique. You can improve it with partial breast irradiation, but our study shows that the best results come from the prone technique," Dr. Ng said.

Dr. Phillip M. Devlin, chief of the division of brachytherapy at Dana-Farber Cancer Institute, Boston, commented that the study was interesting but complex, with the issue of prone vs. supine muddied by the inclusion of brachytherapy into the mix.

"In this small study, the hypothesis is generated that there would be less cancer caused by prone technique than by supine technique, and therefore a prospective analysis of this may be warranted. However, with these findings one might even ask whether it would be ethical to do the prospective study," said Dr. Devlin, who was not involved in the study.

He noted that the prone technique was originally developed to help women with more pendulous breasts tolerate whole breast irradiation better, with fewer side effects and improved cosmesis.

"Given the fact that we chose this technique for other end points, isn’t it interesting that if we also look at reasonable modeling done on a reasonably small data set, in the model the risk is lower with the prone technique, further endorsing what we’ve already found for a bigger and different reason. The cost to achieve this in terms of patient throughput is in play, but it is counterbalanced against the potential extra cost of treating either a local recurrence or a second malignant neoplasm," Dr. Devlin said.

The study was internally funded. Neither Dr. Ng nor Dr. Devlin had conflicts of interest to disclose.

MIAMI BEACH – Placing breast cancer patients in a prone rather than supine position during whole breast irradiation may significantly reduce their risk for secondary lung cancers, investigators reported at the annual meeting of the American Society for Radiation Oncology.

The total radiation dose that would be delivered to the corresponding (ipsilateral) lung of patients treated while they were lying face down was less than one-tenth of the dose delivered to that of patients treated while lying on their backs, said Dr. John Ng, senior radiation oncology resident at Columbia University Medical Center in New York.

The mean expected lifetime risk for radiation-associated secondary lung cancer is 1.99% in patients given whole breast irradiation with a prone technique, compared with 4.86% for patients treated with a supine technique, he reported. It was 3.87% for patients treated with a 3-D conformal partial breast irradiation technique, and 2.92% for patients treated with balloon brachytherapy (P less than .001 for all comparisons).

By way of comparison, the estimated expected background risk for lung cancer is about 1.5%, Dr. Ng and his colleagues wrote in a poster presentation.

"It’s documented that there is some excess relative risk of lung cancers after breast radiation treatment – I think everybody agrees with that. What people will disagree on is how significant this risk is, and that\'s what motivates us to do this study," Dr. Ng said in an interview.

The prone technique is, however, considerably more time consuming in terms of treatment planning and positioning of the patient, resulting in treatment sessions that are about twice as long as those for patients treated supinely (about 45 vs. 20 minutes, Dr. Ng said).

The investigators used a mathematical model to estimate the risk of both spontaneous and radiation-induced lung cancer risk in 25 women with early-stage breast cancer undergoing treatment planning with CT simulation for post-lumpectomy radiation therapy. Patients scheduled for whole breast irradiation were simulated in both the prone and the supine positions; those scheduled for partial breast irradiation were simulated in the supine position only.

The model encompassed standard dosing (50 Gy, delivered in 25 fractions), hypofractionation (42 Gy in 16 fractions), or standard external-beam accelerated partial breast irradiation (38.5 Gy in 10 fractions).

For each of the 15 patients treated in the prone technique, there would be significantly less radiation (54.2 cGy, on average) delivered to the lung than with the supine technique (646.5 cGy), balloon brachytherapy (291.0 cGy), or partial-breast irradiation (275.2 cGy; P less than .001 for all comparisons).

The relative risks for each technique and dosing schedule, compared with background risk, were 4.04 for supine standard fractionation, 3.98 for supine hypofractionation, 2.54 for balloon brachytherapy, 2.36 for 3D conformal accelerated partial-breast irradiation, and 1.56 for standard fractionation.

"The take-home point is that there is substantial risk of secondary lung malignancy from our standard technique. You can improve it with partial breast irradiation, but our study shows that the best results come from the prone technique," Dr. Ng said.

Dr. Phillip M. Devlin, chief of the division of brachytherapy at Dana-Farber Cancer Institute, Boston, commented that the study was interesting but complex, with the issue of prone vs. supine muddied by the inclusion of brachytherapy into the mix.

"In this small study, the hypothesis is generated that there would be less cancer caused by prone technique than by supine technique, and therefore a prospective analysis of this may be warranted. However, with these findings one might even ask whether it would be ethical to do the prospective study," said Dr. Devlin, who was not involved in the study.

He noted that the prone technique was originally developed to help women with more pendulous breasts tolerate whole breast irradiation better, with fewer side effects and improved cosmesis.

"Given the fact that we chose this technique for other end points, isn’t it interesting that if we also look at reasonable modeling done on a reasonably small data set, in the model the risk is lower with the prone technique, further endorsing what we’ve already found for a bigger and different reason. The cost to achieve this in terms of patient throughput is in play, but it is counterbalanced against the potential extra cost of treating either a local recurrence or a second malignant neoplasm," Dr. Devlin said.

The study was internally funded. Neither Dr. Ng nor Dr. Devlin had conflicts of interest to disclose.

MIAMI BEACH – Placing breast cancer patients in a prone rather than supine position during whole breast irradiation may significantly reduce their risk for secondary lung cancers, investigators reported at the annual meeting of the American Society for Radiation Oncology.

The total radiation dose that would be delivered to the corresponding (ipsilateral) lung of patients treated while they were lying face down was less than one-tenth of the dose delivered to that of patients treated while lying on their backs, said Dr. John Ng, senior radiation oncology resident at Columbia University Medical Center in New York.

The mean expected lifetime risk for radiation-associated secondary lung cancer is 1.99% in patients given whole breast irradiation with a prone technique, compared with 4.86% for patients treated with a supine technique, he reported. It was 3.87% for patients treated with a 3-D conformal partial breast irradiation technique, and 2.92% for patients treated with balloon brachytherapy (P less than .001 for all comparisons).

By way of comparison, the estimated expected background risk for lung cancer is about 1.5%, Dr. Ng and his colleagues wrote in a poster presentation.

"It’s documented that there is some excess relative risk of lung cancers after breast radiation treatment – I think everybody agrees with that. What people will disagree on is how significant this risk is, and that\'s what motivates us to do this study," Dr. Ng said in an interview.

The prone technique is, however, considerably more time consuming in terms of treatment planning and positioning of the patient, resulting in treatment sessions that are about twice as long as those for patients treated supinely (about 45 vs. 20 minutes, Dr. Ng said).

The investigators used a mathematical model to estimate the risk of both spontaneous and radiation-induced lung cancer risk in 25 women with early-stage breast cancer undergoing treatment planning with CT simulation for post-lumpectomy radiation therapy. Patients scheduled for whole breast irradiation were simulated in both the prone and the supine positions; those scheduled for partial breast irradiation were simulated in the supine position only.

The model encompassed standard dosing (50 Gy, delivered in 25 fractions), hypofractionation (42 Gy in 16 fractions), or standard external-beam accelerated partial breast irradiation (38.5 Gy in 10 fractions).

For each of the 15 patients treated in the prone technique, there would be significantly less radiation (54.2 cGy, on average) delivered to the lung than with the supine technique (646.5 cGy), balloon brachytherapy (291.0 cGy), or partial-breast irradiation (275.2 cGy; P less than .001 for all comparisons).

The relative risks for each technique and dosing schedule, compared with background risk, were 4.04 for supine standard fractionation, 3.98 for supine hypofractionation, 2.54 for balloon brachytherapy, 2.36 for 3D conformal accelerated partial-breast irradiation, and 1.56 for standard fractionation.

"The take-home point is that there is substantial risk of secondary lung malignancy from our standard technique. You can improve it with partial breast irradiation, but our study shows that the best results come from the prone technique," Dr. Ng said.

Dr. Phillip M. Devlin, chief of the division of brachytherapy at Dana-Farber Cancer Institute, Boston, commented that the study was interesting but complex, with the issue of prone vs. supine muddied by the inclusion of brachytherapy into the mix.

"In this small study, the hypothesis is generated that there would be less cancer caused by prone technique than by supine technique, and therefore a prospective analysis of this may be warranted. However, with these findings one might even ask whether it would be ethical to do the prospective study," said Dr. Devlin, who was not involved in the study.

He noted that the prone technique was originally developed to help women with more pendulous breasts tolerate whole breast irradiation better, with fewer side effects and improved cosmesis.

"Given the fact that we chose this technique for other end points, isn’t it interesting that if we also look at reasonable modeling done on a reasonably small data set, in the model the risk is lower with the prone technique, further endorsing what we’ve already found for a bigger and different reason. The cost to achieve this in terms of patient throughput is in play, but it is counterbalanced against the potential extra cost of treating either a local recurrence or a second malignant neoplasm," Dr. Devlin said.

The study was internally funded. Neither Dr. Ng nor Dr. Devlin had conflicts of interest to disclose.

A shorter, more intense course of radiotherapy was as effective as conventional intensity-modulated radiation therapy for the treatment of intermediate- to high-risk prostate cancer in a randomized, controlled, phase III dose-escalation trial involving 303 patients.

At 5 years of follow-up, outcomes were similar whether men received hypofractionated intensity-modulated radiation therapy (hIMRT) or conventional IMRT (cIMRT), Dr. Alan Pollack reported during a press conference sponsored by the American Society for Radiation Oncology (ASTRO).

The hypofractionated approach – which compresses the standard prostate cancer treatment schedule by delivering a higher dose of radiation for fewer days – shortened treatment duration to 5.1 weeks without increasing long-term toxicity, he said. Radiotherapy lasted 7.5 weeks with conventional IMRT.

The findings will be presented on Oct. 3 at the ASTRO annual meeting in Miami Beach.

The approach is based on extensive data indicating that hypofractionation confers radiobiological advantages, according to Dr. Pollack, professor and chair of radiation oncology at the University of Miami.

The 151 patients who were randomized to receive hIMRT (70.2 Gy in 27.2 Gy fractions) had a 5-year cumulative incidence rate of biochemical failure of 13.9%, compared with 14.4% in the 152 patients randomized to receive cIMRT (76 Gy in 2.0 Gy fractions).

Clinical failure rates (defined as local/regional failure or distant metastases) were 1.3% in the hIMRT group and 1.0% in the cIMRT groups, Dr. Pollack said. The rates of "any failure" were 15.3% and 15.4% in the groups, respectively.

Dr. Pollack and his colleagues had hypothesized correctly that hIMRT would have a failure rate in the 15% range, but they also hypothesized that it would be superior to cIMRT. Conventional IMRT performed better than expected, he said.

As for side effects, grade 2 or higher genitourinary toxicities occurred in 13.8% and 8.9% of patients in the hIMRT and cIMRT groups, respectively (P = 0.2), and gastrointestinal toxicities occurred in 5.9% and 4.1% of the patients in the groups, respectively (P = 0.5).

More bladder control problems in the men who had received hIMRT accounted for the difference in genitourinary effects, as the frequency of unsatisfactory erections in the groups were similar. However, the rates of persistent urinary symptoms were less than 10% in both groups, which is still less than the 15% typically reported in the literature, Dr. Pollack noted.

"We did find that in general, the side effects were low," said Dr. Pollack, who described HIMRT as "a more sophisticated way of administering radiation."

CIMRT and HIMRT patients, all of whom were treated in 2002-2006, were similar in regard to T categories, Gleason scores, pretreatment initial prostate-specific antigen levels, and use of – and length of – androgen deprivation therapy. Biochemical failure was assessed using the Phoenix definition (PSA nadir + 2 ng/mL), and clinical failure was defined as either locoregional failure or distant metastases, he noted.

"Hypofractionation for prostate cancer does show promise," Dr. Pollack said, noting that work is ongoing to identify the limits and best approaches for applying hypofractionation while limiting side effects – particularly urinary side effects, which tend to cause the greatest amount of problems following most types of treatment for prostate cancer.

The approach has not been broadly adopted, because long-term follow-up and greater understanding of the risks are needed, but Dr. Michael L. Steinberg, professor and chair of radiation oncology at the University of California, Los Angeles, and ASTRO’s president-elect, agreed that hypofractionation represents an emerging trend in the treatment of prostate and other cancers.

It will also likely represent a cost benefit, Dr. Pollack added. The current study did not include a cost-benefit analysis, but the shorter treatment duration should translate into significant savings both in up-front costs and in terms of time away from work, he said.

Dr. Pollack had no relevant disclosures. Dr. Steinberg serves in a leadership position on the American College of Radiology Economics Committee.

A shorter, more intense course of radiotherapy was as effective as conventional intensity-modulated radiation therapy for the treatment of intermediate- to high-risk prostate cancer in a randomized, controlled, phase III dose-escalation trial involving 303 patients.

At 5 years of follow-up, outcomes were similar whether men received hypofractionated intensity-modulated radiation therapy (hIMRT) or conventional IMRT (cIMRT), Dr. Alan Pollack reported during a press conference sponsored by the American Society for Radiation Oncology (ASTRO).

The hypofractionated approach – which compresses the standard prostate cancer treatment schedule by delivering a higher dose of radiation for fewer days – shortened treatment duration to 5.1 weeks without increasing long-term toxicity, he said. Radiotherapy lasted 7.5 weeks with conventional IMRT.

The findings will be presented on Oct. 3 at the ASTRO annual meeting in Miami Beach.

The approach is based on extensive data indicating that hypofractionation confers radiobiological advantages, according to Dr. Pollack, professor and chair of radiation oncology at the University of Miami.

The 151 patients who were randomized to receive hIMRT (70.2 Gy in 27.2 Gy fractions) had a 5-year cumulative incidence rate of biochemical failure of 13.9%, compared with 14.4% in the 152 patients randomized to receive cIMRT (76 Gy in 2.0 Gy fractions).

Clinical failure rates (defined as local/regional failure or distant metastases) were 1.3% in the hIMRT group and 1.0% in the cIMRT groups, Dr. Pollack said. The rates of "any failure" were 15.3% and 15.4% in the groups, respectively.

Dr. Pollack and his colleagues had hypothesized correctly that hIMRT would have a failure rate in the 15% range, but they also hypothesized that it would be superior to cIMRT. Conventional IMRT performed better than expected, he said.

As for side effects, grade 2 or higher genitourinary toxicities occurred in 13.8% and 8.9% of patients in the hIMRT and cIMRT groups, respectively (P = 0.2), and gastrointestinal toxicities occurred in 5.9% and 4.1% of the patients in the groups, respectively (P = 0.5).

More bladder control problems in the men who had received hIMRT accounted for the difference in genitourinary effects, as the frequency of unsatisfactory erections in the groups were similar. However, the rates of persistent urinary symptoms were less than 10% in both groups, which is still less than the 15% typically reported in the literature, Dr. Pollack noted.

"We did find that in general, the side effects were low," said Dr. Pollack, who described HIMRT as "a more sophisticated way of administering radiation."

CIMRT and HIMRT patients, all of whom were treated in 2002-2006, were similar in regard to T categories, Gleason scores, pretreatment initial prostate-specific antigen levels, and use of – and length of – androgen deprivation therapy. Biochemical failure was assessed using the Phoenix definition (PSA nadir + 2 ng/mL), and clinical failure was defined as either locoregional failure or distant metastases, he noted.

"Hypofractionation for prostate cancer does show promise," Dr. Pollack said, noting that work is ongoing to identify the limits and best approaches for applying hypofractionation while limiting side effects – particularly urinary side effects, which tend to cause the greatest amount of problems following most types of treatment for prostate cancer.

The approach has not been broadly adopted, because long-term follow-up and greater understanding of the risks are needed, but Dr. Michael L. Steinberg, professor and chair of radiation oncology at the University of California, Los Angeles, and ASTRO’s president-elect, agreed that hypofractionation represents an emerging trend in the treatment of prostate and other cancers.

It will also likely represent a cost benefit, Dr. Pollack added. The current study did not include a cost-benefit analysis, but the shorter treatment duration should translate into significant savings both in up-front costs and in terms of time away from work, he said.

Dr. Pollack had no relevant disclosures. Dr. Steinberg serves in a leadership position on the American College of Radiology Economics Committee.

A shorter, more intense course of radiotherapy was as effective as conventional intensity-modulated radiation therapy for the treatment of intermediate- to high-risk prostate cancer in a randomized, controlled, phase III dose-escalation trial involving 303 patients.

At 5 years of follow-up, outcomes were similar whether men received hypofractionated intensity-modulated radiation therapy (hIMRT) or conventional IMRT (cIMRT), Dr. Alan Pollack reported during a press conference sponsored by the American Society for Radiation Oncology (ASTRO).

The hypofractionated approach – which compresses the standard prostate cancer treatment schedule by delivering a higher dose of radiation for fewer days – shortened treatment duration to 5.1 weeks without increasing long-term toxicity, he said. Radiotherapy lasted 7.5 weeks with conventional IMRT.

The findings will be presented on Oct. 3 at the ASTRO annual meeting in Miami Beach.

The approach is based on extensive data indicating that hypofractionation confers radiobiological advantages, according to Dr. Pollack, professor and chair of radiation oncology at the University of Miami.

The 151 patients who were randomized to receive hIMRT (70.2 Gy in 27.2 Gy fractions) had a 5-year cumulative incidence rate of biochemical failure of 13.9%, compared with 14.4% in the 152 patients randomized to receive cIMRT (76 Gy in 2.0 Gy fractions).

Clinical failure rates (defined as local/regional failure or distant metastases) were 1.3% in the hIMRT group and 1.0% in the cIMRT groups, Dr. Pollack said. The rates of "any failure" were 15.3% and 15.4% in the groups, respectively.

Dr. Pollack and his colleagues had hypothesized correctly that hIMRT would have a failure rate in the 15% range, but they also hypothesized that it would be superior to cIMRT. Conventional IMRT performed better than expected, he said.

As for side effects, grade 2 or higher genitourinary toxicities occurred in 13.8% and 8.9% of patients in the hIMRT and cIMRT groups, respectively (P = 0.2), and gastrointestinal toxicities occurred in 5.9% and 4.1% of the patients in the groups, respectively (P = 0.5).

More bladder control problems in the men who had received hIMRT accounted for the difference in genitourinary effects, as the frequency of unsatisfactory erections in the groups were similar. However, the rates of persistent urinary symptoms were less than 10% in both groups, which is still less than the 15% typically reported in the literature, Dr. Pollack noted.

"We did find that in general, the side effects were low," said Dr. Pollack, who described HIMRT as "a more sophisticated way of administering radiation."

CIMRT and HIMRT patients, all of whom were treated in 2002-2006, were similar in regard to T categories, Gleason scores, pretreatment initial prostate-specific antigen levels, and use of – and length of – androgen deprivation therapy. Biochemical failure was assessed using the Phoenix definition (PSA nadir + 2 ng/mL), and clinical failure was defined as either locoregional failure or distant metastases, he noted.

"Hypofractionation for prostate cancer does show promise," Dr. Pollack said, noting that work is ongoing to identify the limits and best approaches for applying hypofractionation while limiting side effects – particularly urinary side effects, which tend to cause the greatest amount of problems following most types of treatment for prostate cancer.

The approach has not been broadly adopted, because long-term follow-up and greater understanding of the risks are needed, but Dr. Michael L. Steinberg, professor and chair of radiation oncology at the University of California, Los Angeles, and ASTRO’s president-elect, agreed that hypofractionation represents an emerging trend in the treatment of prostate and other cancers.

It will also likely represent a cost benefit, Dr. Pollack added. The current study did not include a cost-benefit analysis, but the shorter treatment duration should translate into significant savings both in up-front costs and in terms of time away from work, he said.

Dr. Pollack had no relevant disclosures. Dr. Steinberg serves in a leadership position on the American College of Radiology Economics Committee.