Radiotherapy Comparison Favors IMRT for Prostate Cancer

A comparison of three radiotherapies for nonmetastatic prostate cancer supports the widespread use of intensity-modulated radiation treatment, though it leads to more erectile dysfunction than occurs with conformal radiation therapy, according to a report published April 17 in JAMA.

Proton therapy, the newest and most expensive option for these patients, fared poorly in the comparison. It had more GI side effects than intensity-modulated radiation treatment (IMRT) but was not more effective, investigators found.

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"Overall, our results do not clearly demonstrate a clinical benefit to support the recent increase in proton therapy use for prostate cancer," wrote Dr. Nathan C. Sheets of the University of North Carolina, Chapel Hill, and his coauthors (JAMA 2012;307:1611-20).

Dr. Sheets presented the study in February at the Genitourinary Cancers Symposium sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology, and the Society of Urologic Oncology.

This study and another comparing external beam radiation therapy, prostatectomy, and brachytherapy provoked discussion of whether outcomes justified the costs of newer technologies.

IMRT, a more expensive, more targeted form of radiotherapy, has gradually replaced conformal radiation therapy (CRT), with its use surging from 0.15% in 2000 to 95.9% in 2008, according to Dr. Sheets and his coauthors. In turn, IMRT is facing increasing competition from proton therapy, which they describe as "a high-profile, high-cost prostate cancer treatment."

"Since 2007, multiple proton facilities have been built, and direct-to-consumer advertising is likely to lead to a substantial increase in use," they observed, noting that comparative effectiveness research on these treatments is lacking.

To that end, the investigators used a propensity scoring method to analyze data on 12,976 men who were identified in the Surveillance, Epidemiology, and End Results program registry and had been treated between 2002 and 2006: 6,666 with IMRT and 6,310 with CRT.

The investigators found that men who received IMRT were about 20% less likely to receive additional cancer therapy, with an absolute risk of 2.5 vs. 3.1 per 100 person years (P less than .001).

The IMRT cohort also was significantly less likely to be diagnosed with GI morbidities (absolute risk, 13.4 vs. 14.7 per 100 person-years) and hip fractures (absolute risk, 0.8 vs. 1.0 per 100 person-years), but more likely to be diagnosed with erectile dysfunction than those who received CRT (absolute risk, 5.9 vs. 5.3 per 100 person-years).

In a smaller propensity-score matched comparison of 1,368 men treated with IMRT or proton therapy, the investigators found less GI morbidity with IMRT (absolute risk, 12.2 vs. 17.8 per 100 person-years) and no difference in efficacy.

"This population-based study suggests that IMRT may be associated with improved disease control without compromising morbidity compared with conformal radiation therapy, although proton therapy does not appear to provide additional benefit," they concluded.

The research was supported by the Agency for Healthcare Research and Quality. A grant from the National Institute of Nursing Research enabled publication. Two coauthors reported relationship with pharmaceutical companies.

A comparison of three radiotherapies for nonmetastatic prostate cancer supports the widespread use of intensity-modulated radiation treatment, though it leads to more erectile dysfunction than occurs with conformal radiation therapy, according to a report published April 17 in JAMA.

Proton therapy, the newest and most expensive option for these patients, fared poorly in the comparison. It had more GI side effects than intensity-modulated radiation treatment (IMRT) but was not more effective, investigators found.

Related Video >>

"Overall, our results do not clearly demonstrate a clinical benefit to support the recent increase in proton therapy use for prostate cancer," wrote Dr. Nathan C. Sheets of the University of North Carolina, Chapel Hill, and his coauthors (JAMA 2012;307:1611-20).

Dr. Sheets presented the study in February at the Genitourinary Cancers Symposium sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology, and the Society of Urologic Oncology.

This study and another comparing external beam radiation therapy, prostatectomy, and brachytherapy provoked discussion of whether outcomes justified the costs of newer technologies.

IMRT, a more expensive, more targeted form of radiotherapy, has gradually replaced conformal radiation therapy (CRT), with its use surging from 0.15% in 2000 to 95.9% in 2008, according to Dr. Sheets and his coauthors. In turn, IMRT is facing increasing competition from proton therapy, which they describe as "a high-profile, high-cost prostate cancer treatment."

"Since 2007, multiple proton facilities have been built, and direct-to-consumer advertising is likely to lead to a substantial increase in use," they observed, noting that comparative effectiveness research on these treatments is lacking.

To that end, the investigators used a propensity scoring method to analyze data on 12,976 men who were identified in the Surveillance, Epidemiology, and End Results program registry and had been treated between 2002 and 2006: 6,666 with IMRT and 6,310 with CRT.

The investigators found that men who received IMRT were about 20% less likely to receive additional cancer therapy, with an absolute risk of 2.5 vs. 3.1 per 100 person years (P less than .001).

The IMRT cohort also was significantly less likely to be diagnosed with GI morbidities (absolute risk, 13.4 vs. 14.7 per 100 person-years) and hip fractures (absolute risk, 0.8 vs. 1.0 per 100 person-years), but more likely to be diagnosed with erectile dysfunction than those who received CRT (absolute risk, 5.9 vs. 5.3 per 100 person-years).

In a smaller propensity-score matched comparison of 1,368 men treated with IMRT or proton therapy, the investigators found less GI morbidity with IMRT (absolute risk, 12.2 vs. 17.8 per 100 person-years) and no difference in efficacy.

"This population-based study suggests that IMRT may be associated with improved disease control without compromising morbidity compared with conformal radiation therapy, although proton therapy does not appear to provide additional benefit," they concluded.

The research was supported by the Agency for Healthcare Research and Quality. A grant from the National Institute of Nursing Research enabled publication. Two coauthors reported relationship with pharmaceutical companies.

A comparison of three radiotherapies for nonmetastatic prostate cancer supports the widespread use of intensity-modulated radiation treatment, though it leads to more erectile dysfunction than occurs with conformal radiation therapy, according to a report published April 17 in JAMA.

Proton therapy, the newest and most expensive option for these patients, fared poorly in the comparison. It had more GI side effects than intensity-modulated radiation treatment (IMRT) but was not more effective, investigators found.

Related Video >>

"Overall, our results do not clearly demonstrate a clinical benefit to support the recent increase in proton therapy use for prostate cancer," wrote Dr. Nathan C. Sheets of the University of North Carolina, Chapel Hill, and his coauthors (JAMA 2012;307:1611-20).

Dr. Sheets presented the study in February at the Genitourinary Cancers Symposium sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology, and the Society of Urologic Oncology.

This study and another comparing external beam radiation therapy, prostatectomy, and brachytherapy provoked discussion of whether outcomes justified the costs of newer technologies.

IMRT, a more expensive, more targeted form of radiotherapy, has gradually replaced conformal radiation therapy (CRT), with its use surging from 0.15% in 2000 to 95.9% in 2008, according to Dr. Sheets and his coauthors. In turn, IMRT is facing increasing competition from proton therapy, which they describe as "a high-profile, high-cost prostate cancer treatment."

"Since 2007, multiple proton facilities have been built, and direct-to-consumer advertising is likely to lead to a substantial increase in use," they observed, noting that comparative effectiveness research on these treatments is lacking.

To that end, the investigators used a propensity scoring method to analyze data on 12,976 men who were identified in the Surveillance, Epidemiology, and End Results program registry and had been treated between 2002 and 2006: 6,666 with IMRT and 6,310 with CRT.

The investigators found that men who received IMRT were about 20% less likely to receive additional cancer therapy, with an absolute risk of 2.5 vs. 3.1 per 100 person years (P less than .001).

The IMRT cohort also was significantly less likely to be diagnosed with GI morbidities (absolute risk, 13.4 vs. 14.7 per 100 person-years) and hip fractures (absolute risk, 0.8 vs. 1.0 per 100 person-years), but more likely to be diagnosed with erectile dysfunction than those who received CRT (absolute risk, 5.9 vs. 5.3 per 100 person-years).

In a smaller propensity-score matched comparison of 1,368 men treated with IMRT or proton therapy, the investigators found less GI morbidity with IMRT (absolute risk, 12.2 vs. 17.8 per 100 person-years) and no difference in efficacy.

"This population-based study suggests that IMRT may be associated with improved disease control without compromising morbidity compared with conformal radiation therapy, although proton therapy does not appear to provide additional benefit," they concluded.

The research was supported by the Agency for Healthcare Research and Quality. A grant from the National Institute of Nursing Research enabled publication. Two coauthors reported relationship with pharmaceutical companies.