Only Short-Term Advantage for Protons in Prostate Cancer

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Only Short-Term Advantage for Protons in Prostate Cancer

BOSTON – Men who receive proton beam radiotherapy for prostate cancer have modestly better bowel function in the short term than do those who receive conformal or intensity-modulated radiation, but the effect is transient, investigators found.

At 2-3 months follow-up, patients treated with proton beam therapy (PBT) reported minimal decrements in bowel function, compared with patients treated with either 3D conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT), who reported modest yet clinically meaningful decrements in bowel function, lead author Dr. Phillip J. Gray reported at the annual meeting of the American Society for Radiation Oncology.

Neil Osterweil/IMNG Medical Media
Dr. Phillip J. Gray

All three patient groups also had significantly lower urinary quality-of-life (QoL) scores at early follow-up compared with baseline, but these changes were considered clinically meaningful only for IMRT, said Dr. Gray, a resident in the Harvard Radiation Oncology program in Boston.

"Though significant, these differences appear transient, with all three groups showing clinically meaningful decrements in bowel quality of life at 2 years following the start of treatment, and minimally lingering urinary symptoms," he said.

The retrospective study looked at three cohorts of men treated with the different modalities: 153 treated with IMRT monotherapy in the PROST-QA consortium, 94 patients treated with PBT at Massachusetts General Hospital (MGH), and 123 treated with 3D-CRT at MGH and other Harvard-affiliated hospitals.

Patients treated with IMRT and PBT were evaluated with the Expanded Prostate Cancer Index Composite (EPIC) instrument; patients treated with 3D-CRT were assessed using the Prostate Cancer Symptoms Index (PCSI); PCSI scores were inverted to match those of the EPIC scale.

Treatment dose ranges were 75.6-79.2 Gy for IMRT, 74-82 Gy relative biological effectiveness values for PBT, and 66.4-79.2 Gy for 3D-CRT.

Mean patient-reported bowel QoL scores in the immediate post-treatment period were 93.3 on a scale of 0-100 for PBT, 78.5 for IMRT, and 88.2 for 3D-CRT (P vs. PBT less than .001 for both comparisons). The differences from baseline in IMRT and 3D-CRT, but not in PBT, were considered clinically significant.

At 24 months, mean respective bowel QoL scores were 91.8, 87.6, and 90.2, respectively, with clinically significant differences between PBT and the other two modalities.

 

 

Dr. Gray acknowledged that the retrospective nature of the study and the use of different scoring instruments muddy the comparison waters. He noted that things may become clearer when the results of a recently launched randomized trial comparing PBT and IMRT become available. The study will look at 6-month efficacy outcomes, cost effectiveness, and toxicities at 2 years, and survival and other end points out to 10 years.

Protons Are a Costly Choice

Although the relative long-term benefits of PBT for prostate cancer may not be known for several years, one thing is sure: PBT is about 70% more expensive than IMRT, said Dr. James Yu, a radiation oncologist at Yale University in New Haven, Conn.

Neil Osterweil/IMNG Medical Media
Dr. James Yu

Dr. Yu and colleagues looked at data on patients who received IMRT or PBT as primary therapy for prostate cancer in the Medicare Chronic Condition Data Warehouse, a national database that captures 100% of Medicare fee-for-service claims for patients with specific chronic conditions.

They found that the median interquartile range amount that Medicare reimbursed for PBT was $32,428 vs. $18,575 for IMRT.

In early follow-up (0-6 months) genitourinary complications were significantly lower among 421 patients with who had received PBT than among 842 patients who received IMRT (5.9% vs. 9.5%; odds ratio 0.60; P = .03). Neither gastrointestinal nor other complications were significantly different, however, and at 12 months follow-up there were no significant differences between treatment types, Dr. Yu noted.

"A continued longitudinal study of the comparative effectiveness of proton radiation is needed, and we also believe that further study is needed before widespread application of proton radiation can be justified," he said.

PBT Benefit Proven in Other Cancers

A radiation oncologist who was not involved in the study commented that in the absence of evidence of a therapeutic benefit for PBT in prostate cancer over other modalities, proton therapy may better be reserved for the treatment of other cancers.

"If you have a resource that’s limited, you want to use it where you know there’s a benefit," said Dr, Jeffrey Bradley, professor of radiation oncology at Washington University in St. Louis.

His center is building a single-vault proton-beam facility that is expected to open in the summer of 2013. Dr. Bradley said that although they will likely treat patients with prostate cancer, he envisions the main role of the center to be treatment of pediatric and adult tumors of the central nervous system, sarcomas, ocular neoplasms, and other conditions where the benefits of PBT are better documented.

Dr Gray, Dr. Yu, and Dr. Bradley each reported no conflicts of interest.

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BOSTON – Men who receive proton beam radiotherapy for prostate cancer have modestly better bowel function in the short term than do those who receive conformal or intensity-modulated radiation, but the effect is transient, investigators found.

At 2-3 months follow-up, patients treated with proton beam therapy (PBT) reported minimal decrements in bowel function, compared with patients treated with either 3D conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT), who reported modest yet clinically meaningful decrements in bowel function, lead author Dr. Phillip J. Gray reported at the annual meeting of the American Society for Radiation Oncology.

Neil Osterweil/IMNG Medical Media
Dr. Phillip J. Gray

All three patient groups also had significantly lower urinary quality-of-life (QoL) scores at early follow-up compared with baseline, but these changes were considered clinically meaningful only for IMRT, said Dr. Gray, a resident in the Harvard Radiation Oncology program in Boston.

"Though significant, these differences appear transient, with all three groups showing clinically meaningful decrements in bowel quality of life at 2 years following the start of treatment, and minimally lingering urinary symptoms," he said.

The retrospective study looked at three cohorts of men treated with the different modalities: 153 treated with IMRT monotherapy in the PROST-QA consortium, 94 patients treated with PBT at Massachusetts General Hospital (MGH), and 123 treated with 3D-CRT at MGH and other Harvard-affiliated hospitals.

Patients treated with IMRT and PBT were evaluated with the Expanded Prostate Cancer Index Composite (EPIC) instrument; patients treated with 3D-CRT were assessed using the Prostate Cancer Symptoms Index (PCSI); PCSI scores were inverted to match those of the EPIC scale.

Treatment dose ranges were 75.6-79.2 Gy for IMRT, 74-82 Gy relative biological effectiveness values for PBT, and 66.4-79.2 Gy for 3D-CRT.

Mean patient-reported bowel QoL scores in the immediate post-treatment period were 93.3 on a scale of 0-100 for PBT, 78.5 for IMRT, and 88.2 for 3D-CRT (P vs. PBT less than .001 for both comparisons). The differences from baseline in IMRT and 3D-CRT, but not in PBT, were considered clinically significant.

At 24 months, mean respective bowel QoL scores were 91.8, 87.6, and 90.2, respectively, with clinically significant differences between PBT and the other two modalities.

 

 

Dr. Gray acknowledged that the retrospective nature of the study and the use of different scoring instruments muddy the comparison waters. He noted that things may become clearer when the results of a recently launched randomized trial comparing PBT and IMRT become available. The study will look at 6-month efficacy outcomes, cost effectiveness, and toxicities at 2 years, and survival and other end points out to 10 years.

Protons Are a Costly Choice

Although the relative long-term benefits of PBT for prostate cancer may not be known for several years, one thing is sure: PBT is about 70% more expensive than IMRT, said Dr. James Yu, a radiation oncologist at Yale University in New Haven, Conn.

Neil Osterweil/IMNG Medical Media
Dr. James Yu

Dr. Yu and colleagues looked at data on patients who received IMRT or PBT as primary therapy for prostate cancer in the Medicare Chronic Condition Data Warehouse, a national database that captures 100% of Medicare fee-for-service claims for patients with specific chronic conditions.

They found that the median interquartile range amount that Medicare reimbursed for PBT was $32,428 vs. $18,575 for IMRT.

In early follow-up (0-6 months) genitourinary complications were significantly lower among 421 patients with who had received PBT than among 842 patients who received IMRT (5.9% vs. 9.5%; odds ratio 0.60; P = .03). Neither gastrointestinal nor other complications were significantly different, however, and at 12 months follow-up there were no significant differences between treatment types, Dr. Yu noted.

"A continued longitudinal study of the comparative effectiveness of proton radiation is needed, and we also believe that further study is needed before widespread application of proton radiation can be justified," he said.

PBT Benefit Proven in Other Cancers

A radiation oncologist who was not involved in the study commented that in the absence of evidence of a therapeutic benefit for PBT in prostate cancer over other modalities, proton therapy may better be reserved for the treatment of other cancers.

"If you have a resource that’s limited, you want to use it where you know there’s a benefit," said Dr, Jeffrey Bradley, professor of radiation oncology at Washington University in St. Louis.

His center is building a single-vault proton-beam facility that is expected to open in the summer of 2013. Dr. Bradley said that although they will likely treat patients with prostate cancer, he envisions the main role of the center to be treatment of pediatric and adult tumors of the central nervous system, sarcomas, ocular neoplasms, and other conditions where the benefits of PBT are better documented.

Dr Gray, Dr. Yu, and Dr. Bradley each reported no conflicts of interest.

BOSTON – Men who receive proton beam radiotherapy for prostate cancer have modestly better bowel function in the short term than do those who receive conformal or intensity-modulated radiation, but the effect is transient, investigators found.

At 2-3 months follow-up, patients treated with proton beam therapy (PBT) reported minimal decrements in bowel function, compared with patients treated with either 3D conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT), who reported modest yet clinically meaningful decrements in bowel function, lead author Dr. Phillip J. Gray reported at the annual meeting of the American Society for Radiation Oncology.

Neil Osterweil/IMNG Medical Media
Dr. Phillip J. Gray

All three patient groups also had significantly lower urinary quality-of-life (QoL) scores at early follow-up compared with baseline, but these changes were considered clinically meaningful only for IMRT, said Dr. Gray, a resident in the Harvard Radiation Oncology program in Boston.

"Though significant, these differences appear transient, with all three groups showing clinically meaningful decrements in bowel quality of life at 2 years following the start of treatment, and minimally lingering urinary symptoms," he said.

The retrospective study looked at three cohorts of men treated with the different modalities: 153 treated with IMRT monotherapy in the PROST-QA consortium, 94 patients treated with PBT at Massachusetts General Hospital (MGH), and 123 treated with 3D-CRT at MGH and other Harvard-affiliated hospitals.

Patients treated with IMRT and PBT were evaluated with the Expanded Prostate Cancer Index Composite (EPIC) instrument; patients treated with 3D-CRT were assessed using the Prostate Cancer Symptoms Index (PCSI); PCSI scores were inverted to match those of the EPIC scale.

Treatment dose ranges were 75.6-79.2 Gy for IMRT, 74-82 Gy relative biological effectiveness values for PBT, and 66.4-79.2 Gy for 3D-CRT.

Mean patient-reported bowel QoL scores in the immediate post-treatment period were 93.3 on a scale of 0-100 for PBT, 78.5 for IMRT, and 88.2 for 3D-CRT (P vs. PBT less than .001 for both comparisons). The differences from baseline in IMRT and 3D-CRT, but not in PBT, were considered clinically significant.

At 24 months, mean respective bowel QoL scores were 91.8, 87.6, and 90.2, respectively, with clinically significant differences between PBT and the other two modalities.

 

 

Dr. Gray acknowledged that the retrospective nature of the study and the use of different scoring instruments muddy the comparison waters. He noted that things may become clearer when the results of a recently launched randomized trial comparing PBT and IMRT become available. The study will look at 6-month efficacy outcomes, cost effectiveness, and toxicities at 2 years, and survival and other end points out to 10 years.

Protons Are a Costly Choice

Although the relative long-term benefits of PBT for prostate cancer may not be known for several years, one thing is sure: PBT is about 70% more expensive than IMRT, said Dr. James Yu, a radiation oncologist at Yale University in New Haven, Conn.

Neil Osterweil/IMNG Medical Media
Dr. James Yu

Dr. Yu and colleagues looked at data on patients who received IMRT or PBT as primary therapy for prostate cancer in the Medicare Chronic Condition Data Warehouse, a national database that captures 100% of Medicare fee-for-service claims for patients with specific chronic conditions.

They found that the median interquartile range amount that Medicare reimbursed for PBT was $32,428 vs. $18,575 for IMRT.

In early follow-up (0-6 months) genitourinary complications were significantly lower among 421 patients with who had received PBT than among 842 patients who received IMRT (5.9% vs. 9.5%; odds ratio 0.60; P = .03). Neither gastrointestinal nor other complications were significantly different, however, and at 12 months follow-up there were no significant differences between treatment types, Dr. Yu noted.

"A continued longitudinal study of the comparative effectiveness of proton radiation is needed, and we also believe that further study is needed before widespread application of proton radiation can be justified," he said.

PBT Benefit Proven in Other Cancers

A radiation oncologist who was not involved in the study commented that in the absence of evidence of a therapeutic benefit for PBT in prostate cancer over other modalities, proton therapy may better be reserved for the treatment of other cancers.

"If you have a resource that’s limited, you want to use it where you know there’s a benefit," said Dr, Jeffrey Bradley, professor of radiation oncology at Washington University in St. Louis.

His center is building a single-vault proton-beam facility that is expected to open in the summer of 2013. Dr. Bradley said that although they will likely treat patients with prostate cancer, he envisions the main role of the center to be treatment of pediatric and adult tumors of the central nervous system, sarcomas, ocular neoplasms, and other conditions where the benefits of PBT are better documented.

Dr Gray, Dr. Yu, and Dr. Bradley each reported no conflicts of interest.

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Only Short-Term Advantage for Protons in Prostate Cancer
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AT THE ANNUAL MEETING OF THE AMERICAN SOCIETY FOR RADIATION ONCOLOGY

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Major Finding: Mean patient-reported bowel quality-of-life scores in the immediate posttreatment period were 93.7 on a scale of 0-100 for PBT, 78.5 for IMRT, and 88.2 for 3D-CRT (P vs. PBT less than .001 for both comparisons). There were no significant between-treatment differences at 2 years, however.

Data Source: Investigators conducted a retrospective cohort study.

Disclosures: Dr Gray, Dr. Yu, and Dr. Bradley each reported no conflicts of interest.