Comparative effectiveness study of patient‐reported outcomes after proton therapy or intensity‐modulated radiotherapy for prostate cancer

Abstract

Background Data continues to emerge on the relative merits of different treatment modalities for prostate cancer. The purpose of this study is to compare patient-reported quality-of-life outcomes (QOL) after proton therapy (PT) and intensity-modulated radiation therapy (IMRT) for prostate cancer. Methods A comparison was performed of prospectively collected QOL data using the expanded prostate cancer index (EPIC) questionnaire. QOL data was collected during the first 2 years following treatment for men treated with PT and IMRT. PT was delivered to 1,243 men at a single center to 76-82Gy. IMRT was delivered to 204 men included in the Prostate Cancer Quality Assurance Study (PROSTQA) in doses of 75.6-79.4Gy.The Wilcoxon rank sum test was used to compare EPIC outcomes by modality using baseline-adjusted scores at different time points. Individual questions were assessed by converting to binary outcomes and testing with generalized estimating equations. Results No differences in changes in summary scores for bowel, urinary incontinence, urinary irritative/obstructive, and sexual domains were seen between the two cohorts. However, more men treated with IMRT reported moderate/big problems with rectal urgency (p=0.02) and frequent bowel movements (p=0.05) than men treated with PT. Conclusions There were no differences in QOL summary scores between the IMRT and PT cohorts during early follow-up up to 2-years. Response to individual questions suggests possible differences in specific bowel symptoms between the two cohorts. These outcomes highlight the need for further comparative studies of PT and IMRT.

The evolution of proton beam therapy: Current and future status (Review)

“…Thus, long-term follow up is required to justify the increasing use of PBT for prostate cancer. It has been demonstrated that PBT is a safe and effective method for patients with localized prostate cancer (56)(57)(58)(59). However, it is necessary to further compare PBT with other treatment regimens for local prostate cancer to determine the optimal treatment regimen for different patients (60).…”

Proctitis Following Stereotactic Body Radiation Therapy for Prostate Cancer

“…The mean bowel summary score change from baseline to 24 months in this study was -1.6. This change compares favorably to that seen at 24 months with conventionally fractionated IMRT and proton therapy -7.4 and -3.7, respectively [3][4][5]14]. The present study has several identifiable limitations.…”

“…The bowel QOL score is at its lowest 1 or 2 months after treatment, but improves slowly thereafter to near baseline by 1-2 years after treatment [3][4][5]. In our series, most moderate to big problems were seen at 1 month post-SBRT with approximately 10% of patients reporting moderate to big problems with bowel urgency and/or frequency ( Figure 4).…”

“…This compares favorably with 15-19% incidence of moderate to severe bowel urgency and frequency seen two months after conventionally fractionated external beam radiation therapy or brachytherapy [3]. Unlike conventional modalities, this increase in bowel bother was transient and returned to near baseline by 3 months post-SBRT [3,5]. A second transient increase in bowel bother occurred at 12 months with approximately 7% of patients reporting moderate to big problems.…”

“…Post-treatment bowel function is a primary determinant of quality of life following radiation therapy for prostate cancer [1][2][3][4][5]. Late proctitis occurs at a frequency of 5-20% with conventionally fractionated treatment [6].…”