A pooled patient‐reported outcomes analysis of moderately hypofractionated proton beam therapy and photon‐based intensity modulated radiation therapy for low‐ or intermediate‐risk prostate cancer

• Published in: The Prostate Vol. 84; no. 4; pp. 395 - 402
• Main Authors: Lukez, Alexander, Handorf, Elizabeth, Mendenhall, Nancy P., Henderson, Randal H., Stish, Bradley J., Davis, Brian J., Hallman, Mark, Horwitz, Eric M., Vapiwala, Neha, Wong, Jessica Karen
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.03.2024
• Subjects: Humans; hypofractionation; Male; Patient Reported Outcome Measures; patient reported outcomes; Prostate - radiation effects; Prostate cancer; Prostatic Neoplasms - radiotherapy; proton therapy; Proton Therapy - adverse effects; quality of life; Radiation therapy; Radiotherapy, Intensity-Modulated - adverse effects; Toxicity; prostate cancer; proton therapy; hypofractionation; quality of life; patient reported outcomes
• ISSN: 0270-4137; 1097-0045
• DOI: 10.1002/pros.24660

Background We sought to characterize and compare late patient‐reported outcomes (PROs) after moderately hypofractionated intensity modulated radiation therapy (IMRT) and proton beam therapy (PBT) for localized prostate cancer (PC). Methods This multi‐institutional analysis included low‐ or intermediate‐risk group PC patients treated with moderately hypofractionated radiation to an intact prostate stratified by treatment modality: IMRT or PBT. The primary outcomes were prospectively collected patient‐reported late gastrointestinal (GI) and genitourinary (GU) toxicity assessed by International Prostate Symptom Score (IPSS) and Expanded PC Index Composite (EPIC). Multivariable regression analysis (MVA) controlling for age, race, and risk group tested the effect of time, treatment, and their interaction. Results 287 IMRT and 485 PBT patients were included. Intermediate risk group (81.2 vs. 68.2%; p < 0.001) and median age at diagnosis (70 vs. 67 years; p < 0.001) were higher in the IMRT group. On MVA, there was no significant difference between modalities. PBT IPSS did not differ from IMRT IPSS at 12 months (odds ratio [OR], 1.19; p = 0.08) or 24 months (OR, 0.99; p = 0.94). PBT EPIC overall GI function at 12 months (OR, 3.68; p = 0.085) and 24 months (OR 2.78; p = 0.26) did not differ from IMRT EPIC overall GI function. At 24 months, urinary frequency was no different between PBT and IMRT groups (OR 0.35; p = 0.096). Conclusions This multi‐institutional analysis of low‐ or intermediate‐risk PC treated with moderately hypofractionated PBT and IMRT demonstrated low rates of late patient‐reported GI and GU toxicities. After covariate adjustment, late GI and GU PROs were not significantly different between PBT or IMRT cohorts.