A review examined the dosimetric rationale and theoretical benefit of proton radiation for prostate cancer and the current state of the clinical evidence for efficacy and toxicity, derived from both large claim-based datasets and prospective patient-reported data.

This review pointed out that the published data are mixed, and clinical equipoise persists, for that only the results of a large prospective randomized clinical trial currently accruing and also a large prospective pragmatic comparative study, will provide more rigorous evidence regarding the clinical and comparative effectiveness of proton therapy for prostate cancer.