Proton‐beam therapy after radical prostatectomy: Continued DVH idolatry?

Abstract

Proton‐beam therapy results in lower doses to the bladder and rectum compared with intensity‐modulated radiation therapy. Despite these dosimetric differences, genitourinary and gastrointestinal toxicity is similar.

Proton beam therapy after radical prostatectomy

“…Last, with regard to Dr. Lee's assertions that “not all questions should be asked or answered” and “the magnitude of the difference in toxicity…is likely to be very small if one exists at all,” we agree that resources should be devoted to investigating possible survival benefits of PBT in patients with certain cancers. However, the management of toxicities and that of radiation‐associated second malignancies remain incredibly meaningful endpoints to patients, providers, and payers alike, particularly among postprostatectomy patients, who often are younger and expected to survive decades after their diagnosis.…”

“…As Dr. Lee mentions, the most recent American Urological Association (AUA)/American Society for Radiation Oncology (ASTRO) guidelines regarding postprostatectomy radiotherapy cite a “lack of high‐quality studies” on “novel” treatment modalities and preclude mention of PBT . We agree that our analysis was limited by its retrospective, potentially underpowered nature .…”

“…In the accompanying editorial for our article, Dr. Lee raised several valid points regarding our findings and, more broadly, the use of proton‐beam therapy (PBT) in radiotherapy for prostate cancer (PC) . First, we would like to thank Dr. Lee for taking the time to provide his thoughtful commentary.…”

Comparative Analysis of 5-Year Clinical Outcomes and Patterns of Failure of Proton Beam Therapy Versus Intensity Modulated Radiation therapy for Prostate Cancer in the Postoperative Setting

“…5 However, comparisons of disease control outcomes and patterns of failure between both modalities remain understudied, which is an essential component of evaluating the utility of PBT in this setting. 6,7 Although the primary theoretical advantage of PBT relates to toxicity reduction, it is imperative to demonstrate that outcomes of PBT are similar to those of IMRT. This is particularly important because PBT is associated with numerous uncertainties in adequately delivering dose to the target, such as relating to on-board imaging, patient setup, beam delivery, and dose calculations (eg, range uncertainties); these could in turn influence clinical outcomes.…”