Management of Postprostatectomy Biochemical Relapse With Salvage Radiotherapy: Results of an International Survey.

Objectives: The management of patients with postprostatectomy salvage radiotherapy (SRT) presents radiation oncologists (ROs) with multiple treatment decisions that may impact outcomes. As the evidence addressing these issues is limited to retrospective data, it was hypothesized that widely disparate treatment paradigms exist.

Methods: A 21-question survey was sent through SurveyMonkey to members of the American Society of Radiation Oncology.

Results: A total of 999 ROs responded. Threshold rPSA values to initiate SRT ranged from 0.1 to 1 ng/mL. The highest dose prescribed by ROs ranged from <60 to >70.2 Gy. Elective lymph node irradiation was offered by 74%, and the majority (64%) referenced the Roach formula, Kattan nomogram, or D'Amico risk stratification to decide when it was appropriate. There was variability in pelvic field design with a preference to place the superior field border at either the upper, middle, or lower sacroiliac joint by 57.6%, 28.8%, and 13.6% of respondents, respectively. Adjuvant androgen deprivation therapy (ADT) was offered by 74%.

Conclusions: Disparate treatment paradigms exist for SRT that may impact patient outcomes. Variability includes patient selection, treatment design, and recommendations for ADT. Many reference formulas to predict the benefit of pelvic lymph node irradiation that are not yet validated in the postprostatectomy setting. These data make it clear that well-designed, prospective clinical trials are needed to better evaluate the role of larger treatment fields, dose escalation, and ADT for the thousands of patients who are treated with postprostatectomy SRT each year.