Favorable long-term toxicity for salvage low-dose rate prostate brachytherapy for recurrent prostate cancer after external beam radiotherapy from a phase II prospective trial (NRG Oncology/RTOG 0526)

External beam radiotherapy (EBRT) is the most commonly employed non-surgical treatment for prostate cancer in the modern era (1). Local recurrence of prostate cancer after EBRT occurs in up to 15% of patients (2-4). Local recurrence is not only common and often symptomatic, but is also a risk factor for developing distant disease. Dose-escalated EBRT reduced local recurrence risk and need for salvage local therapy in a large Phase III trial (5); however, local recurrence after EBRT remains an important problem. The morbidity and mortality associated with local failure suggests a possible role for local salvage therapies for appropriately selected patients (6,7).