Low and slow.

Top Line: Is LDR brachytherapy a good salvage option for men with local recurrence after external beam radiation for prostate cancer?

The Study: RTOG 0526 was a phase 2 study that evaluated the safety and efficacy of salvage LDR brachytherapy for recurrent prostate cancer after EBRT. Toxicity has been previously reported with a 14% rate of late grade 3 toxicity and no grade 4 or 5 toxicity. Eligible patients had to have biopsy proven local recurrence at least 30 months out from definitive EBRT with a PSA < 10 and no evidence of distant or regional disease on bone scan and abdominopelvic CT. They also had to originally have had low or intermediate risk disease. Median time from EBRT to BT was 85.4 months. Over a 7 year period, 92 patients were treated with either Iodine-125 (140 Gy minimum target dose) or Palladium-103 (120 Gy minimum target dose), and most (98%) received treatment to the whole gland. At 10 years, the rate of local failure (determined by clinical exam) was 5%, biochemical failure (nadir + 2) was 46%, and distant failure was 19%. The rate of 10-year DFS was 33% and OS was 70% with roughly a quarter of deaths from prostate cancer. The long-term biochemical control rates are comparable to those reported for HIFU, SBRT, cryotherapy, and salvage prostatectomy. Modern PET imaging may improve the apparent efficacy by allowing for better patient selection for local therapy.

TBL: LDR brachytherapy is a safe and relatively effective salvage treatment for locally recurrent prostate cancer after external beam radiation. | Crook, Int J Radiat Oncol Biol Phys 2021