Stereotactic body radiation therapy in patients with metachronous oligorecurrent prostate cancer: A single-center experience

Introduction and objective: Metachronous oligorecurrence in prostate cancer (PCa) occurs in patients with localized disease who, after failed radical treatment, develop oligometastases. Metastasis-directed stereotactic radiotherapy (SBRT) aims to delay androgen deprivation therapy. In this study, we report our experience to elucidate the role of SBRT in a selected population of patients with metachronous oligorecurrence.

Material and methods: Retrospective analysis of patients treated with SBRT for oligorecurrent PCa between November 2015 and December 2020. We detailed clinicopathological characteristics at disease onset (age, PSA, stage, primary treatment), clinical scenario at diagnosis of oligorecurrence (PSA, PSA velocity, metastases characteristics), progression-free survival, castration resistance-free survival, dose, and toxicity of SBRT.

Results: Thirty-eight SBRT treatments were applied to 13 lymph node and 25 bone metastases in a total of 28 patients. After a follow-up of 34.57 months (21.17-57.59), 17 patients had radiological progression of the disease and 11 presented castration resistant PCa. PFS and CRFS were 21.93 and 44.13 months, respectively. Only 2 patients presented grade 1 toxicity.

Conclusions: In patients with metachronous oligorecurrent PCa, SBRT constitutes a safe and effective treatment that allows delaying the onset of androgen deprivation therapy and the time to castration resistance, assuming low levels of toxicity.