Stereotactic body radiotherapy for lung oligometastatic prostate cancer: An international retrospective multicenter study.

Management of prostate cancer (PCa) patients with lung oligometastases remains unclear in the absence of published data. The aim of this study was to evaluate the efficacy of Stereotactic Body Radiotherapy (SBRT) in this setting. We conducted a multicenter retrospective study that included 35 PCa patients treated with SBRT for lung oligometastases in 7 centers across 3 countries. The efficacy was evaluated by the progression free-survival (PFS), defined as pre-SBRT PSA + 25 % or nadir PSA + 25 % and + 2 ng/mL or radiological progression if it occurred before biochemical progression. The local recurrence free-survival (LRFS), distant metastases free-survival (DMFS), Overall Survival (OS) and Androgen Deprivation Therapy free-survival were also assessed. Survival was estimated using the Kaplan Meier method. 35 patients were included with lung oligometastases staged with PET-CT for 97 % and histologically biopsy confirmed for 51 %. 77 % had an oligorecurrent metastatic disease. The median pre SBRT PSA was at 1.7 ng/mL [0.8, 3.0] and the median follow-up after SBRT was 28.7 months. The median PFS was 21.6 months [95 %CI: 21.6; NA] and the median DMFS was 32.4 months [95 %CI: 22.2-NA]. No parameters were significantly associated with PFS on the univariate and multivariate models.For patients who did not start ADT before or concomitantly with SBRT (n = 18), the 1-year ADT free-survival rate was estimated at 87.2 % [71.9;100]. SBRT for PCa lung oligometastases offers good oncological outcomes, comparable to those reported for bone and/or lymph node metastases SBRT. Our results encourage the inclusion of patients with lung oligometastatic disease in clinical trials designed to assess the value of SBRT. SBRT for prostate cancer lung oligometastases shows promising results, similar to treatments for bone or lymph node oligometastases.