Stereotactic body radiotherapy for castration-sensitive prostate cancer bone oligometastases

To evaluate outcome in patients treated with stereotactic body radiotherapy (SBRT) on bone oligometastases from castration-sensitive prostate cancer after primary treatment. We retrospectively collected data of patients with less than five lesions at time of SBRT and hormone-naïve disease at the first extra-regional localization, treated between 03/2012 and 11/2016. Prostate-specific antigen (PSA) was measured every 3 months after SBRT. Imaging was performed in case of progression. Survival analysis was performed with Kaplan-Meier (log-rank test) approach. Fifty-five patients were treated on 77 bone oligometastases. Median age, initial PSA and pre-SBRT PSA were 72 years, 9.12 and 3.5 ng/mL, respectively. Twenty-five patients (45%) received SBRT alone while the remaining 30 patients (55%) received concomitant ADT. Median follow-up was 24.6 months (range 3.0-67.2 months). No acute or late toxicity of grade > 1 was reported. Clinical progression was observed in 38 (69%) patients. 1-year biochemical progression-free survival (b-PFS), clinical progression-free survival (c-PFS), prostate-specific survival (PCSS) and local control (LC) rates were 51, 56, 100 and 83%, respectively. Comparing patients treated with SBRT alone and with concomitant ADT, no significant differences were found for those outcomes. SBRT is safe and allows high 1-year LC rate (83%) with low toxicity profile. No significant improvement in outcomes was registered with the addition of ADT to SBRT.

Medical oncology (Northwood, London, England). 2018 Apr 18*** epublish ***

Giuseppe Fanetti, Giulia Marvaso, Delia Ciardo, Annaisabel Rese, Rosalinda Ricotti, Elena Rondi, Stefania Comi, Federica Cattani, Dario Zerini, Cristiana Fodor, Ottavio de Cobelli, Roberto Orecchia, Barbara A Jereczek-Fossa

Division of Radiotherapy, European Institute of Oncology, Ripamonti 435, 20141, Milan, Italy. ., Division of Radiotherapy, European Institute of Oncology, Ripamonti 435, 20141, Milan, Italy., Division of Radiotherapy, A.O.U. Federico II, Naples, Italy., Unit of Medical Physics, European Institute of Oncology, Milan, Italy., Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy., Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, Milan, Italy.