Vol.:(0123456789) 1 3 Medical Oncology (2018) 35:75 https://doi.org/10.1007/s12032-018-1137-0 ORIGINAL PAPER Stereotactic body radiotherapy for castration‑sensitive prostate cancer bone oligometastases Giuseppe Fanetti 1,2  · Giulia Marvaso 1  · Delia Ciardo 1  · Annaisabel Rese 3,4  · Rosalinda Ricotti 1  · Elena Rondi 5  · Stefania Comi 5  · Federica Cattani 5  · Dario Zerini 1  · Cristiana Fodor 1  · Ottavio de Cobelli 2,6  · Roberto Orecchia 7  · Barbara A. Jereczek‑Fossa 1,2 Received: 19 March 2018 / Accepted: 13 April 2018 © Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract 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 fve lesions at time of SBRT and hormone-naïve disease at the frst extra-regional localization, treated between 03/2012 and 11/2016. Prostate-specifc 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-fve 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-fve 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-specifc 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 signifcant diferences were found for those outcomes. SBRT is safe and allows high 1-year LC rate (83%) with low toxicity profle. No signifcant improvement in outcomes was registered with the addition of ADT to SBRT. Keywords Prostate cancer · Castration-sensitive prostate cancer · Oligometastases · Bone metastases · Stereotactic body radiotherapy · Androgen deprivation therapy Introduction Prostate cancer (PCa) is the second most common cancer among men globally, with an estimated 1.1 million new cases and over 300,000 deaths annually [1]. In the last dec- ade, the debate principally involves the management of the oligometastatic disease, defned as an intermediate state of tumor spread with limited metastatic capacity [2, 3]. This concept has changed the clinical practice allowing for a local treatment, such as surgery or radiation therapy, rather than a systemic approach, given the limited number and site of metastatic lesions. PCa is a radiosensitive disease, and stereotactic body radiation therapy (SBRT) is emerging as a promising treat- ment option with low toxicity for the management of the oligometastatic patient both at diagnosis and at recurrence (local consolidative therapy and metastasis-directed ther- apy) [4]. SBRT, similar to surgery, is a spatially targeted Giuseppe Fanetti and Giulia Marvaso equally contributed to the article and should be considered co-frst author. * Giuseppe Fanetti giuseppe.fanetti@cro.it 1 Division of Radiotherapy, European Institute of Oncology, Ripamonti 435, 20141 Milan, Italy 2 Department of Oncology and Hemato-oncology, University of Milan, Milan, Italy 3 Division of Radiotherapy, A.O.U. Federico II, Naples, Italy 4 University of Naples, Naples, Italy 5 Unit of Medical Physics, European Institute of Oncology, Milan, Italy 6 Division of Urology, European Institute of Oncology, Milan, Italy 7 Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, Milan, Italy