1 3 World J Urol DOI 10.1007/s00345-016-1860-0 ORIGINAL ARTICLE Stereotactic body radiotherapy in oligometastatic prostate cancer patients with isolated lymph nodes involvement: a two-institution experience Gianluca Ingrosso 1 · Fabio Trippa 2 · Ernesto Maranzano 2 · Alessandra Carosi 1 · Elisabetta Ponti 1 · Fabio Arcidiacono 2 · Lorena Draghini 2 · Luana Di Murro 1 · Andrea Lancia 1 · Riccardo Santoni 1 Received: 22 October 2015 / Accepted: 18 May 2016 © Springer-Verlag Berlin Heidelberg 2016 Keywords Prostate cancer · Oligometastasis · Stereotactic body radiotherapy · Local control · Androgen deprivation therapy-free survival Introduction Oligometastatic disease is considered an intermediate state between localized and widespread cancer, with a unique biological profile [1]. There is an increasing evidence that patients with a limited number of metastases have a bet- ter prognosis compared to those with extensive metastatic disease [2, 3]. Therefore, in oligometastatic cancer patients, a local treatment such as stereotactic body radiotherapy (SBRT) might be effective in delaying disease progression [4, 5]. Being prostate cancer a slowly growing tumor with a high life expectancy, patients with oligometastases from prostate cancer can represent an ideal target for SBRT. Moreover, SBRT may defer androgen deprivation therapy (ADT), which is the current standard of care but can have a detrimental effect on patient quality of life [6]. This retrospective study aimed to analyze overall sur- vival (OS), local control (LC), biochemical progression- free survival (b-PFS), and toxicity in 40 patients affected by isolated prostate cancer lymph node metastases. Andro- gen deprivation therapy-free survival (ADT-FS) was also evaluated in the subset of patients who underwent SBRT without ADT. Materials and methods From September 2008 to December 2014, 40 patients with 47 isolated lymph nodes of recurrent prostate cancer were treated with SBRT in two Italian Centers (“Tor Vergata” Abstract Objective Stereotactic body radiotherapy (SBRT) is emerging as a treatment option in oligometastatic cancer patients. This retrospective study aimed to analyze local control, biochemical progression-free survival (b-PFS), and toxicity in patients affected by isolated prostate can- cer lymph node metastases. Finally, we evaluated androgen deprivation therapy-free survival (ADT-FS). Methods Forty patients with 47 isolated lymph nodes of recur- rent prostate cancer were treated with SBRT. Mostly, two differ- ent fractionation schemes were used: 5 × 7 Gy in 23 (48.9 %) lesions and 5 × 8 Gy in 13 (27.7 %) lesions. Response to treat- ment was assessed with periodical PSA evaluation. Toxicity was registered according to RTOG/EORTC criteria. Results With a mean follow-up of 30.18 months, local con- trol was achieved in 98 % of the cases, with a median b-PFS of 24 months. We obtained a 2-year b-PFS of 44 % with 40 % of the patients ADT-free at last follow-up (mean value 26.18 months; range 3.96–59.46), whereas 12.5 % had a mean ADT-FS of 13.58 months (range 2.06–37.13). Late toxicity was observed in one (2.5 %) patient who manifested a grade 3 gastrointestinal toxicity 11.76 months after the end of SBRT. Conclusion Our study demonstrates that SBRT is safe, effective, and minimally invasive in the eradication of lim- ited nodal metastases, yielding an important delay in pre- scribing ADT. * Gianluca Ingrosso ingrosso.gianluca@gmail.com 1 Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, Tor Vergata General Hospital, viale Oxford 81, 00133 Rome, Italy 2 Department of Oncology, Radiation Oncology Center, “S. Maria” Hospital, Terni, Italy