ESTRO 2021 Abstract Book

S1144

ESTRO 2021

8.4). However, 6 months recovery was reported, with difference lower than MCID at last evaluation (2.08 increase and 2.8 decrease in the control and treatment arm, respectively). At 3 months, appetite was significantly increased in overall population, control and treatment arms (11 points improvement in all groups), but this difference if compared to baseline was recovered at 6 months evaluation. Conclusion In oligometastatic CRPC undergoing abiraterone treatment, GHS significantly decreased after 3 months, but recovered at last follow up. No impact of SBRT was reported on GHS, physical, role, emotional or cognitive functioning. SBRT significantly influenced social functioning at three months, but this difference was not reported at 6 months. PO-1394 Stereotactic body radiotherapy for prostate cancer lymph node metastases: a systematic review A. Zamagni 1,2 , M. Bonetti 2 , M. Buwenge 1,2 , M. Ntreta 1 , G. Tolento 1 , S. Cammelli 1,2 , C.M. Donati 1,2 , E. Lodi Rizzini 1 , M. Boccardi 3 , A. Re 3 , F. Deodato 3,4 , S. Cilla 5 , G. Macchia 3 , A.G. Morganti 1,2 1 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 2 Department of Experimental, Diagnostic and Specialty Medicine - DIMES, Alma Mater Studiorum Bologna University, Bologna, Italy; 3 Radiation Oncology Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy; 4 Istituto di Radiologia, Università Cattolica del Sacro Cuore, Roma, Italy; 5 Medical Physics Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy Purpose or Objective The standard treatment for oligometastatic prostate cancer (PC) is still considered androgen deprivation therapy. However, increasing evidence suggests that a more targeted management could play a “curative” role within a multimodal treatment approach since it allows satisfactory local control and eventually delay of systemic treatments. Lymph nodes (LN) isolated oligorecurrences identify a favorable subset of patients (pts) in terms of disease progression. Therefore, we performed a systematic review on stereotactic body radiotherapy (SBRT) as metastases directed therapy in this setting. Primary objectives of the study were local control (LC) and progression-free survival (PFS). Materials and Methods A systematic literature search for relevant studies was conducted in PubMed, Scopus, and Cochrane library up to July 1 st , 2020. Papers reporting LC and/or PFS in pts with LN metastases from oligorecurrent PC treated with SBRT alone or in combination with systemic treatments were selected. Data on androgen deprivation therapy-free survival (ADT-FS), overall survival (OS) and toxicity were also collected from the selected studies. Results Fifteen studies were eligible (414 patients with LN metastases). All but three studies were retrospective analyses. LC and PFS results were reported in 15 and 12 papers, respectively. The median number of pts per study was 25 (range 7-94), with only one study reporting results on more than 50 pts and six studies reporting results on less than 20 pts. High heterogeneity was observed in terms of pts selection (i.e., number of treated lesions, systemic therapy, evaluation modalities). In one study SBRT was delivered as a single 20 Gy fraction, while in the others the median total dose ranged between 24 and 40 Gy (median: 30 Gy) in 3-6 fractions (median: 3 fractions) ( Table 1 ). LC was reported as a crude percentage in 13 studies, with a result of 100% in seven of them and ranging from 63.2% to 98.0% in the other six. Overall, only two out of 13 studies reported a crude LC lower than 90.0%. Five studies reported actuarial LC, with 2-year LC ranging from 70.0% to 100% (median: 84.0%). PFS was reported as crude rate in 11 studies, with a median of 42.9% (range: 27.3-68.8%). Two-year PFS was reported in four studies, ranging from 30.0% to 50.0% (median: 38.6%). ADT-FS was heterogeneously reported: crude ADT-FS was 68.0% and 40.0% in two studies, while one study reported 70% 1-year ADT-FS. Moreover, two studies reported a median ADT-FS of 13.6 and 7.2 months. OS was reported in three studies: 2-year OS was 92.0% and 67.0% in two of them, while the third reported 95% crude OS. SBRT tolerability was excellent, with only one patient presenting grade 3 acute toxicity and two pts presenting grade 3 late toxicity.