ESTRO 2021 Abstract Book

S1143

ESTRO 2021

four categories based on 5-year bRFS values: group 1: low-risk (bRFS > 80%), group 2: intermediate risk (bRFS: 60-80%), group 3: high risk (bRFS: 40-59.9%), and group 4: very high risk (bRFS: < 40%). [ Figure 1 ] Conclusion This systematic analysis of a large patients’ series allowed the identification of unpredictable correlations potentially useful to generate new hypotheses.

PO-1393 ARTO (NCT03449719), quality of life monocentric report after stereotactic treatment and abiraterone G. Francolini 1 , V. Di Cataldo 2 , B. Detti 1 , S. Lucidi 3 , E. Scoccimarro 3 , M. Mariotti 3 , A. Peruzzi 3 , B. Guerrieri 3 , P. Garlatti 3 , M. Loi 1 , M. Mangoni 3 , I. Desideri 3 , I. Meattini 3 , L. Livi 3 1 Azienda Ospedaliera Universitaria Careggi, Radiotherapy Unit, Florence, Italy; 2 Istituto Fiorentino di Cura e Assistenza (IFCA), Radiotherapy Unit, Florence, Italy; 3 University of Florence, Department of Experimental and Clinical Biomedical Sciences "M. Serio", Florence, Italy Purpose or Objective In January 2019 a multicenter, randomized trial (ARTO-NCT03449719) was started in nine italian centers. Fifty five per cent of the accrual target population has been currently enrolled. Aiming to explore the impact of radiotherapy on patients reported Quality of Life (QoL), here we present a report of a preliminary cohort of patients with at least 6 months of follow-up enrolled at the promoting institute of the trial. Materials and Methods Only patients enrolled at the trial promoting institute were included. All patients were affected by oligometastatic Castrate Resistant Prostate Cancer (CRPC), defined as < 3 non-visceral metastatic lesions. Patients were randomized 1:1 to receive either Abiraterone Acetate alone (control arm) or associated with stereotactic body radiation therapy (SBRT) on all sites of disease (treatment arm). QoL evaluation by EORTC QLQ-C30 was performed every three months after randomization. Data about QoL were available for 29 patients (16 and 13 in the control and treatment arm, respectively). Three and six months evaluations were the object of the current analysis. Differences between baseline, 3 and 6 months evaluation and between control and treatment arm were considered clinically significant if exceeding 10 points for global health status (GHS). Regarding other EORTC QLQ-C30 questionnaire items, differences exceeding Minimal clinically important difference (MCID) reported in literature were considered significant. Results After three months, an average decrease of 13 points in terms of GHS was reported for the overall population. Difference between average values of decrease reported in control and treatment arm (11 vs 16 points, respectively) did not exceed minimal clinically important difference (MCID). However, complete recovery in terms of GHS was noticed at 6 months, with average improvement of 2, 3 and 1 point if compared to baseline in the overall population, control and treatment arms, respectively. Physical, role, emotional, cognitive and social functioning were stable if compared to baseline at three and 6 months. SBRT significantly influenced only social functioning, with a 10 points difference between control and treatment arm at three months (MCID