ESTRO 2021 Abstract Book

S301

ESTRO 2021

scores: SINS ≥ 6 (1); time from primary diagnosis (TPD) > 21 months (-1); ECOG = 1 and > 1 (1 and 2, respectively); and 1 and > 1 organ systems involved (1 and 2) (Table 1). Cox hazards analysis demonstrated concordance values of 0.721 and 0.749 in the training and internal validation sets, respectively (Figures 1a and 1b). Patients with scores ≤ 0, 1-3, and ≥ 4 were then separated into favorable (n=172), intermediate (n=220), and poor-survival groups (n=32). These groups demonstrated 2-year OS of 81%, 45%, and 14% (p<0.0001), with similar results in the validation set (Figures 1c and 1d). After exclusion of the poor-survival group, the LC analysis revealed that Bilsky > 0 (HR=2.25, p<0.0001), soft tissue involvement (HR=2.47, p<0.0001), and prior treatment (HR=2.78, p<0.0001) were predictive of decreased time to local failure. Histology was not predictive of LC or OS. Interestingly, the survival score was also predictive of local failure, with each 1 point increase from -1 to 3 resulting in a 35% increased risk of local failure (HR=1.35, 1.17-1.56).

Conclusion We developed and internally validated a score predictive of OS and time to local failure among patients receiving spine SBRT, reinforcing the prognostic value of performance status, systemic disease burden, and TPD. We also identified the SINS score (≥ 6) as a novel predictor of decreased OS. We propose this novel score as a decision-making tool to help optimize patient selection for spine SBRT. OC-0406 Short-course palliative radiotherapy of advanced solid cancer (sharon project): a pooled analysis. E. Farina 1 , F.A. Mauro 2 , G. Macchia 3 , F. Deodato 3,4 , D. Pezzulla 3 , S. Cilla 5 , F. Cellini 4,6 , G. Siepe 7,8 , A. Zamagni 7,8 , M.A. Sumon 9 , K.A.F.M. Uddin 10 , T. Wondemagegnhu 11 , A.A. Woldemariam 11 , B.T. Deressa 11 , L. Caravatta 12 , M. Buwenge 7,8 , S. Cammelli 7,8 , A.G. Morganti 7,8 1 Radiation Oncology Unit, Maria Cecilia Hospital, GVM Care & Research, Cotignola (RA), Cotignola (RA), Italy; 2 Radiation Oncology Unit, Maria Cecilia Hospital, GVM Care & Research, Cotignola (RA), 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; 6 Fondazione Policlinico Universitario A. Gemelli, IRCCS, UOC di Radioterapia, Dipartimento di Scienze Radiologiche, Radioterapiche ed Ematologiche, Roma, Italy; 7 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 8 Department of Experimental, Diagnostic, and Specialty Medicine - DIMES, Alma Mater Studiorum Bologna University, Bologna, Italy; 9 Clinical Oncology, Kurmitola General Hospital, Dhaka, Bangladesh; 10 Department of Radiation Oncology, United Hospital Limited, Dhaka, Bangladesh; 11 Radiotherapy Department, Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia; 12 Department of Radiation Oncology, SS. Annunziata Hospital, G. D'Annunzio University of Chieti, Chieti, Italy Purpose or Objective To evaluate safety and efficacy in patients with symptomatic advanced and metastatic solid cancer treated with palliative hypo-fractionated accelerated radiotherapy (RT).