ESTRO 2021 Abstract Book

S1013

ESTRO 2021

Conclusion SBRT is a very effective local therapy tool and can be safely applied in the multimodal management of patients with intermediate and advanced HCC.

PO-1225 Hypofractionated radiotherapy after induction chemotherapy for advanced pancreatic cancer P. Passoni 1 , S. Broggi 2 , N. Slim 1 , B. Longobardi 3 , M. Mori 4 , U. Peretti 5 , M. Macchini 5 , G. Orsi 5 , G. Balzano 6 , R. Castoldi 6 , M. Falconi 6 , A. Del Vecchio 3 , G.M. Cattaneo 3 , C. Fiorino 4 , S. Cascinu 7 , M. Reni 7 , N.G. Di Muzio 1 1 San Raffaele Scientific Institute, Radiation Oncology, Milan, Italy; 2 San Raffaele Scientific Insitute, Medical Physics, Milan, Italy; 3 San Raffaele Scientific Institute, Medical Physics, Milan, Italy; 4 San Raffaele Scientific Institute, Medical Physics, MIlan, Italy; 5 San Raffaele Scientific Institute, Medical Oncology, MIlan, Italy; 6 San Raffaele Scientific Institute, Pancreatic Surgery, Milan, Italy; 7 San Raffaele Scientific Institute, Medical Oncology, Milan, Italy Purpose or Objective To assess feasibility, toxicity and outcome of hypofractionated radiotherapy (RT) concomitant to capecitabine after induction chemotherapy (ChT) for advanced pancreatic cancer (APC) in stage III or IV. Materials and Methods Patients with APC without distant progression after induction Cht were considered. RT consisted of 44.25 Gy in 15 frs (EQD2=54 Gy ) to the tumor and involved lymph-nodes with margins of 10-15 mm from GTV to PTV and was delivered concomitant to capecitabine 1250mg/m2/day; 59 pts received a simultaneous integrated boost (SIB), 48-58 Gy, to a sub-volume infiltrating regional vessels (within a Phase I study) or to PET+ residual. Second and third line Cht was prescribed whenever it was possible in case of disease progression after radiochemotherapy (RCT). Acute gastrointestinal (GI) toxicity and late toxicity (defined as duodenitis, gastritis, ulcers) were evaluated in all pts. Overall survival (OS), progression free survival (PFS), distant PFS (DPFS) and local PFS (LPFS) were assessed from the start of induction ChT only in pts with stage III. The predictive value of selected parameters was tested by univariate/multivariate Cox analyses: gender, age, induction of ChT (drug combination or GMC), number of ChT cycles ( ≥ or < median number), target volume, GICA value before RT (≥ or < median value). Results From November 2004 to June 2019 244 APC, 206 stage III, 38 stage IV, were treated; median follow-up was 17.9 months. Induction Cht consisted of GMC alone in 36 pts, combination Cht with at least two drugs in 208 pts; median number of cycles was 6. Three pts did not complete RCT (1 early progression, 2 toxicity); median duration of RCT was 20 days. Acute GI toxicity. G≥2: 52/244 pts (21.3%), G3: 8 pts (3.3%). Late toxicity. G ≥2: 20 pts (8.2%), G ≥3: 15 pts