ESTRO 2022 - Abstract Book

S180

Abstract book

ESTRO 2022

Table 1. Baseline characteristics

Conclusion In this international prospective cohort of patients with (peri-)pancreatic tumors, we observed a low incidence of short- term major toxicity after MRgRT on a 1.5T MR-linac. The results from this analysis will be updated before the ESTRO conference in 2022.

MO-0222 Propensity score-based comparison of SBRT versus thermal ablation for hepatocellular carcinoma

C. Franzese 1 , D. Poretti 2 , T. Comito 3 , R. Muglia 2 , L. Lo Faro 1 , C. Ceriani 2 , V. Pedicini 2 , A. Teriaca 3 , E. Lanza 2 , F. D'antuono 2 , L. Solbiati 4 , P. Mancosu 3 , S. Tomatis 3 , M. Scorsetti 1 1 Humanitas University, Humanitas Research Hospital IRCCS, Radiotherapy and Radiosurgery, Milano, Italy; 2 Humanitas Research Hospital IRCCS, Unit of Interventional Radiology, Milano, Italy; 3 Humanitas Research Hospital IRCCS, Radiotherapy and Radiosurgery, Milano, Italy; 4 Humanitas University, Humanitas Research Hospital IRCCS, Unit of Interventional Radiology, Milano, Italy Purpose or Objective Hepatocellular carcinoma (HCC) is the third cause of death worldwide. Our aim was to analyse a large monocentric group of HCC patients treated with thermal ablation (TA) or stereotactic body radiation therapy (SBRT). Materials and Methods We included HCC treated with TA or SBRT between 2010 to 2020. Inclusion criteria for TA were: diagnosis of HCC with pathological confirmation or typical imaging features; tumors deemed inoperable; Child-Pugh < B9; tumor number ≤ 4; maximum diameter ≤ 5 cm. SBRT was considered when TA was not feasible, when tumor has not responded to transarterial embolization, in case of coagulative disorders. Primary endpoint was the comparison of local control (LC) and overall survival (OS) between the two groups. Results We included 576 lesions and 334 patients, 201 (60.2%) underwent TA and 133 (39.8%) underwent SBRT. Patients were more likely treated with SBRT if BCLC stage C, Child-Pugh B, HBV positive, with metabolic syndrome. Median follow-up was 19 months. 1- and 2-years LC was 78.6% and 65.7% for TA and 87.9% and 79.5% for SBRT. After application of propensity score, the superiority of SBRT was not confirmed (p = 0.235). OS at 1 and 2 years was 95.4% and 81.6% for TA and 78.6% and 48.0% for SBRT. After adjusting for propensity score, OS was comparable between the two groups (p= 0.060). Conclusion we confirm the efficacy and safety of TA and SBRT for the management of HCC. With the use of propensity score we demonstrated comparable results between the two treatment options.

MO-0223 Simulation-CT Skeletal Muscle Index as a Biomarker for CRT compliance and survival in rectal cancer