ESTRO 2022 - Abstract Book

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Abstract book

ESTRO 2022

(logrank p=0.9), ( Figure 1 ). The adjusted HR was 1.0 (95% CI: 0.6-1.7; p=0.9) for OS and 1.1 (95% CI: 0.8-1.6; p=0.5) for PFS. Total metastatic ablation was prognostic for OS (logrank p=0.011) and for PFS (logrank p=0.001), ( Figure 2 ). The adjusted HR for OS was 0.8 (95% CI: 0.4-0.9; p=0.032) and for PFS was HR 0.6 (95% CI: 0.4-0.8; p=0.003). Conclusion Medical operability is not independently prognostic in our cohort with oligometastatic disease. Total metastatic ablation is associated with an improved OS and PFS compared with subtotal metastatic ablation. This data suggests that treatment of all sites of metastases should be optimised.

MO-0712 Clinical outcomes of a large cohort of oligometastatic patients treated with SRT

D. Franceschini 1 , L. Cozzi 1 , L. Lo Faro 1,2 , A. Marzo 1,2 , L. Di Cristina 1,2 , B. Marini 1,2 , C. Franzese 1,2 , C. Galdieri 1 , M. Scorsetti 1,2

1 IRCCS Humanitas Research Hospital, Radiotherapy and Radiosurgery, Rozzano – Milan, Italy; 2 Humanitas University, Biomedical Sciences, Pieve Emanuele – Milan, Italy Purpose or Objective The aim of this study was to evaluate clinical outcomes in a large cohort of consecutively treated oligometastatic patients treated in our institution with stereotactic radiotherapy (SRT). Materials and Methods The study included patients affected by 1 to 5 metastases in 1 to 3 different organs treated with SRT from 2014 to 2020. Demographic features, primary tumor characteristic, patients’ features and treatments received were collected from the hospital chart. The Kaplan Meier analysis was applied to assess local control (LC), progression-free survival (PFS), distant metastases free survival (DMFS) and overall survival (OS). Results Between 2014 and 2020, 1172 patients were treated with SRT on oligometastatic sites. Patients and treatment characteristic are shown in table 1. Best local response during follow up according to RECIST criteria v 1.1 was as follow: complete response 425 patients (36.3%); partial response 533 (45.5%); stable disease 194 (16.6%); progressive disease 20 (1.7%) After a median follow up of 20.3 months, 208 patients (17.7 months) had a relapse in irradiated site(s). LC at 1, 2 and 3 years was 88%, 80.4% and 75.2%, respectively.