ESTRO 2024 - Abstract Book

S1939

Clinical - Mixed sites, palliation

ESTRO 2024

University Hospital of Basajoz, Radiation Oncology, Badajoz, Spain

Purpose/Objective:

Nowadays stereotactic radiotherapy (SABR) has been a recognized approach for treating oligometastatic patients, defined as those with up to 5 metastatic lesions. This concept is based on the hypothesis that patients with a limited disease burden can experience long-term disease control or delaying a switch in systemic therapies by incorporating local ablative therapy into the standard systemic care.

Based in retrospective studies, actual guidelines recommend the management of extracranial disease with local therapy

However, long term randomized data is not yet available, there are phase II studies like SABR-COMET, that provides essential support for this clinical practice.

The role of add local therapy on oligoprogresive or oligorecurrent patients is complex and some considerations must take into account in a multidisciplinary team.

The aim of this study is to review oligometastatic patients who have received radical ablative treatment at our institution and analyze their Overall Survival (OS), Progression-Free Survival (PFS), Local Control (LC) and parameters that could affected it.

Material/Methods:

This retrospective study encompass 62 patients treated with SABR in a period between January 2020 and December 2022. The study involved patients who had metastases at the time of the initial diagnosis, often referred to as synchronous cases, as well as patients who developed metastases after the initial diagnosis, known as oligorecurrence and/or oligoprogression cases. Reirradiation cases were not included in the analyses.

Appropriate staging for all patients with FDG PET and MRI for bone metastasis were performed in the 3 months previous at the start of treatment.

All the treatments were delivered with RTE VMAT/IMRT in LINAC. Simulation was realized with specifical inmobilization for each location and the treatment was administrated in 1-10 fractions. To verify the patient position a cone beam was carry on in every fraction. The treatment was administrated every other day except for >6 fractions schemes.

Descriptives analyses were realized for the variables included in the study.

To analyze our results in terms of Overall Survival (OS) and Progression-Free Survival (PFS), we employed Kaplan Meier curves. Additionally, to assess differences in survival based on categorical variables, a Cox-regression test was employed.

Results: