ESTRO 2025 - Abstract Book

S2397

Interdisciplinary – Other

ESTRO 2025

The interdisciplinary and multi-institutional reRT peer-review meeting had three main discussion points: indication, prescription dose and tolerated EQD2 cumulative dose constraints to relevant OARs and/or dose accumulation. It consisted in a one-hour meeting, twice a week, led by an experts’ group of RO and physicists from Lyon and Nantes. For reRT case submission, outside institutions were asked to provide, a few days before, a summary indicating the medical intent, the total dose and fractionation of the previous and the current radiotherapy (RT) and their corresponding DICOM information. These latter were shared via a secured platform and imported in the MIM software. Then a medical physicist performed the image registration and dose accumulation in EQD2. During the peer-review meeting, a systematic patient’s anamnesis was reported by the referent RO and the requested medical opinion was debated using MIM (Fig.1). The provided outcomes from these peer-review meetings were classified and reported for all the reRT patient cases discussed from December 2023 to November 2024.

Results

Among 47 meetings, 113 reRT patient cases were discussed. A total of 13 outside institutions, including 8 regional centers, participated to them and presented 41% of the total cases (Fig.2). The median number of reRT patient cases reviewed per meeting was 2 (min:1; max:6). Peer-review meetings disapproved the RT indication, modified or proposed an initial dose prescription, suggested modification of contours or margins, disapproved the EQD2 cumulative dose to relevant oars and thus asked for a new treatment plan, for 16%, 35%, 10%, and 7% of patient cases respectively. Conclusion The virtual interdisciplinary and multi-institutional peer-review meetings implemented in our institution seemed to be an important step in the reRT workflow as it significantly helped in the validation and in the clinical decision making of reRT patient cases.

Keywords: reirradiation, peer-review, decision-making