ESTRO 2025 - Abstract Book

S1185

Clinical – Lower GI

ESTRO 2025

We report here outcomes about RT (dosimetry, RT-induced adverse events), surgery (operative duration, blood loss, operative complications), early follow-up (hospital stay, postoperative complication, mortality), and surgical feasibility perception (surgeons survey). Results: Since October 2023, 12 patients were operated by 5 surgeons (1 colon tumour, 2 lung metastases, and 9 liver metastases). Median follow-up was 130 days (range: 15-318). Two patients treated for liver metastases received 3x2Gy on a second lesion. PTV objective (D95%>95%) was achieved in 92.9%. OARs were met in all patients but one with a liver metastasis close to the stomach (D0.1cc=22.8Gy), and the duodenum (D0.1cc=26.9Gy, D10cc=21.0Gy). After RT, 2 patients experienced grade 1 fatigue, and 1 experienced grade 2 vomiting. Median time from RT to surgery was 5 days (5-8). Median surgery duration, in room time, and hospital stay were 238 (52-605) minutes, 345 (149-697) minutes, and 6 (2-14) days respectively. No intraoperative or postoperative complications were attributed to RT. Day 30 complication and Day 90 mortality rates were 8.3% (one grade 1 abdominal pain) and 0% respectively. All the 4/5 surgeons who completed the survey had a negative opinion of the RT impact on the surgical procedure, but after performing at least one case, they all became confident. Surgeons reported no increase in blood loss, surgery time, and hospital stay related to RT, though one noted increased per-operative fibrosis (Figure 2).