ESTRO meets Asia 2024 - Abstract Book

S208

Interdisciplinary – Lower GI

ESTRO meets Asia 2024

endpoints were acute toxicity (≤ 3 months) according to Common Terminology Criteria for Adverse Events version 5.0 and to asses HT tolerance. Treatment safety analyses were performed for all treated patients.

Results:

Thirty-one patients (91.2%) received 2 HT sessions and 3 patients (8.8%) received 1 HT session. Overall, 60 (98.4%) patients pathological CR results were obtained. Thirteen patients (39.5%) achieved pathological CR in the radiochemotherapy + HT group, compared to 29.5% (n=8) in the radiochemotherapy group, a 10% clinical relevant difference. There was no significant difference in acute toxicities between groups ( P =1.00) and no significant difference in grade ≥ 3 acute toxicity ( P =0.51). The most common reported acute toxicities grade 1 consisted of diarrhea (n=18, 29.5%), rectal pain (n=12, 19.7%), dermatitis radiation (n=10, 16.4%), and nausea (n=10, 16.4%). Grade 2 acute toxicities most reported were diarrhea (n=8, 13.1%), dermatitis radiation (n=7, 11.5%), and rectal mucositis (n=7, 11.5%). Dermatitis radiation grade 3 (n=5, 8.2%) was most reported. No grade 4-5 acute toxicity was observed. Only one patient (2.9%) developed a grade 1 burn related to HT. During HT treatments 24 patients (70.6%) experienced general mild pain, 12 patients (35.3%) warm skin, 7 patients (20.6%) bolus pressure, and 5 patients (14.7%) mild discomfort. Figure 1 illustrates the locations of patients complaints during the HT sessions. Furthermore, nine patients (14.8%) developed postoperative complications, 6 (9.8%) in the radiochemotherapy + HT group, and 3 (4.9%) in the radiochemotherapy group ( P =0.72).