ESTRO 2024 - Abstract Book

S2218

Clinical - Upper GI

ESTRO 2024

Material/Methods:

The study started in May 2021. Enrolment will last 36 months, followed by 12 months of follow-up for a duration of 4 years and 50 patients to enroll. The inclusion criteria are: surgically treated T1-T4 adenocarcinoma with or without prior ChT and close (<2.5mm)/positive resection margin and/or N1 at lymphadenectomy, ECOG PS <2, estimated life expectancy > 6 months. The exclusion criteria are: metastatic disease, biliary tract or neuroendocrine tumors, history of malignancies except for non-melanoma cutaneous tumors. The primary endpoint is local relapse rate. The secondary endpoints are disease-free survival, overall survival, patterns of failure, acute and late toxicity and clinical-pathological factors related to disease recurrence. SBRT is administered within 4-6 weeks from surgery and adjuvant ChT. We performed 2 volumes in 5 fractions: CTV1 (40 Gy) which covers clips+isotropic 5mm expansion edited on anatomic barriers and CTV2 (30 Gy) which covers CTV1+ anisotropic 10-15 mm expansion edited on anatomic barriers. Toxicities were recorded according to CTCAE v.5.0.

Results:

This preliminary toxicity analysis was focused on 42 patients. Neoadjuvant ChT was performed in 19 patients (45.2%) and 18 (42.8%) underwent adjuvant ChT. Surgery consisted of pancreatoduodenectomy (24 patients, 57%), distal (11,26%) and total pancreatectomy (7,16.6%). All toxicities are shown in Table 1. No patients experienced G3 toxicity. The most frequent toxicities during SBRT were: asthenia (G1, 11.9%), nausea (G1, 14.2%; G2, 9.5%), abdominal pain (G1, 11.9%; G2, 2.4%) and diarrhea (G1, 11.9%; G2, 2.4%). After 3 and 6 months, abdominal pain (16.6%) and diarrhea (11.9%) remained the most observed G1-G2 toxicities. After 1 year, we recorded G2 abdominal pain (4.7%) and G1 diarrhea (2.4%). After 6 and 12 months we observed due cases of G2 malabsorption returned after therapy with pancrealipase