ESTRO 2025 - Abstract Book

S1181

Clinical – Lower GI

ESTRO 2025

pathological response, and 1 had only microscopic residual disease. The treatment regimen was well tolerated, with no grade 3 or higher late toxicities reported. At the last follow-up, 8 patients were disease-free, while 2 had local recurrence, including 1 with distant metastases. Two-year disease-free survival was 83% (95% CI: 67%-100%).

Figure 1

Conclusion: Our preliminary findings suggest that an accelerated hyperfractionated chemoradiation regimen is feasible and effective in patients with rectal cancer and IBD, with manageable toxicity. These results support the use of this approach in high-risk populations, including those with prior abdominal-pelvic surgery or comorbidities. Further studies with larger cohorts and longer follow-up are needed to validate these findings and explore broader applicability.

Keywords: rectal cancer, hyperfractionated accelerated

1954

Digital Poster Long-term clinical outcomes following intensified total neoadjuvant therapy for locally advanced rectal cancer: a single-centre experience Carolina Gentili, Francesca De Felice, Elisa Vitti, Maura Anna Lanzilao, Alessia Delle Donne, Carlo Guglielmo Cattaneo, Miriam Tomaciello, Francesco Marampon, Daniela Musio, Giuseppe Minniti Radiation Oncology, Sapienza University, Rome, Italy Purpose/Objective: Total neoadjuvant therapy (TNT) strategy in patients with locally advanced rectal cancer (LARC) offers the option of better oncological outcomes. Our aim was to assess long-term clinical outcomes in LARC patients managed with intensified TNT and followed up in an Italian referral cancer center. Material/Methods: Patients with non-metastatic LARC were treated with an intensified TNT approach. Based on performance status, age, comorbidities and RAS-BRAF status, patients received induction chemotherapy (5-fluorouracil, leucovorin, oxaliplatin with/without irinotecan and/or bevacizumab/panitumumab/cetuximab) followed by chemoradiotherapy (CRT) with 50.4/54 Gy and concomitant 5-fluorouracil and oxaliplatin according to our previous trial. Surgery was