ESTRO 2024 - Abstract Book

S1534

Clinical - Lower GI

ESTRO 2024

Conclusion:

ICT with FOLFIRINOX increased 1-year organ preservation up to 71.7% in a selective approach for rectal cancer at the cost of increased but manageable toxicity.

Keywords: Organ preservation, Rectal cancer, Radiotherapy

2072

Digital Poster

Radiation boost to the enlarged lateral nodes in patients receiving radiotherapy for rectal cancer

Lucyna Pietrzak 1 , Anna Hołdakowska 2 , Andrzej Rutkowski 3 , Tomasz Olesiński 4 , Anna Cencelewicz-Lesikow 4 , Krzysztof Bujko 5 1 Maria Sklodowska-Curie National Research Institute of Oncology, Radiotherapy, Warsaw, Poland. 2 Maria Sklodowska-Curie National Research Institute of Oncology, Radiology, Warsaw, Poland. 3 Maria Sklodowska-Curie National Research Institute of Oncology, Gastroenterological Oncology, Warsaw, Poland. 4 Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland, Gastroenterological Oncology, Warsaw, Poland. 5 Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland, Radiotherapy, Warsaw, Poland

Purpose/Objective:

In Western countries, resection of lateral nodes is usually not performed following preoperative radiotherapy. However, recurrence in the site of the initially enlarged lateral nodes was reported in 19.5% of patients at 5 years in a large multicentre study. Herein we present a retrospective evaluation of the utility of radiation boost to enlarged lateral nodes.

Material/Methods:

Between September 2017 and February 2020, 22 patients with rectal cancer having enlarged lateral nodes underwent preoperative short-course radiotherapy (5 x 5 Gy) with boost to these nodes and 6 weeks of consolidation chemotherapy with De Gramont schedule (continuous infusion of 5-FU and bolus leucovorin). All patients had baseline high-resolution MRI. Median diameter of lateral nodes was 10 mm (range 5-15) in the short axis. Radiation boost was given in a single fraction of 4 Gy immediately after the completion of the 5 × 5 Gy dose (n=7) or using simultaneous integrated boost technique; 5 × 6 Gy to the enlarged lateral node(s) and 5 × 5 Gy to the remaining of the irradiated volume (n=15).

Results:

There was no grade 3+ acute toxicity related to preoperative radio- and chemotherapy. Six patients did not undergo tumour resection: one because of dissemination prior to a planned surgery, three had tumour deemed unresectable at surgery and two underwent watch&wait strategy and two had sustained a clinical complete