By Grégoire Laurent Delanghe, MD

GEC-ESTRO Best Junior Presentation Award

ESTRO 2025 Congress Report | Brachytherapy track

 

At ESTRO 2026, I presented a retrospective analysis I conducted with Dr Abel Cordoba (France) and colleagues from the Oscar Lambret Comprehensive Cancer Centre, in which we evaluated 92 patients with anal canal carcinoma who had been treated with external beam radiotherapy (EBRT) followed by an interstitial brachytherapy boost.

 

The study was focused on a highly selected population, with 90% of patients presenting with T1-2 disease and only 14% with nodal involvement. Median prescription dose was 45Gy for EBRT and 12Gy for brachytherapy. After a median follow-up of more than five years, outcomes were excellent, with a three-year cumulative incidence of local recurrence of 5.7%, a disease-free survival rate of 82.4%, and a colostomy-free survival rate of 82.3%.

 

A key objective was to compare pulse-dose-rate (PDR) and high-dose-rate (HDR) brachytherapy. In this series, the choice of technique was determined only by the treatment period; PDR was used until 2021, and HDR was introduced after that, making these populations comparable. No significant differences were observed between the two techniques regarding local control or disease-free or colostomy-free survival rates. Toxicity remained acceptable overall, with only four patients requiring a definitive colostomy because of treatment-related complications.

These findings confirm the value of an interstitial brachytherapy boost in carefully selected patients with early-stage anal canal carcinoma, and emphasise the need to consider dose de-escalation for these patients. Importantly, they also support the ongoing transition from PDR to HDR brachytherapy, which offers practical advantages while maintaining comparable oncological outcomes and tolerance.

In a rare disease for which prospective randomised trials are difficult to conduct, large contemporary institutional series such as this provide valuable evidence to guide clinical practice and support the increasing use of HDR brachytherapy.

 

 

 

Grégoire Laurent Delanghe, MD

University Department of Radiation Oncology

Oscar Lambret Comprehensive Cancer Centre

Lille, France.

Email: gr-laurent@o-lambret.fr