ESTRO 2024 - Abstract Book

S3495

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

Conclusion:

This study demonstrates that simple “eye-guided” electron beam RT in perianal SCC results in excellent LC for T1 tumours with only two LF (8%) while for T2 tumours LC was less favourable. No signs of a geographical miss were found in patients with LF. However, other reasons may explain the number of LF in the study. First, two LF are diagnosed after 60 months or longer follow-up and it could be argued that they are new primaries rather than true LF. Second, a majority of all local failures are diagnosed in patients with T2 tumours and could be attributed to the lack of knowledge regarding the exact dose-response for these tumours as well as knowledge regarding individual patient-related factors that may contribute to radioresistance.

Keywords: Electron beam, perianal squamous cell carsinoma