Inclusion criteria | |
•Radical intent external beam radiotherapy treatment for primary anal squamous cell carcinoma, with or without concomitant chemotherapy | |
•Radiotherapy delivered using modern radiotherapy techniques (3D-CRT, IMRT or VMAT) | |
Exclusion criteria | |
•Palliative treatment | |
•Prior pelvic radiotherapy | |
•Brachytherapy (either primary or as boost treatment) |