Anal carcinoma is a disease in which modern therapy is reasonably successful in achieving tumour control/cure. Both acute and late side effects are substantial. Proton radiotherapy is hypothesised to have the potential to decrease the incidence/severity of some acute side effects from certain organs at risk e.g. bone marrow and intraperitoneal bowel. By sparing the dose to these organs it is also possible that late effects might be less evident. Sparing of the bone marrow may lead to fewer septic events and dose reductions of chemotherapy which may, as a consequence, improve tumour control. The primary aim of this study is to find ways to decrease acute side effects primarily to alleviate some discomfort from the patient during and after a usually painful treatment experience. It has also been concluded by others that reduction of acute side effects is a relevant aim and end point for the evaluation of new treatment techniques and both patient reported and physician reported data are assessed
Dosimetric studies suggest that radiotherapy with protons has a potential to reduce side effects compared to treatment with photons for patients with anal carcinoma (AC). There are so far no studies comparing these treatment techniques in a randomised setting. The aim of this study is to compare side effects following photon therapy versus proton therapy within the framework of a randomised controlled trial.