Scanning proton beam therapy reduces normal tissue exposure in pelvic radiotherapy for anal cancer

An inter-comparison planning study between photon beam therapy (IMRT) and scanning proton beam therapy (SPBT) for squamous cell carcinoma of the anus (SCCA) is presented. SPBT plans offer significant reduction (>50%, P = 0.008) in doses to small bowel, and bone marrow thereby offering the potential to reduce bowel and hemotoxicities.