Overview of Radiation Treatment Volume Variations in Anal Cancer Contouring Guidelines

Recently, an Eastern Cooperative Oncology Group - American College of Radiology Imaging Network guideline was published to describe recommended treatment volumes in patients with a diagnosis of early-stage anal cancer. There are notable differences in descriptions for both the primary target and elective nodal volumes when comparing this guideline with established guidelines from the United Kingdom National Cancer Research Institute, Australasian Gastrointestinal Trials Group, and Radiation Therapy Oncology Group. Support for these volume differences is based on retrospective data, but ultimately, prospective data from ongoing clinical trials are needed to validate these approaches.