2012年澳大利亚胃肠研究学会肛管癌调强放疗靶区勾画指南

With the advent of computed tomography (CT) planning and conformal radiation techniques including intensity-modulated radiotherapy (IMRT), comes the prerequisite for accurate and consistent contouring of target volumes.

Conformal radiotherapy for anal cancer allows the ability to spare surrounding organs at risk (OAR). Normal tissues such as small bowel, femoral heads, perineum, and external genitalia often receive high doses of radiation with more conventional techniques, which can result in significant acute and late toxicity. The use of IMRT provides an opportunity to spare OAR and to reduce toxicity in anal cancer patients.

The implementation of IMRT requires a clear understanding of target volume definition for the complex elective nodal regions in anal cancer. During the early conduct of the Radiation Therapy Oncology Group (RTOG) 0529 Phase II study investigating IMRT for anal cancer, it became necessary to create an atlas because many initial target volumes submitted for quality assurance required contouring revision. However, this atlas provided contouring guidance for elective nodal volumes only and did not provide instruction in the contouring of gross disease and OAR.

As such, an international workshop was convened at the 2010 Australasian Gastrointestinal Trials Group (AGITG) annual meeting to develop detailed contouring and planning guidelines for the IMRT treatment of anal cancer, supplemented by a highresolution atlas. This article reports the AGITG recommendations.