Anal Cancer in the Era of Dose Painted Intensity Modulated Radiation Therapy: Implications for Regional Nodal Therapy.

Since the initial development of 5-fluorouracil and mitomycin as a standard of care platform for definitive anal cancer chemoradiotherapy, multiple studies have evaluated the optimal chemotherapy regimen, and radiotherapy technique. Refinements in treatment technique have taken place during an era of improved diagnostic imaging, including incorporation of FDG-PET, with implications for a possible stage migration effect. This has introduced an opportunity to develop stage-specific recommendations for primary tumor, involved nodal, and elective nodal irradiation dose. Elective nodal irradiation remains standard given the low rates of elective nodal failure with current practice, although may be subject to evolving controversy for patients with early stage disease. In this review, development of the current standard of care for anal cancer chemoradiotherapy is reviewed in the context of modern staging and dose-painted radiotherapy treatment techniques.