What dose and fractionation would you recommend for treating the primary site of a patient with metastatic anal melanoma?

There is little data that defines the best approach to radiotherapy for the primary tumor in mucosal melanoma of the anal canal. In the context of metastases, a hypofractionated regimen seems most appropriate. Investigators from MDACC have published on a regimen of 30 Gy in 5 fractions given twice a week, and rectal adenocarcinoma studies have shown that 25 Gy in 5 fractions given daily is well tolerated in the neoadjuvant setting. If radiotherapy to the primary tumor were deemed appropriate, I would consider using one of these regimens.