What radiation dose, fractionation and volume would you use in an elderly patient with localized extensive anorectal malignant melanoma status post laparoscopic APR?

What a great question! This has come up a couple of times in my clinical practice. For anorectal mucosal melanoma that is completely excised and < 7 mm depth of invasion, I have done surface intra-cavitary brachytherapy with a Capri cylinder.

For deeper lesions or LN involvement, I have used photon...