What dose should you treat the anal canal after excision of a T1 anal cancer with positive margins?

I would, under no circumstance, treat this patient to a dose of 50 Gy. For a T1 tumor (even unresected) that is likely an excessive dose. Keep in mind that the initial reports of RT and chemo used a dose of about 30 Gy with complete pathological response. There are data to suggest that doses of abou...