When treating anal cancer with VMAT or IMRT, do you use bolus?

I bolus the primary if I can see it on inspection in the treatment position. I do not usually use bolus for the inguinals unless there has been an excision or the tumor is involving the skin. In that case, I give a 5cm margin on the scar with bolus. I have seen several cases in the distant past of d...

I don't use bolus unless there is frank skin involvement, either peri-anal or over an involved node.

The idea of bolus (sometimes virtual) is not only to cover visible lesions on skin but also to create flash to avoid geographical miss with set up error and swelling.

I agree with the above comments regarding the use of bolus to cover visible tumor with margin. Questions that arise are where to crop the PTV, how much margin to place around skin extension of tumor and how to handle anal SCCA in complex fistula disease.

-- Would one keep the PTV at the skin border...