In a thin patient with anal cancer, do you use bolus over the inguinal nodal volume when treating with an IMRT technique?  

Rarely, only if the tumor is involving the skin, but I always sue 6MV photons and more than enough dose. The skin gets plenty of dose with IMRT and 6MV photons. When there is gross node in a thin patient, it doesn't add morbidity to do so, however. The only inguinal recurrence I have ever had, gross...

We don’t use bolus for prophylactic nodal RT but if gross node within 5 mm if skin then we do add local bolus