How do you prevent non-healing ulcer when treating patients with cutaneous SCC of the distal lower extremity who have peripheral vascular disease?  

@Robin G. Smith points are well taken  but he does not mention dose fractionation. For most skin cancers, I usually treated with a fairly short course of RT , e.g.  400×10, but not in this situation, where a longer course, e.g. 60-70 Gy in 2 Gy fxs may be desirable. 

In my experience, here is no perfect answer.  Making sure all factors, as best as possible, are attended to: the patient has quit or reduced smoking during the treatment and is getting active support to do so, blood sugar (diabetes) is under control, foot care is being delivered if this is an i...