Are they treating with antibiotics...? a bad smell is bad... usually a sign the infection is progressing... all in all it's best to finish treatment first but... make sure all your ducks are lined up. Ask now... what is do the have planned if the radiation doesn't work and make sure it's in place at the end of treatment. The problem with stuff like this is after radiation it takes a while to heal, and surgeons don't like working with radiated skin... it doesn't heal all that well or takes far too long, and that again leaves the patient open to infection. etc... Start asking now and make sure you get an answer, or hear that they have a plan in place. good luck and take care.