I have read that somewhere about HBO as well. However, this was on Univ. of Penn's website:
RELATIONSHIP OF HBO TO CANCER:

"To date there is no evidence linking HBO therapy with increased risk of tumor formation. Davis and Hunt in 1988 studied 75 animals treated with HBO and found no increase or progression of tumors in HBO group compared with controls."

There is a phase II clinical trial at UoPenn "...validate the model and assess the efficacy of HB02 therapy for improving outcome. The focus will be to determine the patho-physiological basis for heightened surgical risk among post-radiation head and neck patients and the efficacy of hyperbaric oxygen (HB02) therapy for improving outcome." The study won't be completed until Aug. 2005.

I found it interesting also that at least 2 major CCC's have in house HBO.

Infections are pretty common post Tx because of the low WBC. No infections can be taken lightly but bone infections are probably the more serious. They can lead to Osteoradianecrosis because the capillaries in the bones in the radiated field are compromised and it is harder for the body to fight infections in those areas. There are high powered alternatives to the (peni)cillin classes of antibiotics. Cipro comes to mind. It is good that you are on top of this.