Ditto to what Brian said. There are two different questions here... treatment for cancer, and HBO treatments to prevent osteonecrosis and promote tissue healing.

I would have elaborated on my answer but things have been a bit harried here as of late. A friend finally passed from a brutal death from peritoneal cancer (she was 60 lbs at the end) and my dad is in the hospital.

In regards to one of the postings a fear of O2 feeding cancer... it's actually the opposite as I believe Eric's link may infer (haven't checked it) most cancers prefer a hypoxic environment. That's one of the reasons studies show that smokers - generally do more poorly during, and after rads, and in regards to survival rates. They also suggest higher survival rates amongst people who walked for short periods (I walked my dog minimum once a day - usually twice - for 20-30 minutes) during treatment. I missed maybe three days total during and after rads.

This of course increases O2 intake and perforation of tissues and helps fight cancer if it is a cancer that prefers a hypoxic environment.