I've seen reports that say HBOT doesn't cause or promote cancer, but it has been suggested previously that it's possible through angiogenesis. Even still, my current doctors waited until I was clear of cancer by scan, after 6 months, to do HBOT treatments. On another note, I also had HBOT several years ago, 3 months after radiation, no scan yet then, and had a recurrence a month later, coincidently or not. There have been other studies with HBOT with chemo, which showed some treatment promise when added, but maybe not so with radiation, so there may be contradictions with this, and others, for this type of treatment, so as suggested, see what the doctors say.

Good luck with everything.