I'm just a year and a half out from my radiation following tongue cancer surgery. I'm currently seeing an OT for Myofacial Release Massage. I had scar tissue that refused to budge as well as fibrosis from radiation. I have an hour of this massage once a week. I have regained a lot of range of motion and flexibility. Maybe you could see a Myofacial Release Massage therapist in your area and see if that is something that will help you, too.