Breast Cancer: Tight chest wall following radiation

Last June 2022, after radiation therapy for 6 weeks daily to my left chest wall, (following breast cancer surgery in February) I developed severe tightening in my entire chest, making it difficult to get a deep breath without pushing against what feels like a tight band wrapped around me (24/7 all day). I went to Physical Therapy to help with regaining movement around the surgical area. In August, I started Myofascial Release Therapy 2x a week (interrupted in September and October), then starting up again in November. In March, after nearly 5 months of MRT therapy and no relief, we took a break. My radiation oncologist suggested we try the Barometric Oxygen Therapy for 6 weeks to see if that might help loosen up the fascia. That treatment did not change anything for me. I am uncomfortable daily with this tight band, and not sure where to turn for relief. Is there any of kind of treatment that anyone knows about that might help me. Even with the uncomfortable tightness, I swim regularly and participate in 2 Qijong classes a week and continue to stretch. Thank you for any suggestions. Nancy