Hi Bravo, This was the exact thing I was very concerned about. YES there is a new method now called Breast Radiotherpay with Deep Inspiration Breath Hold (DIBH) where we the patient hold our breath when told and hold it tell told to let go (20 seconds) and this means our lungs and hear are stretched longwise and also pulled away from the breast wall. here's a Wikipedia explanation. https://en.wikipedia.org/wiki/Deep_inspiration_breath-hold. My oncologist confirmed my research that they do use it particularly with women with left breast cancer. Its wonderful all the new research they are doing and have done bringing things like DIBH to us to lessen the damage to our organs. Best of luck. I start radiation on 26/5. for 30 sessions.