Radiation fibrosis in my lung popped up on a PET scan in November, a latent side effect. I then thought, "Ah, ha, that is why I have had periods of labored breathing going up/down the steps." But, really I can't complain as exercise really helps - yoga, stationery bike, rowing machine. If it gets no worse I will be grateful, but who knows for certain it won't get worse? Scary thought. cedar75's radiation oncologist noting that more long term effects were being reported was of interest to me. My radiation oncologist pretty much dismissed this question with a vague, general reply about how common it was. I did see an article that lung fibrosis was more common in thin women who had had a mastectomy (that's me) and those who had been on tamoxifen. Another article mentioned that shorter treatments with higher dosages would require additional training/monitoring. I guess time will tell.