Hi, I am 54 and was told that I have dense breasts, as well. I have a mammogram every year because [breast and other] cancers run in my family. I know that seeing your doctors, especially when you have had specific issues is vitally important. I have not been diagnosed with any issues with my breasts, other than being told that they are dense, but due to a motorcycle accident years ago I have had a lot of experience with doctors and other therapists over the become a believer that if you don't feel good about one [or more!] of your doctors or therapists, there is usually a good reason for this. It might be that they don't know as much as they would have you believe, maybe they have made a false call about something and ae trying to cover-up their mistake, or they simply don't know what they are doing.

It is important to have a good working relationship with your health care team. Once every five years probably doesnt provide any useful data, especially since your oncologist is doing one every six months. Talk to your oncologist about your concern. Should it be necessary for you to undergo more radiation, (unlikely), I'm sure another radiation doctor can be found.