I need help getting information about developing a enlarged thyroid while undergoing radiation treatment for breast cancer. The right side of my thyroid is enlarged after completing 24 out of 33 treatments. The Rad Oncologist says it is not related to the treatment and I disagree. He has scheduled an ultrasound but it will not be done for two weeks. I am considering stopping my radiation treatment until I get more information. Can anyone help me with information. Thank you....Marilyn