Yes. My husband has thyroid issues since his radiation treatment for oral cancer in 2001-2002. They discovered his thyroid is overactive with one "hot" node causing it. That one node they suspect was damaged from the radiation. He takes a small amount of medication to treat it. They suggested ablating the whole thyroid and replace completely the hormones it produces which is easier to maintain I guess. He chose to not do that and takes a small amount of medication to treat his overactive thyroid. About two months after his radiation was completed he was sent to the ER with a racing heart and they thought he was having cardiac issues. He was not. His undiagnosed overactive thyroid condition caused by the radiation was causing it.