>Nuclear technology cures countless cancer patients every day - and a radiation dose given for radiotherapy in hospital is no different in principle to a similar dose received in the environment.
From http://www.cancer.gov/cancertopics/coping/radiation-therapy-... :
"Late side effects may first occur 6 or more months after radiation therapy is over. They vary by the part of your body that was treated and the dose of radiation you received. Late side effects may include infertility, joint problems, lymphedema, mouth problems, and secondary cancer."