<prompt> I131 is the preferred treatment for:ChildrenYoung adults with recent onset Graves diseaseElderly patients with ischemic hea diseasePregnant women  <response>: Ref: KDT 6e p253 I131 is contra-indicated in children and young adults because if hypothyroidism develops in response to radioactive iodine, it is permanent. Use of radioactive iodine is contra-indicated in pregnancy. In ischemic hea disease patients, surgery should be avoided. I131 therapy is a good alternative in such patients. 