Metastatic papillary carcinoma was diagnosed in a 42-year-old woman. The cancer had invaded out of the gland and was present in many lymph nodes. After her surgical procedure, she was advised to have radioiodine. However, the patient had total renal failure and was on dialysis. Studies were carried out using a tracer dose of 2 mCi of radioiodine, demonstrating that approximately 60% of the radioactivity in the body was removed with each dialysis. Calculations indicated that a meaningful dose of radiation could be delivered to residual thyroid and metastases with 100 mCi of radioiodine and the total body radiation would be < 100 rad delivered over several days. Based on these analyses, she received 100 mCi of I-131 on two separate occasions and on follow-up scan, clinical evaluation and thyroglobulin measurement is free of disease.