Undetectable thyroglobulin after total thyroidectomy in patients with low- and intermediate-risk papillary thyroid cancer— is there a need for radioactive iodine therapy?

Background The efficacy of radioactive iodine therapy (RAI) in patients who have an undetectable thyroglobulin (Tg) level after total thyroidectomy in well-differentiated papillary thyroid cancer (PTC) is questionable. The objectives of this study were to report the risk of recurrence in patients with PTC who had an undetectable Tg level after total thyroidectomy managed with postoperative RAI and without RAI. Methods After approval by the institutional review board, 751 consecutive patients who had total thyroidectomy for PTC as well as postoperative Tg measurement were identified from our institutional database of 1163 patients treated for well-differentiated thyroid carcinoma at Memorial Sloan Kettering Cancer Center between 1999 and 2005. Of these, 424 patients had an undetectable postoperative Tg (defined as a Tg