Differentiated thyroid cancer: comparison of therapeutic iodine 131 biological elimination after discontinuation of levothyroxine versus administration of recombinant human thyrotropin

摘要: The biological elimination of therapeutic131I in patients with differentiated thyroid cancer (DTC), post total or near-total thyroidectomy, was compared after withholding levothyroxine suppression against administration recombinant human thyrotropin without stopping levothyroxine. In 163 (group G1) withheld before131I therapy: 138 the tumor limited to bed G1.1) and 25 metastases were present G1.2). A second group (G2; n = 28) received131I therapy Mean retained131I activity (as a percentage administered dose) 5%-29% G1.1), 20%-43% G1.2) 1 %-17% G2). effective half-life of131I 0.59-0.69 days 0.87-1.22 0.38-0.44 conclusion, use prepare for with131I shortens its reduces retained preparation discontinuation suppression.