Does undetectable basal Tg measured with a highly sensitive assay in the absence of antibodies and combined with normal ultrasonography ensure the absence of disease in patients treated for thyroid carcinoma?

Pedro Weslley Rosário, Augusto Flávio Campos Mineiro Filho
2012 Arquivos brasileiros de endocrinologia e metabologia  
It has been proposed that, in patients treated for well-differentiated thyroid carcinoma, undetectable basal thyroglobulin (Tg) levels measured with a highly sensitive assay in the absence of anti-thyroglobulin antibodies (TgAb) and combined with negative neck ultrasonography (US) ensured the absence of disease. We report a series of five patients with well-differentiated (papillary) carcinoma submitted to total thyroidectomy with apparently complete tumor resection, followed by remnant
more » ... with 131I (100-150 mCi), who had no distant metastases upon initial post-therapy whole-body scanning. When tumor recurrence or persistence was detected, these patients presented undetectable basal Tg (0.1 ng/mL) in the absence of TgAb, and US showed no anomalies. Two patients had lymph node metastases, one had mediastinal metastases, bone involvement was observed in one patient, and local recurrence in one. We conclude that further studies are needed to define in which patients undetectable basal Tg (negative TgAb) combined with negative US is sufficient, and no additional tests are required.
doi:10.1590/s0004-27302012000200009 pmid:22584569 fatcat:pdxawe6e2ncmrnofxaxlmketxu