title: [Follow-up of high-risk patients with differentiated thyroid cancer without persistent disease after initial therapy].
abstract: This study evaluated the follow-up of high-risk patients with thyroid cancer after initial therapy. A total of 125 high-risk patients (tumor >4 cm and/or extrathyroid invasion and/or lymph node metastases, and age >45 years), with complete resection of the tumor, were selected. All patients underwent total thyroidectomy and ablation with (131)I[3.7-5.5 GBq (100-150 mCi)]. Eighteen patients (14.8%) presenting metastases on post-dose whole-body scan (RxWBS) were excluded. The negative predictive value of stimulated Tg < or =1 ng/ml in combination with neck US during first assessment (612 mo. after ablative therapy) was 96.2% for the absence of recurrence up to 5 years. This value increased to 98.7% when adding WBS performed with 185 MBq (5 mCi) (131)I (DxWBS). The positive predictive value (PPV) of stimulated Tg >1 ng/ml was 52% for the detection of the presence of metastases up to 5 years; however, considering only patients with initially negative DxWBS and US, the PPV was 19% (9% if Tg of 110 ng/ml vs. 40% if Tg >10 ng/ml). Tg levels decreased spontaneously in patients with stimulated Tg >1 ng/ml during first assessment, negative US and DxWBS, and no recurrence during follow-up, with Tg being undetectable in half these patients at the end of 5 years. Twenty patients presented uptake in the thyroid bed upon DxWBS during the first year after ablative therapy, with stimulated Tg and US being negative, and were not treated with 131I; these patients did not relapse and no uptake on DxWBS was observed in 60% after 5 years. Recurrence after 5 years was only 1.3% in patients without apparent disease (negative US and DxWBS) and stimulated Tg <1 ng/ml. An algorithm for the follow-up of high-risk patients after initial therapy is presented in this study.
authors.affiliation: Serviço de Endocrinologia, Departamento de Tireóide, Santa Casa de Belo Horizonte, MG. pedrorosario@globo.com
authors.forename: Pedro Weslley S
authors.initials: PW
authors.lastname: do Rosário
authors.forename: Michelle A Ribeiro
authors.initials: MA
authors.lastname: Borges
authors.forename: Maria Flávia Gatti
authors.initials: MF
authors.lastname: Alves
authors.forename: Saulo
authors.initials: S
authors.lastname: Purisch
authors.forename: Eduardo Lanza
authors.initials: EL
authors.lastname: Padrão
authors.forename: Leonardo Lamego
authors.initials: LL
authors.lastname: Rezende
authors.forename: Alvaro Luís
authors.initials: AL
authors.lastname: Barroso
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000188:drug therapy / Q000601:surgery*; D002291:Carcinoma, Papillary / Q000188:drug therapy / Q000601:surgery*; D017115:Catheter Ablation; D003266:Continuity of Patient Care; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015592:Immunoradiometric Assay; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D013954:Thyroglobulin / Q000097:blood; D013964:Thyroid Neoplasms / Q000188:drug therapy / Q000601:surgery*; D013965:Thyroidectomy; D013974:Thyroxine / Q000032:analysis; D016896:Treatment Outcome; D051598:Whole Body Imaging
chemical_list: D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D013954:Thyroglobulin; D013974:Thyroxine