title: Managing thyroid cancer without thyroxine withdrawal.
abstract: Thyroxine (T4) withdrawal or recombinant TSH is used for the stimulation of thyroglobulin (Tg), whole-body scanning (WBS) and iodine-131 treatment in patients with thyroid carcinoma. This study evaluated the T4 dose reduction protocol as an alternative for patients' preparation. Fifty-one patients were submitted to total T4 withdrawal for WBS and Tg measurement. T4 treatment was then resumed and maintained until TSH reached levels < 0.3 mIU/l. The T4 dose was then decreased to 0.8 microg/kg/day and TSH was measured weekly. Tg was assayed when TSH was > 30 mIU/l. Patients diagnosed with the disease upon initial evaluation were treated. We also evaluated the clinical and laboratory changes observed for both preparations. Using the reduced dose protocol, TSH levels > 30 mIU/l were reached within 6 and 8 weeks in 84.6 and 100% of the patients, respectively. T4 withdrawal was associated with more common symptoms of hypothyroidism and elevation of creatine kinase (CK) and LDL cholesterol. The T4 dose reduction protocol proved to be useful for Tg stimulation and ablative therapy, without the complication of severe hypothyroidism or the cost of recombinant TSH.
authors.affiliation: Department of Thyroid, Santa Casa de Belo Horizonte, MG. pedrorosario@globo.com
authors.forename: Pedro Weslley S do
authors.initials: PW
authors.lastname: Rosário
authors.forename: Flavio P J
authors.initials: FP
authors.lastname: Vasconcelos
authors.forename: Ludmilla D
authors.initials: LD
authors.lastname: Cardoso
authors.forename: Márcio W
authors.initials: MW
authors.lastname: Lauria
authors.forename: Leonardo L
authors.initials: LL
authors.lastname: Rezende
authors.forename: Eduardo L
authors.initials: EL
authors.lastname: Padrão
authors.forename: Alvaro L
authors.initials: AL
authors.lastname: Barroso
authors.forename: Valéria C
authors.initials: VC
authors.lastname: Guimarães
authors.forename: Saulo
authors.initials: S
authors.lastname: Purisch
mesh_terms: D000328:Adult; D002277:Carcinoma / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery; D016022:Case-Control Studies; D008078:Cholesterol, LDL / Q000097:blood; D003402:Creatine Kinase / Q000032:analysis / Q000097:blood; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013954:Thyroglobulin / Q000096:biosynthesis / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood / Q000532:radiotherapy* / Q000601:surgery; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome; D051598:Whole Body Imaging
chemical_list: D008078:Cholesterol, LDL; D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013954:Thyroglobulin; D003402:Creatine Kinase; D013974:Thyroxine