Managing thyroid cancer without thyroxine withdrawal.
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.
Rosário
Pedro Weslley S do
PW
Department of Thyroid, Santa Casa de Belo Horizonte, MG. pedrorosario@globo.com
Vasconcelos
Flavio P J
FP
Cardoso
Ludmilla D
LD
Lauria
Márcio W
MW
Rezende
Leonardo L
LL
Padrão
Eduardo L
EL
Barroso
Alvaro L
AL
Guimarães
Valéria C
VC
Purisch
Saulo
S
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
D008078:Cholesterol, LDL; D007457:Iodine Radioisotopes; D013972:Thyrotropin; D013954:Thyroglobulin; D003402:Creatine Kinase; D013974:Thyroxine