RESUMEN
BACKGROUND: Follow-up consisting of the measurement of nonstimulated serum thyroglobulin (Tg) combined with neck ultrasonography is recommended for patients with papillary thyroid carcinoma without indication for radioiodine ablation. There is no recommendation of thyrotropin suppression during this follow-up. New-generation Tg assays have been increasingly used, but few studies involve patients submitted only to thyroidectomy and they have several limitations. The objective of this prospective study was to define expected concentrations of nonstimulated Tg measured with a second-generation assay after total thyroidectomy in the absence of tumor. METHODS: Serum Tg was measured using a second-generation assay in 69 patients without tumor and serum thyrotropin between 0.5 and 2 mIU/L, 3, 6, 12, and 24 months after total thyroidectomy. All patients had undetectable anti-Tg antibodies. RESULTS: Serum Tg was undetectable in 44.4%, 57%, 62.5%, and 62.1% of the patients 3, 6, 12, and 24 months after thyroidectomy, respectively, and was ≤0.5 ng/mL in 60.3%, 80%, 90.6%, and 90.9% of patients. All patients had a Tg≤2 ng/mL 6 months after thyroidectomy, and 97% had a Tg≤1 ng/mL 24 months after surgery. There was no case of Tg conversion from undetectable to detectable and none of the patients presented an increase in Tg. CONCLUSIONS: An important decline in serum Tg occurred between 3 and 6 months after total thyroidectomy. One year after surgery, Tg was undetectable in approximately 60% of the patients and was ≤2 ng/mL in all of them.
Asunto(s)
Carcinoma Neuroendocrino/sangre , Carcinoma/sangre , Recurrencia Local de Neoplasia/sangre , Tiroglobulina/sangre , Neoplasias de la Tiroides/sangre , Nódulo Tiroideo/sangre , Tiroidectomía , Adulto , Anciano , Carcinoma/diagnóstico por imagen , Carcinoma/cirugía , Carcinoma Neuroendocrino/diagnóstico por imagen , Carcinoma Neuroendocrino/cirugía , Carcinoma Papilar , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/diagnóstico por imagen , Periodo Posoperatorio , Estudios Prospectivos , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/cirugía , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/cirugía , Tirotropina/sangre , Ultrasonografía Doppler , Adulto JovenRESUMEN
OBJECTIVE: To evaluate the presence of persistent disease, including on post-therapy whole-body scan (RxWBS), in low-risk patients with papillary thyroid carcinoma (PTC) >1 cm who have low nonstimulated thyroglobulin (Tg) (measured with a sensitive assay), negative anti-Tg antibodies (TgAb) and neck ultrasound (US) showing no metastases after total thyroidectomy. PATIENTS: We studied 154 patients with PTC >1 cm classified as low risk, who had US without metastases, negative TgAb, nonstimulated Tg ≤ 0·25 ng/ml and TSH ≤ 2 mIU/l about 3 months after total thyroidectomy. RESULTS: Tg measured immediately before (131) I was ≤ 1 ng/ml in 89·5% of the patients and >1 ng/ml in 10·5%. None of the patients showed ectopic uptake on RxWBS. Uptake in the thyroid bed was observed in 146 (94·8%) patients and was ≤ 2% in all of them. In the control assessment 9-12 months after ablation, stimulated Tg (sTg) ≤ 1 ng/ml was achieved in 150 patients (97·4%). Only one patient had sTg >2 ng/ml (2·5 ng/ml) and none of the patients had apparent disease detected by imaging methods. During further short-term follow-up after control assessment (median of 24 months), none of the patients had tumour recurrence. CONCLUSIONS: The combination of nonstimulated Tg ≤0·25 ng/ml, negative TgAb and US without metastases after thyroidectomy rules out the presence of persistent disease (including on RxWBS) in low-risk patients with PTC >1 cm. This demonstration weakens the indication of ablation with (131) I in these cases.
Asunto(s)
Tiroglobulina/sangre , Adolescente , Adulto , Anciano , Carcinoma/sangre , Carcinoma Papilar , Femenino , Humanos , Radioisótopos de Yodo/uso terapéutico , Mediciones Luminiscentes , Masculino , Persona de Mediana Edad , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/sangre , Adulto JovenRESUMEN
We evaluated the negative predictive value (NPV) of thyroglobulin obtained 24 h after the second recombinant human TSH (rhTSH) ampoule (Tg-D3), before ablation with (131)I, for persistent/recurrent disease (PRD) in low/intermediate risk patients with papillary thyroid carcinoma. One hundred and one patients with Tg-D3 ≤ 1 ng/ml without anti-Tg antibodies (TgAb) were selected. Post-therapy whole-body scanning was negative for metastases in 98 (97 %) patients, and three patients showed discrete ectopic cervical uptake, but no corresponding disease was detected by neck ultrasound or computed tomography. One year after ablation, 98 (97 %) patients were free of the disease. Three patients had stimulated Tg >1 ng/ml, but no metastases were detected by the imaging methods. During follow-up (median 50 months), tumor recurrence was observed in only one patient. Thus, the NPV of Tg-D3 ≤ 1 ng/ml for PRD was 99 %. Among the 101 patients with Tg-D3 ≤ 1 ng/ml, Tg obtained 48 h after ablation (Tg-D5) continued to be ≤ 1 ng/ml in 56, and 45 had Tg-D5 >1 ng/ml. None of these 45 patients had PRD. In conclusion, Tg-D3 ≤ 1 ng/ml had a high NPV for PRD in patients without TgAb or known persistent disease and who are not at high risk. In these patients, Tg-D5 >1 ng/ml is more likely to reflect actinic damage to the remnant thyroid tissue rather than persistence of significant normal or tumor tissue.