rhTSH-stimulated Tg Level Research Articles

Can the basal serum thyroglobulin level be used to predict the recombinant human TSH-stimulated thyroglobulin level in differentiated patients with thyroid cancer?

This study investigated the correlation between basal thyroglobulin (Tg) and recombinant human thyroid-stimulating hormone (rhTSH)-stimulated Tg in differentiated patients with thyroid cancer, and sought to determine whether the basal Tg level predicts the rhTSH-stimulated Tg level.We retrospectively enrolled 177 patients with papillary thyroid cancer (mean age = 44 years; 50 males, 127 females) who received rhTSH before radioiodine therapy (RIT). Serum Tg levels were measured 7 days before the 1st rhTSH injection (basal Tg) and on the days of RIT (rhTSH-stimulated Tg). Patients were divided into 3 groups according to rhTSH-stimulated Tg cut-off levels of 2, 5, and 10 ng/mL. The correlation between basal Tg and rhTSH-stimulated Tg levels was assessed, and whether basal Tg was useful in predicting the rhTSH-stimulated Tg level was determined.A significant positive correlation was observed between basal and rhTSH-stimulated Tg levels (|rho| = 0.48, P < .0001). The basal Tg level had significant diagnostic ability in predicting an rhTSH-stimulated Tg level of 2 ng/mL or higher, and the optimal basal Tg level for this prediction was 0.3 ng/mL (AUC = 0.77, P < .0001). A basal Tg level of 0.5 ng/mL was optimal for predicting rhTSH-stimulated Tg levels of 5 ng/mL or higher (AUC = 0.81, P < .0001), and of 10 ng/mL or higher (AUC = 0.82, P = .0171).The basal Tg level was significantly correlated with the rhTSH-stimulated Tg level. If the basal Tg level is >0.3 or 0.5 ng/mL, then the rhTSH-stimulated Tg level can be expected to be sufficiently high to necessitate clinical examination.

Recombinant human thyrotropin-stimulated thyroglobulin level at the time of radioactive iodine ablation is an independent prognostic marker of differentiated thyroid carcinoma in the setting of prophylactic central neck dissection.

We investigated the value of the stimulated thyroglobulin (Tg) level at the time of recombinant human thyrotropin (rhTSH)-aided remnant ablation for predicting disease status 1year later in patients with DTC who underwent total thyroidectomy with central neck dissection (CND). This was a prospective observational study of 253 consecutive patients with DTC who underwent rhTSH-aided RAI ablation after total thyroidectomy and prophylactic CND. Patients with evidence of initial distant metastasis or positive Tg antibodies were excluded. We compared rhTSH-stimulated Tg level at RAI ablation according to the disease status at 1year and evaluated optimal cut-off value of rhTSH-stimulated Tg. Binary logistic regression analysis was performed to investigate the independent predictive factors for disease status 1year after ablation. Among study participants, 228 (90·1%) were considered disease free at 1year after remnant ablation. Patients with persistent or recurrent disease were more likely to be aged ≥45years, and to have N1b stage, TNM stage III or IV, and higher rhTSH-stimulated Tg level at RAI ablation. The optimal cut-off of rhTSH-stimulated Tg for predicting persistent or recurrent disease was 1·79ng/ml, with a negative predictive value of 99·5%. A serum rhTSH-stimulated Tg level ≥1·79 at the time of ablation was independently associated with persistent or recurrent disease 1year later. N1b stage tended to be associated with persistent or recurrent disease. A low stimulated serum Tg level at rhTSH-aided RAI ablation may be a favourable prognostic marker in the setting of prophylactic CND.

Ability of the rhTSH stimulation test to predict relapse in patients with differentiated thyroid carcinoma, after long-term follow-up.

The analysis of serum thyroglobulin (Tg) following thyroid-stimulating hormone (TSH) stimulation (sTg) has been recommended in the follow-up of differentiated thyroid carcinoma (DTC) patients, however, its routine use remains controversial. The aim of the current study was to evaluate the accuracy of sTg testing following recombinant human (rh) TSH stimulation in DTC patients, with a follow-up of 12.4 years. Retrospective studies were conducted of 125 DTC patients, who underwent rhTSH stimulation testing between 1999 and 2002. The exclusion criteria were: Patients with anti-Tg antibodies, Tg levels >1 ng/ml under TSH suppression and the absence of radioactive iodine (RAI) ablation therapy following surgery. In total, 49 patients were included in the study and all had been previously treated with total or near total thyroidectomy (with or without central neck dissection) and RAI, postoperatively. The Tg functional sensitivity was 1.0 ng/ml. The follow-up for patients was performed annually. During the median follow-up of 12.4 years after the rhTSH stimulation test, nine patients exhibited recurrence (18.4%). Of the nine patients, six exhibited sTg levels >2 ng/ml (positive result) and three exhibited levels <2 ng/ml (negative result). Relapse occurred at a mean of 5.9 years following the rhTSH stimulation test. The positive predictive value and negative predictive value (NPV) of positive sTg were 50 and 91.9%, respectively, with a sensitivity of 66.6% and a specificity of 85.0%. The rhTSH-stimulated Tg levels have a high NPV, allowing the identification of the patients who are free of the tumour. These results are consistent with the previously published data; however, to the best of our knowledge, this is the study with the longest follow-up duration after rhTSH stimulation.

Comparing the effectiveness of stimulation using rhTSH and thyroid hormone withdrawal in the treatment of thyroid cancer

Comparing the effectiveness of stimulation using rhTSH and thyroid hormone withdrawal in the treatment of thyroid cancer

Does an undetectable rhTSH-stimulated Tg level 12months after initial treatment of thyroid cancer indicate remission?

Does an undetectable rhTSH-stimulated Tg level 12months after initial treatment of thyroid cancer indicate remission?

Does an undetectable rhTSH-stimulated Tg level 12months after initial treatment of thyroid cancer indicate remission?

Does an undetectable rhTSH-stimulated Tg level 12months after initial treatment of thyroid cancer indicate remission?

Is Diagnostic Iodine-131 Scanning with Recombinant Human TSH Useful in the Follow-Up of Differentiated Thyroid Cancer after Thyroid Ablation?

Measuring serum Tg and performing a diagnostic whole body scan (DxWBS) has become the standard for follow-up of patients with differentiated thyroid carcinoma. The primary aim of this study was to determine whether recombinant human TSH (rhTSH)-stimulated Tg alone is sufficiently sensitive to identify residual cancer in patients with no clinical evidence of disease and undetectable or very low serum Tg levels during thyroid hormone (TH) therapy. A secondary aim was to investigate the frequency of tumor in such patients. One hundred and seven consecutive patients, aged 10.9–85.3 yr (median, 36.3), at the time of initial surgery who had Tg levels on TH therapy that were undetectable (95% ≤0.5 ng/ml) or low (4% 0.6 ng/ml, 1% 1.0 ng/ml) and who underwent rhTSH-stimulated testing 10 months to 35 yr (median, 3.5 yr) after initial thyroidectomy and 131I ablation were retrospectively studied. Many (50%) were at high risk of tumor recurrence, and 5 had distant metastases during the course of their disease. In response to rhTSH, Tg ranged from 0.5 or less to 17.9 ng/ml, remaining at 0.5 ng/ml or less in 68 (64%) patients and increasing to levels between 0.6 and 2 ng/ml in 19 (18%) others and to levels higher than 2 ng/ml in 20 (19%) patients. Eleven patients (10%), all of whom had rhTSH-stimulated serum Tg levels above 2 ng/ml, were found to have persistent tumor in lung (4 patients), lymph nodes (5 patients, 3 with cervical central compartment, 1 bilateral cervical, and 1 with mediastinal nodes) identified by fine needle cytology, surgical pathology, posttherapy whole body scans, or computed tomography and, in two patients, with high serum Tg values alone (4.6 and 7.0 ng/ml after rhTSH and, respectively, 28.5 and 70.6 ng/ml after TH withdrawal), although in neither could the tumor site be identified. Thirteen patients (12%) were treated with surgery or 131I, and in some cases both, as a result of the rhTSH studies; 10 had tumor, 1 had residual uptake in the thyroid bed visible on rhTSH-stimulated diagnostic whole body scan (DxWBS), and 2 had high serum Tg levels, presumably originating from a tumor site that could not be identified. A patient’s tumor status, even in retrospect, usually was not predictable on the basis of Tg during TH therapy or tumor node metastasis status: among patients found to have tumor after rhTSH, serum Tg during TH therapy was 0.5 ng/ml or less in 55% and 0.6 ng/ml in 36%, and tumor node metastasis status was T2N1 or less in 82%. In no case did the rhTSH-stimulated DxWBS show the site of persistent tumor. There were correlations between visible thyroid bed uptake on DxWBS and quantitated 131I uptake (r2 = 0.11; P = 0.001), between DxWBS and rhTSH-stimulated Tg (r2 = 0.54; P = 0.001), and between rhTSH-stimulated Tg and 131I uptake (r2 = 0.66; P = 0.0001). There was no statistically significant difference (P = 0.4) in bed 131I uptake in patients with rhTSH-stimulated serum Tg levels of 0.5 ng/ml or less compared with that in subjects with higher rhTSH-Tg levels. An rhTSH-stimulated Tg level greater than 2 ng/ml had a sensitivity of 100%, a negative predictive value of 100%, and a false positive rate of 9%. The rhTSH Tg had a substantially better performance than the other studies; the false negative rates were 64% for Tg higher than 0.5 ng/ml on TH therapy, 73% for rhTSH-stimulated DxWBS showing uptake, and zero for an rhTSH-stimulated Tg more than 2 ng/ml. In conclusion, of 107 patients who were clinically free of disease, 10% had persistent tumor (4 with pulmonary metastases and 5 with regional disease) that was only identified with an rhTSH-stimulated serum Tg level greater than 2 ng/ml. This study shows that tumor amenable to early therapy may be found when rhTSH-stimulated serum Tg rises above 2 ng/ml without performing a DxWBS, which merely provides data concerning the completeness of thyroid ablation, but not persistent tumor. An elevated rhTSH-stimulated Tg greater than 2 ng/ml warrants further study.