Novel recombinant human thyroid-stimulating hormone in aiding postoperative assessment of patients with differentiated thyroid cancer-phase I/II study.

PURPOSE: Thyroid hormone withdrawal (THW) inevitably induced hypothyroidism in patients with differentiated thyroid cancer (DTC), and we aimed to evaluate the safety and efficacy of a novel recombinant human thyroid-stimulating hormone (rhTSH, ZGrhTSH) as an alternative of THW in China. METHODS: Totally, 64 DTC patients were enrolled with 24 in the dose-escalation cohort equally grouped into 0.9 mg × 1 day, 0.9 mg × 2 day, 1.8 mg × 1 day, and 1.8 mg × 2 day dosage, and 40 further enrolled into 0.9 mg × 2 day dose-expansion cohort. All patients underwent both ZGrhTSH phase and levothyroxine (L-T4) withdrawal phase for self-comparison in terms of TSH levels, the radioactive iodine (RAI) uptake, stimulated thyroglobulin level, and the quality of life (QoL). RESULTS: In ZGrhTSH phase, no major serious adverse events were observed, and mild symptoms of headache were observed in 6.3%, lethargy in 4.7%, and asthenia in 3.1% of the patients, and mostly resolved spontaneously within 2 days. Concordant RAI uptake was noticed in 89.1% (57/64) of the patients between ZGrhTSH and L-T4 withdrawal phases. The concordant thyroglobulin level with a cut-off of 1 µg/L was noticed in 84.7% (50/59) of the patients without the interference of anti-thyroglobulin antibody. The QoL was far better during ZGrhTSH phase than L-T4 withdrawal phase, with lower Billewicz (- 51.30 ± 4.70 vs. - 39.10 ± 16.61, P < 0.001) and POMS (91.70 ± 16.70 vs. 100.40 ± 22.11, P = 0.011) scores which indicate the lower the better. Serum TSH level rose from basal 0.11 ± 0.12 mU/L to a peak of 122.11 ± 42.44 mU/L 24 h after the last dose of ZGrhTSH. In L-T4 withdrawal phase, a median of 23 days after L-T4 withdrawal was needed, with the mean TSH level of 82.20 ± 31.37 mU/L. The half-life for ZGrhTSH clearance was about 20 h. CONCLUSION: The ZGrhTSH held the promise to be a safe and effective modality in facilitating RAI uptake and serum thyroglobulin stimulation, with better QoL of patients with DTC compared with L-T4 withdrawal.

Recombinant human thyroid-stimulating hormone versus thyroid hormone withdrawal preparation for radioiodine ablation in differentiated thyroid cancer in children, adolescents and young adults.

OBJECTIVE: Recombinant human TSH (rhTSH) is commonly used to prepare patients for postoperative radioiodine (I-131) ablation after surgery for differentiated thyroid cancer (DTC). In adults, rhTSH is associated with equivalent oncologic efficacy in comparison to thyroid hormone withdrawal (THW), but its use has not been well studied in children. We aimed to measure time to disease progression after rhTSH stimulation vs. THW in paediatric patients under the age of 21 with DTC following total thyroidectomy. DESIGN: Retrospective cohort study (March 2001-July 2018). PATIENTS: Sixteen children and adolescents (75% female, median age, 17.4 years) who received rhTSH were compared to 29 historical controls (72% female, median age, 18.5 years) prepared with THW, followed for a median of 2.4 years (range, 0.5-14). MEASUREMENTS: Stimulated serum TSH concentrations prior to I-131 ablation and time to disease progression, as determined by a component outcome variable encompassing both structural and biochemical disease persistence/recurrence. RESULTS: No differences were observed in tumour characteristics and I-131 dose (median 2.3 [1.8-2.90] mCi/kg rhTSH) between groups. Patients who received rhTSH achieved a similar median stimulated TSH level (163 [127-184] mU/L), compared to those who underwent THW (136 [94.5-197] mU/L; p = .20). Both groups exhibited similar time to progression (p = .13) and disease persistence/recurrence rates (rhTSH 31% vs. THW 59%, p = .14). CONCLUSION: In this cohort of children and adolescents with DTC, we observed similar time to disease progression among those who received rhTSH or underwent THW prior to postoperative I-131 ablation.

Early preablation rhTSH-stimulated thyroglobulin predicts outcome of differentiated thyroid cancer (DTC) patients.

AIM: Total thyroidectomy and risk-adapted 131-radioiodine therapy (RaIT) are the treatments of choice in differentiated thyroid cancer (DTC) patients. The response to treatments is assessed 6-12 months after RaIT. However, thyroglobulin (Tg) values obtained just before RaIT also provide reliable informations on patients'outcome. As available data were mostly obtained in hypothyroid status, we evaluated the predictive role of preablation-Tg in patients underwent RaIT after rhTSH stimulation. MATERIAL AND METHODS: We enrolled 299 low-to-intermediate risk DTC patients underwent rhTSH-stimulated RaIT (standard protocol). Serum Tg levels were measured before rhTSH administration (basal Tg), before RaIT (early-stimulated Tg), and 2 days after RaIT (late-stimulated Tg). The early response assessment was done 12 months after RaIT according to 2015 American Thyroid Association (2015 ATA) criteria. RESULTS: Most patients (277/299, 92.6%) had an excellent response (ER) to RaIT, while 15/299 (5.1%) and 7/299 (2.3%) patients showed biochemical incomplete/indeterminate response or persistent structural disease, respectively. At receiver operating characteristic analysis, the optimal cutoff to predict ER was set at 1.55 (AUC = 0.792), 2.6 (AUC = 0.931), and 4.9 (AUC = 0.874) ng/mL, for basal, early-, and late-stimulated Tg, respectively. The overall sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) for basal, early-, and late-stimulated Tg were 50%, 96.7%, 93.3%, 55%, and 96.1%; 90.9%, 84.5%, 84.9%, 31.7%, and 99.1%; and 90.9%, 71.8%, 73.2%, 20.4%, and 99%, respectively. In univariate and multivariate logistic regression analysis, early-stimulated Tg cutoff resulted as an independent prognostic marker for predicting ER regardless of gender, age, histotype, histological variant, tumor size, risk classification, and stage of disease. CONCLUSION: Early-stimulated Tg is a reliable diagnostic tool for predicting the response to primary treatment of DTC.

Recommendations for post-surgical thyroid ablation in differentiated thyroid cancer: a 2015 position statement of the Italian Society of Endocrinology.

UNLABELLED: Post-surgical ablation of thyroid remnant with radioactive iodine (RAI) in differentiated thyroid cancer (DTC) is aimed to destroy any thyroid remnant in the thyroid bed (remnant ablation) and any microscopic foci of cancer cells eventually present within the thyroid remnant (adjuvant therapy). The present text is an attempt to offer practice guidelines for the indication of thyroid ablation and the preparation of DTC patients considering the latest achievement in the field and the changing epidemiology of DTC observed in the last 10 years. METHODOLOGY: The executive committee of the Italian Society of Endocrinology appointed a task force of thyroid cancer expert including Nuclear Medicine Physicians and Endocrinologists to provide a consensus on the post-surgical ablation in thyroid cancer patients. The task force had no conflict of interest and had no commercial support. A number of specific topics were selected and the members selected relevant papers by searching in the Pubmed for articles published from 2000 to January 2015. Selected studies were categorized by level of evidence, and the recommendations were graded according to the level of evidence as high (A), moderate (B), or low (C).

Reappraisal of the indication for radioiodine thyroid ablation in differentiated thyroid cancer patients.

Radioactive iodine therapy is administered to patients with differentiated thyroid cancer (DTC) for eradication of thyroid remnant after total thyroidectomy or, in patients with metastatic disease, for curative or palliative treatment. In past years, thyroid remnant ablation was indicated in almost every patient with a diagnosis of DTC. Nowadays, careful revision of patients' outcome has introduced the concept of risk-based selection of patients candidate to thyroid remnant ablation. The present review aims to underline the indications for thyroid remnant ablation and to address methodologies to be employed.

Increased Pituitary Fluorine-18-Fluorodeoxyglucose Uptake in Patients with Differentiated Thyroid Cancer in Hypothyroidism versus under Recombinant Human Thyroid-Stimulating Hormone Stimulation.

BACKGROUND: 18F-FDG PET/CT is performed for the assessment of radioactive iodine non-avid disease in patients with DTC. In patients prepared by THW, increased pituitary uptake of 18F-FDG in the absence of pituitary disease may reflect the physiological activation of pituitary thyrotroph cells by hypothyroidism. This study aimed to compare pituitary 18F-FDG uptake in patients with DTC under THW vs. rhTSH stimulation. METHODS: A total of 57 patients with DTC undergoing 18F-FDG PET/CT (40 under THW and 17 under rhTSH stimulation) were retrospectively analyzed. Pituitary metabolism was expressed as maximum standardized uptake value (SUVmax) and as SUVratio using the right cerebellum as reference. RESULTS: Pituitary hypermetabolism (SUVmax ≥ 4.1) was present in more patients in the THW group compared to the rhTSH group (62.5% vs. 23.5%; p = 0.01). Pituitary metabolism was significantly higher in the THW group compared to the rhTSH group, as assessed by either SUVmax (mean ± SD: 4.61 ± 1.22, 95%CI: 4.22-5.00 vs. 3.34 ± 0.86, 95%CI: 2.9-3.8; p < 0.001) or SUVratio (0.52 ± 0.11, 95%CI: 0.49-0.56 vs. 0.42 ± 0.07, 95%CI: 0.38-0.46; p < 0.001). Serum TSH levels correlated positively with SUVmax (r = 0.41, p < 0.01) and SUVratio (r = 0.44, p < 0.01) in the THW group only. CONCLUSIONS: The present findings support the hypothesis that pituitary hypermetabolism on 18F-FDG PET/CT in patients with DTC undergoing THW is a common physiological response to hypothyroidism. Awareness of this physiological hypermetabolism is important to avoid potential pitfalls in image interpretation.

Poly (lactic-co-glycolic acid)-encapsulated iodine-131 nanoparticles fabricated with rhTSH induce apoptosis and immobilization of thyroid cancer cells.

Background: Aggressive thyroid carcinoma (ATC) usually loses radioiodine avidity to iodine-131 (131I) due to the downregulation of sodium/iodide symporter (NIS). The expression of thyroid stimulating hormone receptor (TSHR) is more persistent than NIS and the administration of recombinant human thyroid stimulating hormone (rhTSH) promotes de novo NIS synthesis. Hence, exploring methods integrating 131I with rhTSH might be a feasible therapeutic strategy for selective delivery of 131I into thyroid cancer to fortify the effect of radioiodine ablation. Methods: The 131I, poly (lactic-co-glycolic acid) (PLGA) and rhTSH were used to synthesize of the 131I-PLGA-rhTSH nanoparticles. The characteristics of the 131I-PLGA-rhTSH nanoparticles was determined using a light microscopy, scanning electron microscopy (SEM), autoradiography and immunofluorescence (IF) staining. The diameter of the 131I-PLGA-rhTSH nanoparticles was measured with a Mastersizer 3000, and the encapsulation efficiency (EF) of 131I in 131I-PLGA-rhTSH nanoparticles and the radioactivity of a single nanoparticle were determined. Then, the mouse tumor xenograft model was established, and the biodistribution and effect of 131I-PLGA-rhTSH nanoparticles on apoptosis of thyroid cance cells were investigated in vivo. Thereafter, the role of 131I-PLGA-rhTSH nanoparticles in cell viability using cell counting kit-8 and lactate dehydrogenase (LDH) release assays. Subsequently, the underlying mechanism of 131I-PLGA-rhTSH nanoparticles in reducing cell viability was assessed using immunostaining, boyden invasion assays and phalloidin staining. Results: Our results showed that the method of developing nanoparticles-encapsulated 131I using poly (lactic-co-glycolic acid) (PLGA) and modified with rhTSH (131I-PLGA-rhTSH), was a feasible avenue for the integration of 131I and rhTSH. Meanwhile, the encapsulation efficiency (EF) of 131I-PLGA-rhTSH nanoparticles was approximately 60%, and the radioactivity of a single nanoparticle was about 1.1×10-2 Bq. Meanwhile, the 131I-PLGA-rhTSH nanoparticles were selectively delivered into, gradually enriched and slowly downregulated in xenograft tumor after the administration of 131I-PLGA-rhTSH nanoparticles through tail vein in mouse tumor xenograft model. Thereafter, the tumor weight was significantly reduced after the administration of 131I-PLGA-rhTSH nanoparticles. Subsequently, the application of 131I-PLGA-rhTSH nanoparticles facilitated apoptosis and attenuated immobilization via inhibiting F-actin assembling of FTC-133 cells. Conclusion: The present study develops a suitable approach integrating 131I and rhTSH, and this strategy is a feasible regimen enhancing the effect of radioiodine ablation for the treatment of thyroid cancer.

Initial Evaluation of Therapy Response after Adjuvant Radioiodine Therapy in Patients with Early-Stage Papillary Thyroid Cancer-Does Time Matter?

BACKGROUND: The aim was to assess ablation success after initial radioiodine (RAI) therapy in early-stage PTC patients and compare outcomes of first diagnostic control after 6 and 9 months (6m/9m-DC) to examine whether time could possibly avoid unnecessary overtreatment. METHODS: There were 353 patients who were matched regarding age, sex, and tumor stage and divided in two groups depending on time of first DC (6m- and 9m-DC). Therapy response was defined as thyroglobulin level <0.5 ng/mL, no pathological uptake in the diagnostic I-131 whole-body scintigraphy (WBS), and no further RAI therapy courses. The 6m-DC group was further divided into endogenously and exogenously stimulated TSH before RAI therapy and compared regarding outcome. RESULTS: No significant differences were found between 6m-DC vs. 9m-DC regarding I-131 uptake in WBS (p = n.s.), Tg levels (p = n.s.), re-therapy rates (p = n.s.), and responder rates (p = n.s.). Significantly less relevant pathological I-131 uptake was found in WBS (p = 0.006) in endogenously compared to exogenously stimulated 6m-DC patients, resulting in lower re-therapy (p = 0.028) and higher responder rates (p = 0.001). CONCLUSION: DC at 6 months after RAI therapy and stimulation with recombinant human thyroid-stimulating hormone (rhTSH) represent the most balanced solution. Particularly regarding quality of life and mental relief of patients, early DC with rhTSH represents sufficient and convenient assessment of ablation success.

Analysis of Short-Term and Stable DNA Damage in Patients with Differentiated Thyroid Cancer Treated with 131I in Hypothyroidism or with Recombinant Human Thyroid-Stimulating Hormone for Remnant Ablation.

It is well known that ionizing radiation can induce genetic damage and that oxidative stress is a major factor inducing it. Our aim was to investigate whether thyroid remnant ablation with low activities of 131I (1,850 MBq) is associated with DNA damage by evaluating the CometAssay, micronuclei, and chromosome aberrations with multicolor fluorescent in situ hybridization. Methods: We studied 62 patients prepared with recombinant human thyroid-stimulating hormone (rhTSH) or by thyroid hormone withdrawal. In both groups, we analyzed stable and unstable genetic alterations before 131I therapy and 1 wk and 3 mo after 131I administration. We also correlated the genetic damage with several variables, including the degree of radiation-induced oxidative stress, genetic polymorphisms of enzymes involved in DNA repair, and antioxidative stress. Results: We found a comparable amount of DNA breaks evaluated by CometAssay and micronuclei testing in both groups of patients at different time points, but there was a significant increase in stable chromosome aberrations evaluated by multicolor fluorescent in situ hybridization (breaks and translocations) in patients prepared with thyroid hormone withdrawal. Overall, high chromosome damage was associated with higher retained body radioactivity and unfavorable gene polymorphism. A high level of free oxygen radicals and a low level of antioxidants were found in all patients at any time point. In particular, patients prepared with thyroid hormone withdrawal, at 3 mo, had significantly higher levels of free oxygen radicals than those prepared with rhTSH. Conclusion: An increase in stable chromosome aberrations with respect to baseline is detectable after administration of low doses of 131I in patients prepared with thyroid hormone withdrawal but not in patients prepared with rhTSH. The clinical significance of these chromosomal alterations remains to be determined.

Benign thyroid nodules respond to a single administration of 0.3mg recombinant human thyrotropin with highly variable volume increase.

Introduction: The nature of thyroid nodules is heterogenous. Most of them are benign and, in the absence of pressure symptoms of adjunct structures, no treatment is needed. Our objective was to investigate the acute effects of a low dose of recombinant human TSH (rhTSH) on the volume of benign thyroid nodules. Methods: we studied 27 nodules (14 isoechoic and 13 hypoechoic) in 15 (11 women and 4 men; mean age: 51.0 ± 15.9 years) consecutive patients with one to three well-separated asymptomatic benign thyroid nodules. All subjects were euthyroid, with negative thyroid antibodies, and none received levothyroxine. The total thyroid volume and thyroid nodule volume were sonographically determined by two independent examiners (P.B. and M.M.) before, 48 hours and 6 months post intramuscular (IM) administration of 0.3mg rhTSH, and the mean values of the two examiners' measurements were used; thyroid function tests were obtained at the same time points. Results: The mean volume of isoechoic nodules increased by 57.3%, of hypoechoic nodules by 46.6% and of the surrounding thyroid parenchyma by 70.4% 48 hours post-rhTSH; mean volumes had returned to baseline levels 6 months later. A large variance in the volume change responses was observed. The relative change in nodule volume (defined as the percent change in nodule volume divided by the percent change in the surrounding parenchyma) from baseline to 48 hours was significantly higher in isoechoic versus hypoechoic nodules (p<0.05). Conclusions: A single dose of 0.3 mg rhTSH transiently increased the volume of benign thyroid nodules. The increase was more pronounced in isoechoic nodules and had a great variability. Our findings could be useful in the management of benign thyroid nodules, by helping in understanding which nodules would be more responsive to TSH suppression therapy.

Familial longevity is associated with lower baseline bone turnover but not differences in bone turnover in response to rhTSH.

CONTEXT: Offspring from long-lived families have a different thyroid status than controls, characterised by higher circulating levels of thyroid stimulating hormone (TSH) and similar levels of thyroid hormone. Expression of the TSH receptor has previously been observed on various extrathyroidal tissues, including bone. However, potential physiological consequences of differences in circulating TSH as observed in familial longevity on bone tissue remain unclear. OBJECTIVE: Based on the hypothesis that TSH may inhibit bone resorption, we explored whether offspring of long-lived families have lower bone turnover than controls at baseline as well as following a challenge with recombinant human TSH (rhTSH). METHODS: Bone turnover markers CTX and P1NP were measured in fasted morning samples from 14 offspring and 12 controls at baseline and at 24 hour intervals following 0.1 mg rhTSH i.m. administration for four consecutive days. RESULTS: At baseline, mean (SEM) CTX was 0.32 (0.03) ng/ml in offspring and 0.50 (0.04) ng/ml in controls, p < 0.01, whereas mean (SEM) P1NP was 39.6 (3.2) ng/ml in offspring and 61.8 (6.6) ng/ml in controls, p < 0.01. Following rhTSH administration, both CTX and P1NP levels transiently increased over time and normalized towards baseline after 72 h (general linear modelling: CTX time p = 0.01, P1NP time p < 0.01); the response was similar between offspring and controls. CONCLUSIONS: Bone turnover markers were lower at baseline in offspring from long-lived families than in controls but increased similarly following an rhTSH challenge.

Determining the frequency of thyroid parameter measurements following rhTSH administration in a healthy, older population.

Serial thyroid hormone measurement in blood following recombinant human thyroid stimulating hormone (rhTSH) administration has not been studied extensively in healthy, older populations. Current methods involve measurement of thyroid hormones mostly at 4 to 24 hours following rhTSH administration. We tailored existing protocols to measure thyroid hormones at high frequencies following 0.1mg rhTSH intramuscular (i.m.) administration to identify optimal measurement points in our healthy, older population. We designed a method with frequent blood sampling in the first 8 hours, followed by blood sampling at 24, 48 and 72 hours after rhTSH administration to measure TSH, thyroxine (T4), free T4 (fT4), triiodothyronine (T3), free T3 (fT3) and thyroglobulin (Tg). In total, we performed a series of 17 blood withdrawals in four consecutive days. Following 0.1mg rhTSH (i.m.) administration, mean thyroid parameters showed great inter-individual variation and variation over time. Mean TSH concentration showed the greatest variation in the first 8 hours following rhTSH administration. Mean T4, fT4, T3 and fT3 started showing variation from 2 hours after rhTSH administration, and were less variable than mean TSH concentration. Mean Tg was only variable at later time points, namely 24, 48 and 72 hours after rhTSH administration. In this novel method with high frequency blood sampling following 0.1mg rhTSH (i.m.) administration, we identify optimal time points for measuring thyroid gland output in a healthy, older population. Our methods and findings may be informative for further thyroid but also other hormonal axis studies.•Thyroid metabolism•Blood sampling frequency•Geriatrics and longevity.

In Vivo Imaging of Thyroid Cancer with 99mTc-TR1401 and 99mTc-TR1402: A Comparison Study in Dogs.

Differentiated thyroid cancer (DTC) cells may lose NIS expression and iodine uptake, but usually express TSH receptors (TSHR). Therefore, the aim of our study was to compare two radiolabeled superagonist TSH analogues for DTC imaging. These analogues (namely TR1401 and TR1402) have a higher TSHR binding affinity than recombinant human TSH (Thyrogen®). Radiolabeling was performed with technetium-99m using an indirect method via HYNIC conjugation and was followed by in vitro quality controls and binding assay on TSHR-positive cell lines (ML-1). An in vitro binding assay was also performed and compared with radiolabeled human recombinant TSH. In vivo imaging was performed in four dogs with spontaneous follicular thyroid carcinoma with solid poorly differentiated areas with 99mTc-TR1401 SPECT/CT, 99mTc-TR1402 SPECT/CT, and [18F]FDG PET/CT on different days within 2 weeks. TR1401 and TR1402 were labeled with high specific activity (8.3 ± 1.2 MBq/µg) and retention of their biological activity and structural integrity. Both agonists were able to efficiently bind TSHR receptors expressed by cell lines with dissociation constants (Kd) of 2.7 nM for 99mTc-TR1401 and 0.5 nM for 99mTc-TR1402 compared with 99mTc-Thyrogen (Kd = 8.4 nM). In tumor-targeting experiments, a focal uptake was observed in dogs with spontaneous intraglandular thyroid carcinoma, in which TSHR expression was confirmed by immunohistochemistry. 99mTc-TR1402 provided higher T/B than 99mTc-TR1401 and [18F]FDG (12.9 ± 1.3, 10.2 ± 0.7, and 3.8 ± 0.6, respectively; all p < 0.001). Given these results, 99mTc-TR1402 appears to be a useful tool for in vivo imaging of thyroid cancer.

Outcomes of Thyrotropin Alfa Versus Levothyroxine Withdrawal-Aided Radioiodine Therapy for Distant Metastasis of Papillary Thyroid Cancer.

Background: Thyrotropin alfa (rhTSH) is not currently approved by the Food and Drug Administration or European Medicines Agency for the preparation of radioactive iodine therapy (RAIT) in patients with distant metastatic papillary thyroid cancer (PTC). There are only a few studies comparing rhTSH with levothyroxine withdrawal (LTW) in this context. Our main aim was to compare the two methods of RAIT preparation in terms of avidity and structural/biochemical response in distant metastatic PTC. We also intended to evaluate whether the two methods of RAIT preparation represented independent prognostic factors for progression-free survival (PFS) and disease-specific survival (DSS) in this subset of patients. Methods: We performed a retrospective analysis of all patients with PTC treated with RAIT for distant metastatic disease between 2006 and 2018. We included 95 PTC patients-27 (28.4%) had LTW and 68 (71.6%) had rhTSH for RAIT. Results: The two groups presented similar clinicopathological characteristics, except for median age at PTC diagnosis, which was higher in the rhTSH group (p = 0.001), but the median age at first RAIT for distant metastatic disease was not different between the two methods of preparation, 63 years old (interquartile range [IQR] 23) in the LTW group versus 70 (IQR 26.75), p = 0.06. Avidity was similar between the two groups (p = 0.973). Median estimate PFS (p = 0.076) and DSS (p = 0.084) were also similar between LTW and rhTSH. Regarding RAIT-related side effects, only 1 (3.7%) patient and 5 (7.4%) patients in the LTW and rhTSH groups, respectively, reported sialadenitis (p = 0.670). Conclusions: There were no differences between the two methods of RAIT preparation regarding avidity and clinical response. rhTSH may be used as an alternative method of preparation for RAIT in patients with known distant lesions, as it presents similar clinical outcomes to LTW and a good safety profile.

Only peak thyroglobulin concentration on day 1 and 3 of rhTSH-aided RAI adjuvant treatment has prognostic implications in differentiated thyroid cancer.

OBJECTIVE: In patients with differentiated thyroid carcinoma (DTC), serum thyroglobulin levels measured at the time of remnant ablation after thyroid hormone withdrawal were shown to have prognostic value for disease-free status. We sought to evaluate serial thyroglobulin measurements at the time of recombinant human thyroid-stimulating hormone (rhTSH)-aided iodine 131 (131I) adjuvant treatment as prognostic markers of DTC. METHODS: Six hundred-fifty patients with DTC given total/near-total thyroidectomy and adjuvant radioiodine post-rhTSH stimulation were evaluated. Thyroglobulin was measured on day 1 (Tg1; at the time of the first rhTSH injection), day 3 (Tg3; 1 day after the second, final rhTSH injection), and day 6 (Tg6; 3 days post-radioiodine administration). Treatment failure was defined as histopathologically confirmed locoregional recurrence, or radiologically-evident distant metastases (signs of disease on computer tomography (CT) or magnetic resonance imaging (MRI), or abnormal foci of radioiodine or [18F] fluorodeoxyglucose ([18F]FDG) uptake. RESULTS: In univariate analysis, Tg1 (p < 0.001) and Tg3 (p < 0.001), but not Tg6, were significantly associated with structural recurrence. In multivariate analysis of the overall cohort, only Tg3 was independently associated with structural recurrence. In multivariate analysis of the subgroup (n = 561) with anti-Tg antibodies titers below the institutional cut-off, 115 IU/mL, Tg1 was an independent prognostic marker. Tg1 and Tg3 cutoffs to best predict structural recurrence were established at 0.7 ng/mL and 1.4 ng/mL, respectively. CONCLUSIONS: Tg1 and Tg3, measurements made after rhTSH stimulation but before radioiodine treatment, independently predict a low risk of treatment failure in patients with DTC. Levels measured post-radioiodine application (e.g., Tg6) are highly variable, lack prognostic value, and hence can be omitted.

Acute airway compromise after recombinant human TSH administration: A case report and review of the literature.

Radioiodine ablation is a commonly utilized treatment for differentiated thyroid carcinoma. Uptake of radioiodine can be enhanced by pretreatment with thyroid hormone withdrawal or administration of recombinant human thyroid-stimulating hormone (rhTSH). rhTSH is generally well-tolerated with minimal adverse effects. However, in patients with extensive tumor burden in confined anatomic spaces, rapid enlargement of normal or neoplastic thyroid tissue secondary to rhTSH administration can result in significant compressive effects. In this report, we describe a case of rapid airway deterioration requiring intubation in a patient with involvement of the thyroid cartilage by papillary thyroid carcinoma. Laryngoscope, 122:0000-0000, 2019 Laryngoscope, 130:2725-2727, 2020.

Effect of rhTSH on Lipids.

BACKGROUND: Subclinical hypothyroidism is associated with increased blood lipid levels. However, the exact role of thyrotropin (TSH) alone is not clear. In order to clarify this point, we analysed the acute effect of recombinant human TSH (rhTSH) administration on lipid levels. METHODS: Sera of 27 premenopausal women with well-differentiated thyroid cancer were analysed. Patients that underwent a total thyroidectomy, ablation with 131I (Iodine 131) and rhTSH administration as a part of routine follow-up American Thyroid Association guidelines were included. The protocol consists of 2 intramuscular injections of 0.9 mg of rhTSH, performed on day 1 day and day 2, with blood collection on day 1 (before rhTSH administration), and day 5. TSH, free thyroxine, total cholesterol, low-density lipoprotein cholesterol (LDLc), high density lipoprotein cholesterol (HDLc), and triglycerides were assessed in all the samples, before and four days after the first administration of rhTSH. RESULTS: Total cholesterol and triglycerides significantly increased after stimulation of rhTSH (respectively, 192 ± 33 vs. 207 ± 26, p = 0.036 and 72 ± 23 vs. 85 ± 23, p = 0.016). LDLc and HDLc showed comparable concentrations before and after the test (respectively, 115 ± 27 vs. 126 ± 22, p = 0.066, and 62 ± 15 vs. 64 ± 15, p = 0.339), while non-HDLc increased after stimulation (130 ± 30 vs. 143 ± 25, p = 0.045). CONCLUSION: TSH has a direct effect on total cholesterol, triglycerides, and nonHDLc. Explanation of these phenomena will require additional studies.

Evaluation of SNA001, a Novel Recombinant Human Thyroid Stimulating Hormone Injection, in Patients With Differentiated Thyroid Carcinoma.

SNA001 is a novel recombinant human thyroid stimulating hormone (rhTSH). rhTSH has long been approved in several countries to facilitate monitoring and ablation of thyroid carcinoma without hypothyroidism caused by thyroid hormone withdrawal (THW). To assess the safety, tolerance, pharmacokinetic and pharmacodynamic properties of SNA001, the two-period (SNA001 period and THW period), dose-ascending study in well-differentiated thyroid cancer (DTC) patients was designed. Three doses (0.45 mg, 0.9 mg, and 1.35 mg) of SNA001 were intramuscularly injected, twice in the SNA001 period to stimulate iodine-131 uptake and thyroglobulin (Tg) release. 24 h after the last dose of SNA001, iodine-131 (111-185 MBq) was administrated, followed by whole-body scan (WBS) 48 h later. THW period began just after SNA001 washout and lasted for about 3-6 weeks. When TSH level was above 30 mU/L, iodine-131 (111-185 MBq) was administrated, followed by a WBS and Tg detection 48 h later. Twenty-four DTC patients after thyroidectomy were enrolled; mean peak concentrations of SNA001 in 0.45, 0.9, and 1.35 mg groups were 18.5, 26.7, and 37.0 ng/ml (about 244.7, 354.2, and 489.6 mU/L) respectively, within 28-32 h after first dose of SNA001. SNA001 was metabolized in a dose-dependent manner. The results of WBS and Tg release in the SNA001 period were compared with those in the THW period. Compared to Tg level in baseline, the Tg levels in SNA001 and THW periods were increased, with 78% of subjects showing higher Tg levels in the THW period. 100% of the patients had concordant qualitative results of the scans within two periods in three groups. Symptoms of hypothyroidism were relieved in the SNA001 period compared with THW period, though there was no significant difference in most of the scale scores. There were no serious adverse events related to SNA001; the most common adverse events were gastrointestinal symptoms of mild and transient nature. Thus, SNA001 promises to be a safe and effective method to stimulate iodine-131 uptake and Tg secretion during monitoring and ablation for DTC without the disadvantages of incidental hypothyroidism.

Utility of recombinant human TSH stimulation test in the follow-up of patients with differentiated thyroid cancer depending on basal thyroglobulin results.

Background: Thyroglobulin (Tg) is fundamental for differentiated thyroid cancer (DTC) monitoring. Tg detection can be enhanced using recombinant human thyroid-stimulating hormone (TSH) (rhTSH). This study is aimed to evaluate the use of the rhTSH stimulation test when using a high-sensitivity Tg assay. Methods: We retrospectively studied 181 rhTSH tests from 114 patients with DTC and negative for antithyroglobulin antibodies (anti-TgAb). Image studies were performed in all cases. Serum Tg and anti-TgAb were measured using specific immunoassays. Results: rhTSH stimulation in patients with basal serum Tg (b-Tg) concentrations lower than 0.2 ng/mL always resulted in rhTSH-stimulated serum Tg (s-Tg) concentrations lower than 1.0 ng/mL and negative structural disease. In patients with b-Tg concentration between 0.2 and 1.0 ng/mL, s-Tg detected one patient (1/30) who showed biochemical incomplete response. Patients with negative images had lower s-Tg than those with nonspecific or abnormal findings (p<0.05). Receiver operating characteristic curve analysis of the s-Tg to detect altered images showed an area under the curve of 0.763 (p<0.05). With an s-Tg cutoff of 0.85 ng/mL, the sensitivity was 100%, decreasing to 96.15% with an s-Tg cutoff of 2 ng/mL. Conclusions: Patients with DTC with b-Tg concentrations equal or higher than 0.2 ng/mL can benefit from the rhTSH stimulation test.

Response to Therapy Assessment in Intermediate-Risk Thyroid Cancer Patients: Is Thyroglobulin Stimulation Required?

Introduction: The 2015 American Thyroid Association (ATA) guidelines recommend response to therapy (RTT) assessment 1-2 years after initial treatment in differentiated thyroid cancer (DTC) patients to guide thyrotropin (TSH) goals and long-term follow-up. We hypothesized that data collected during the first 2 years of follow-up may be sufficient to determine RTT without thyroglobulin (Tg) stimulation. Materials and Methods: Patients treated with total thyroidectomy and radioiodine for intermediate-risk DTC, followed for >2 years, and had sufficient follow-up data were included. Data on Tg, ultrasound, scans, and long-term outcomes were collected. Results: One-hundred twenty patients met inclusion criteria, with 68% women and mean age 55 ± 15 years. Intermediate risk was due to lymph-node involvement (72%), extrathyroidal extension (51%), vascular invasion (12%), and high-risk histology (9%). At the end of follow-up of 7 ± 4 years, 26% had persistent disease (14% biochemical, 12% structural). According to the ATA RTT system (using stimulated-Tg), 56% had excellent RTT, of whom only 2% had disease at the end of follow-up. In the "nonstimulated" system (which includes basal Tg, post-131I therapy whole-body scan (TxWBS) for assessment of residual lymph-node metastases after surgery, and structural imaging studies), 57% had excellent response, of whom none had disease at the end of follow-up. Only eight patients (7%) were classified differently due to recombinant human thyrotropin stimulation (as either excellent or indeterminate response), with no difference in predictive value, with a receiver-operator characteristic area under the curve of 0.903 with Tg-stimulation and of 0.918 without. Conclusions: In patients with no evidence of disease during the first 2 years of follow-up, the addition of stimulated-Tg adds little prognostic information. We suggest the use of excellent RTT based on basal Tg together with TxWBS and structural imaging studies.