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.

Sialadenitis following low dose I-131 diagnostic thyroid scan with Thyrogen® (recombinant human thyroid stimulating hormone--thyrotropin alfa).

Salivary dysfunction and sialadenitis are well known complications of radioiodine treatment for thyroid cancer. The parotid gland is more frequently affected and the salivary gland injury is dose related. The symptoms may develop shortly after therapeutic Iodine 131(I-131) administration or months later and progress with time. The development of unilateral parotiditis following a low dose, diagnostic I-131 scan performed following Thyrogen stimulation in a patient without prior history of sialadenitis is rare in our experience, and has not been reported in the medical literature.

Unexpected symptoms after rhTSH administration due to occult thyroid carcinoma metastasis.

¹8F-fluorodeoxyglucose positron emission tomography (¹8FDG-PET) scintigraphy is a useful imaging technique in the evaluation of metastasised thyroid carcinoma. Administration of recombinant human thyrotropin (rhTSH, Thyrogen®) increases the diagnostic yield of this procedure. Here we present a 64-year-old male who was followed for Hürthle cell carcinoma of the thyroid with several intrapulmonary metastases. He developed sudden complaints of neck pain following rhTSH administration as part of the routine preparation for a diagnostic ¹8FDG-PET÷CT procedure. This investigation subsequently revealed a previously undetected metastatic lesion in the first cervical vertebra, with no signs of spinal cord compression. Treatment with a nonsteroidal anti-inflammatory drug reduced the symptoms sufficiently, and a few weeks later the neurosurgeon performed a complete resection of the metastasis. It is likely that the symptoms were caused by oedema and÷or increased blood flow to the lesion. Physicians should be aware that rhTSH administration to patients with disseminated thyroid carcinoma may lead to sudden onset of symptoms caused by previously occult metastases.

Absence of bone marrow toxicity in elderly patients treated with recombinant human thyroid-stimulating hormone and empirically dosed radioiodine for thyroid cancer.

OBJECTIVES: The purpose of this paper is to evaluate the rate of clinically significant bone marrow toxicity in elderly patients after recombinant human thyroid-stimulating hormone (rhTSH) and empirically dosed radioiodine therapy for thyroid cancer. METHODS: This is a retrospective review of 15 patients with differentiated thyroid cancer that were at least 70 years old at the time of their first radioiodine treatment at our institution administered by the authors under a protocol involving an empiric dose prescription and preparation with rhTSH rather than hypothyroidism. The median dose per administration was 203 mCi and the median total dose per patient was 234 mCi. One third of the patients had at least 1 positive posttreatment whole-body scan and the other two thirds all had negative posttreatment whole-body scans. The primary study endpoint was a red cell, white cell, or platelet count below the lower limit of the normal range that produced symptoms or resulted in a recommendation for treatment. Complete blood count follow-up was at least 1 year in all patients, with a median value of 4 years. RESULTS: There was no evidence of clinically important bone marrow toxicity from radioiodine therapy in the patients in this study. No patient required treatment for anemia, leucopenia, or thrombocytopenia. CONCLUSIONS: In patients with normal renal function, clinically significant bone marrow toxicity from radioiodine therapy is highly unlikely with rhTSH preparation and empiric dosing with <250 mCi per administration and total cumulative doses <350 mCi.

Potential use of recombinant human thyrotropin in the treatment of distant metastases in patients with differentiated thyroid cancer.

OBJECTIVE: In order to effectively treat differentiated thyroid cancer (DTC) with radioiodine (RAI) it is necessary to raise serum TSH levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH). The goal of this review is to present current data on the relative efficacy and side effects profile of rhTSH-aided versus THW-aided RAI therapy for the treatment of patients with distant metastases of DTC. METHODS: We have searched the PubMed database for articles including the keywords "rhTSH", "thyroid cancer", and "distant metastases" published between January 1, 1996 and January 7, 2012. As references, we used clinical case series, case reports, review articles, and practical guidelines. RESULTS: Exogenous stimulation of TSH is associated with better quality of life because it obviates signs and symptoms of hypothyroidism resulting from endogenous TSH stimulation. The rate of neurological complications after rhTSH and THW-aided RAI therapy for brain and spine metastases is similar. The rate of leukopenia, thrombocytopenia, xerostomia, and pulmonary fibrosis is similar after preparation for RAI treatment with rhTSH and THW. There is currently a controversy regarding RAI uptake in metastatic lesions after preparation with rhTSH versus THW, with some studies suggesting equal and some superior uptake after preparation with THW. Analysis of available retrospective studies comparing survival rates, progression free survival, and biochemical and structural response to a dosimetrically-determined dose of RAI shows similar efficacy after preparation for therapy with rhTSH and THW. CONCLUSION: The rhTSH stimulation is not presently approved by the FDA as a method of preparation for adjunctive therapy with RAI in patients with metastatic DTC. Data on rhTSH compassionate use suggest that rhTSH stimulation is as equally effective as THW as a method of preparation for dosimetry-based RAI treatment in patients with RAI-avid metastatic DTC.

Ablation with low-dose radioiodine and thyrotropin alfa in thyroid cancer.

BACKGROUND: It is not known whether low-dose radioiodine (1.1 GBq [30 mCi]) is as effective as high-dose radioiodine (3.7 GBq [100 mCi]) for treating patients with differentiated thyroid cancer or whether the effects of radioiodine (especially at a low dose) are influenced by using either recombinant human thyrotropin (thyrotropin alfa) or thyroid hormone withdrawal. METHODS: At 29 centers in the United Kingdom, we conducted a randomized noninferiority trial comparing low-dose and high-dose radioiodine, each in combination with either thyrotropin alfa or thyroid hormone withdrawal before ablation. Patients (age range, 16 to 80 years) had tumor stage T1 to T3, with possible spread to nearby lymph nodes but without metastasis. End points were the rate of success of ablation at 6 to 9 months, adverse events, quality of life, and length of hospital stay. RESULTS: A total of 438 patients underwent randomization; data could be analyzed for 421. Ablation success rates were 85.0% in the group receiving low-dose radioiodine versus 88.9% in the group receiving the high dose and 87.1% in the thyrotropin alfa group versus 86.7% in the group undergoing thyroid hormone withdrawal. All 95% confidence intervals for the differences were within ±10 percentage points, indicating noninferiority. Similar results were found for low-dose radioiodine plus thyrotropin alfa (84.3%) versus high-dose radioiodine plus thyroid hormone withdrawal (87.6%) or high-dose radioiodine plus thyrotropin alfa (90.2%). More patients in the high-dose group than in the low-dose group were hospitalized for at least 3 days (36.3% vs. 13.0%, P<0.001). The proportions of patients with adverse events were 21% in the low-dose group versus 33% in the high-dose group (P=0.007) and 23% in the thyrotropin alfa group versus 30% in the group undergoing thyroid hormone withdrawal (P=0.11). CONCLUSIONS: Low-dose radioiodine plus thyrotropin alfa was as effective as high-dose radioiodine, with a lower rate of adverse events. (Funded by Cancer Research UK; ClinicalTrials.gov number, NCT00415233.).