Sodium Iodide Symporter (NIS) in the Management of Patients with Thyroid Carcinoma

Thyroid Hormone Withdrawal versus Recombinant Human TSH as Preparation for I-131 Therapy in Patients with Metastatic Thyroid Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Differentiated thyroid carcinoma (DTC) is characterized by an excellent prognosis with a 10-year survival rate > 90%. However, when DTC develops in a metastatic form, it has been shown to significantly impact patient survival and quality of life. Although I-131 has been shown to be an effective therapy in patients with metastatic DTC, whether its efficacy after recombinant human TSH (rhTSH) is comparable to endogenous TSH stimulation by thyroid hormone deprivation (THW) is still debated. Our present study was prompted to compare clinical results obtained in metastatic DTC by I-131 administered after rhTSH and THW stimulation protocols, respectively.

METHODS

A systematic search on PubMed, Web of Science, and Scopus was performed from January to February 2023. Pooled risk ratios with 95% CI were determined for evaluating the initial response after to I-131 therapy after preparation with rhTSH or THW and the disease progression. To track the accumulation of evidence and reduce type I errors because of small data, a cumulative meta-analysis was performed. A sensitivity analysis was also performed to examine the impact of individual studies on overall prevalence results.

RESULTS

Ten studies were included with a total of 1929 patients pre-treated with rhTSH (n = 953) and THW (n = 976), respectively. The cumulative data of our systematic review and meta-analysis showed an increase in the risk ratio over the years without any change in favour of a pre-treatment or the other on the effectiveness of I-131 therapy of metastatic DTC.

CONCLUSIONS

Our data suggest that pretreatment with rhTSH or THW has no significant impact on the effectiveness of I-131 therapy for metastatic DTC. This implies that concerns about the use of one or the other pretreatment should be deferred to clinical evaluations made considering patient characteristics and reduction in side effects.

Managing radioiodine refractory thyroid cancer: the role of dosimetry and redifferentiation on subsequent I-131 therapy

Poor responses to iodine-131 (I-131) therapy can relate to either low iodine uptake and retention in thyroid cancer cells or to increased radioresistance. Both mechanisms are currently termed radioactive iodine (RAI)-refractory (RAI-R) thyroid cancer but the first reflects unsuitability for I-131 therapy that can be evaluated in advance of treatment, whereas the other can only be identified post hoc. Management of both represents a considerable challenge in clinical practice as failure of I-131 therapy, the most effective treatment of metastatic thyroid cancer, is associated with a poor overall prognosis. The development of targeted therapies has shown substantial promise in the treatment of RAI-R thyroid cancer in progressive patients. Recent studies show that selective tyrosine kinase inhibitors (TKIs) targeting B-type rapidly accelerated fibrosarcoma kinase (BRAF) and mitogen-activated protein kinase (MEK) can be used as redifferentiation agents to re-induce RAI uptake, thereby (re)enabling I-131 therapy. The use of dosimetry prior- and post-TKI treatment can assist in quantifying RAI uptake and improve identification of patients that will benefit from I-131 therapy. It also potentially offers the prospect of calculating individualized therapeutic administered activities to enhance efficacy and limit toxicity. In this review, we present an overview of the regulation of RAI uptake and clinically investigated redifferentiation agents, both reimbursed and in experimental setting, that induce renewed RAI uptake. We describe the role of dosimetry in redifferentiation and subsequent I-131 therapy in RAI-R thyroid cancer, explain different dosimetry approaches and discuss limitations and considerations in the field.

Analysis of differences of ultrasound features in different courses of thyroid carcinoma

OBJECTIVE

To explore the changes of ultrasound features in patients with different courses of thyroid carcinoma, so as to provide a theoretical basis for the clinical treatment and diagnosis of thyroid carcinoma.

METHODS

A total of 160 patients with thyroid carcinoma treated in our hospital were enrolled and divided into the early stage group (n=76) and the advanced stage group (n=84) according to the results of pathological examination, and further grouped into the lymph node metastasis group (n=78) and the non-metastasis group (n=82). Another 80 patients with benign thyroid disease were enrolled as the benign group. All the enrolled subjects were subjected to ultrasound examination, and the differences of ultrasound features were compared between the different groups.

RESULTS

The average diameter of tumour and the proportion of nodular calcification and heterogeneous echo in the advanced stage group were significantly higher than those in the early stage group (P<0.05). The proportions of nodular calcification, heterogeneous echo, unsmooth margins, the aspect ratio of 1 or above, and irregular shapes in the malignant group were significantly higher than those in the benign group (P<0.05). The proportions of nodular calcification, heterogeneous echo, unsmooth margins, the aspect ratio of 1 or above, irregular shapes, multiple nodules, the largest diameter greater than 10 mm, rich blood flow, and absent halo in the lymph node metastasis group were significantly higher than those in the non-metastasis group (P<0.05).

CONCLUSION

There were significant differences of ultrasound features in the different courses of thyroid carcinoma. Ultrasound examination can provide important reference for later clinical diagnosis and treatment.

Peptide Receptor Radionuclide Therapy in Patients With Differentiated Thyroid Cancer: A Meta-analysis

PURPOSE

As patients with progressive medullary thyroid cancer (MTC) and radioiodine-refractory metastatic differentiated nonmedullary thyroid cancer (DTC) have poor prognoses and present therapeutic challenges, peptide receptor radionuclide therapy (PRRT) targeting the somatostatin receptor provides a promising option. This meta-analysis evaluated the therapeutic effects and outcomes of PRRT in differentiated thyroid cancer.

PATIENTS AND METHODS

PUBMED, EMBASE, CINAHL, SCOPUS, and COCHRANE were systematically searched using appropriate key words. The primary therapeutic effect was the radiological response after PRRT, and the objective response rate (ORR) and disease control rate (DCR) were identified in MTC and DTC, respectively. The outcome of serious adverse events (grade 3 or 4), additional therapeutic effects of F-FDG PET/CT and biochemical (calcitonin and thyroglobulin) responses, and radionuclides for PRRT were assessed as subgroup analyses. The parameters were generated as pooled proportions.

RESULTS

Eleven articles with 165 patients were included (98 patients with MTC and 67 patients with DTC). PRRT achieved pooled proportions of ORR in 8.53% to 15.61%, DCR in 53.95% to 59.99%, and serious adverse events in 2.79% to 2.82% in MTC and DTC patients. F-FDG PET/CT and biochemical responses revealed similar results as the radiological response. Lu-based PRRT (ORR, 11.48%-24.52%; DCR, 61.47%-67.26%) showed better therapeutic effects than Y-based PRRT (ORR, 6.98%-13.82%; DCR, 50.86%-57.29%).

CONCLUSIONS

This meta-analysis suggests that PRRT could be a potential and safe strategy for MTC and DTC. In particular, PRRT with Lu exhibited improved therapeutic effects relative to PRRT with Y.