Early versus delayed post-therapy whole body scintigraphy for well-differentiated thyroid carcinoma: A meta-analysis

Introduction@#No clear consensus exists as to the optimal timing for conducting whole body scintigraphy (WBS) after radioactive iodine (RAI) therapy for differentiated thyroid carcinoma. @*Objective@#This study aimed to compare the utility of early versus delayed post-therapy WBS in identifying residual lesions and metastases.@*Methods@#A systematic review of existing literature was done, yielding 6 observational studies relevant to the subject. Meta-analyses were done comparing lesion detecting rates of early (3-4 days post-RAI) and delayed (7-11 days post-RAI) post-therapy WBS for thyroid remnants and metastases in the lymph nodes, lungs, and bone using a random-effects model with odds ratios (OR) and 95% confidence intervals (CIs). A subgroup analysis was also done relating to the type of collimator used in imaging.

High- vs. low-dose radio-iodine therapy for initial thyroid remnant ablation in post-thyroidectomized patients with non-metastatic differentiated thyroid cancer: A meta-analysis

@#The use of high- or low-dose radio-iodine therapy (RAIT) for initial thyroid remnant ablation in post-thyroidectomised patients diagnosed with differentiated thyroid cancer (DTC) with no distant metastases has long been a subject of much debate. Meta-analyses and systematic reviews have been previously made using both randomised control trials (RCTs) and observational studies without due regard to differences in study design. Hence, amore focused meta-analysis of available RCTs alone was conducted to determine the presence of a compelling difference between the initial remnant ablation success rates of high- and low-dose RAIT in post-thyroidectomised DTC patient without distant demtastases. An extensive search of PubMed and Cochrane Central register of RCTs (up to August 2013) was performed by two reviewers, which was completed by hand search of referencesfrom releveangt articles and review papers published from 1996 to 2012. The two reviewers independtly selected eligible studies, with disagreement resolved by consensus. The inclusion criteria were as follows: (a) randomised controlled trials, (b) post-thyroidectomised adult subjects diagnosed with well differentiated thyroid cancer and no evidence of distant metastases, and (c) subject randomisation into 30-50 mCi or 100 mCi 131I treatment groups. Studies were exluded if (a) the full text of the study is not available, (b) the study is in another language other than English, and (c) if the data on relative risk was not available or could not be derived from the study. Of eight published RCTs on radio-iodine therapy as of August 2013, only 5 were eligible for this meta-analysis; namely those by JOhansen et al. (1991), Bal et al. (1996), Zaman et al. (2006), Maenpaa et al. (2008) and Caglar et al. (2012). The same two reviewers independenty extracted data from the full text of the selected five studies. Two-by-two tables comparing frequencies of successful and failed remnant ablation using low-dose (30-60 mCi) and high-dise (100 mCi) RAIT were derived from the published results of the included studies, and the weighted and pooled relative risks for successful remnant ablation were computed via the Mantel-Haenszel method using a fixed effects model (cx = 5%). Subgroup analyses were performed based on different definitions of a successful remnant ablation. The pooled relative risk (-0.03) was statistically insignificant (p=0.54) and had poor precision (95% confidence interval of {-0.12,0.06}) even when adjustments to the varied definitions of a successful ablation were performed. Thus, using available RCTs that compare high- and low-dose RAIT for remnant ablation of DTC, there is an apparent trend favoring higher success rates using high-dose RAIT. However, the lack of well designed RCTs precludes recommending high-dose initial RAI ablation, and encourages the present practice of individualized.

Factors That Influence TSH Levels after Thyrogen Injection before RAI Therapy / 대한내분비외과학회지

PURPOSE: Radioactive iodine therapy was used for detection and destruction of remnant normal of malignant thyroid tissue after thyroidectomy for differentiated thyroid gland cancer. To achieve a high level of TSH, discontinuation of levothyroxine is required. Discontinuation of L-T4 causes hypothyroidism, serious adverse impacts on patients, therefore, rhTSH is used. The aim of this study was to evaluate the factors influencing serum peak TSH levels after administration of rhTSH in patients with thyroid papillary carcinoma. METHODS: Retrospective review was conducted of 249 patients who underwent total thyroidectomy and subsequent RAI therapy at Kangbuk Samsung Hospital between October 2008 and February 2014. We divided patients into two groups according to the stimulated serum TSH level after administration of rhTSH (Group 1: TSH or =30). Clinicopathological characteristics were compared between the two groups. RESULTS: Serum peak TSH was negatively related to height, weight, BSA, and BMI, and positively related to LBM. A non-significant negative correlation was found between serum peak TSH and body composition. CONCLUSION: Patients' weight, height, BMI, BSA, and LBM were not associated with serum peak TSH after rhTSH administration. More pharmakokinetic study of rhTSH is needed in order to find correlation between pharmacokinetic factors and TSH level.

Enhanced Effect of Iodide - Uptake in Thyroid Carcinoma Cells by Infecting Adenovirus - Human Sodium Iodide Symporter (Ad - hNIS) / 대한내분비학회지

BACKGROUND: The sodium-iodide-symporter (NIS) is a plasma membrane glycoprotein with 13 putative transmembrane domains, which is responsible for concentrating iodide into the thyroid by an active transport and provides the mechanism for radioactive-iodine (RAI) therapy for thyroid cancer. However, undifferentiated thyroid cancers and about 2050% of differentiated thyroid cancers do not take up the RAI at therapeutic dose. The NIS has been cloned from rat and human (hNIS) and characterized recently. In an attempt to develop a new therapeutic strategy using hNIS gene for improving the efficacy of RAI therapy in thyroid cancers, we have constructed a recombinant adenovirus encoding the hNIS (Ad-hNIS) and tested its function by an iodide uptake by infecting human thyroid cancer cells. METHODS: RT-PCR was performed to measure an intrinsic hNIS expression in thyroid cancer cell lines, such as NPA, FRO and ARO. To generate the hNIS adenovirus, hNIS cDNA was isolated and ligated into Swa I site of cosmid shuttle vector (pAxCAwt). We have produced recombinant adenovirus by co-transfecting the cosmid with DNA-TPC to 293 cell line. Adenovirus that express (beta-Galactosidase (LacZ) was also prepared by the similar strategy. Adenovirus infection efficiency was measured in three thyroid cancer cell lines. Finally, 24 hours after infection of ad-hNIS into the cells, I125-uptake was measured. RESULTS: Endogenous hNIS expression was detected only in FRO cells but not in NPA, ARO and Hela cells by RT-PCR. X-Gal staining after infection of Ad-LacZ to thyroid cancer cell (NPA, ARO, FRO) showed that an infection rate in ARO cells was 98.5+0.5%, 97.0+0.2% in FRO cells and 75.5+5.0% in NPA cells. We selected ARO cells for the infection of Ad-hNIS due to the highest infection efficiency and the absence of endogenous hNIS expression. When ARO cells were infected with the ad-hNIS, I125 uptake was increased 504+6.4%. CONCLUSION: Overexpression of hNIS gene in thyroid cancer cells elicited over 5 fold increase in I-uptake, suggesting that the Ad-hNIS infection to the thyroid cancer cells may improve the efficiency of radioactive iodine therapy.