Search

Purpose: The aim of this study was to assess the potential role of thyroglobulin (Tg) kinetics in predicting 2-[ 18 F]-FDG-PET/CT results and overall survival (OS) in patients affected by differentiated thyroid carcinoma (DTC) and suspected recurrence., Methods: On hundred and thirty-nine patients were retrospectively included. All patients underwent 2-[ 18 F]-FDG-PET/CT due to detectable Tg levels and negative [ 131 I] whole-body scan. The last two consecutive serum Tg measurements before PET/CT were used for Tg-doubling time (TgDT) and Tg-velocity (Tg-vel) calculation. Receiver operating characteristic (ROC) curves were used to determine the optimal cutoff points for Tg, TgDT and Tg-vel for predicting PET/CT results., Results: One hundred and fifteen (83%) patients had positive PET/CT for DTC recurrence, while the remaining 24 (17%) negative. Stimulated Tg before PET and Tg-vel were significantly higher in patients with a positive PET/CT scan than negative scan (average Tg 190 vs 14 ng/mL, p = 0.006; average Tg-vel 4.2 vs 1.7 ng/mL/y, p < 0.001). Instead, TgDT was significantly shorter in positive scan (average TgDT 1.4 vs 4.4 years, p < 0.001). ROC curve analysis revealed the best Tg, TgDT and Tg-vel cutoff of 18 ng/mL,1.36 years and 1.95 ng/mL/y. In patients with Tg<18 ng/mL, the PET/CT detection rate was significantly lower in patients with low Tg-vel (p = 0.018) and with long TgDT (p = 0.001). ATA class risk, PET/CT results and Tg before PET were confirmed to be independent prognostic variables for OS., Conclusions: Tg kinetics may help to predict 2-[ 18 F]-FDG-PET/CT results in DTC patients with negative [ 131 I]WBS and detectable Tg, especially in case of low-moderate Tg., (© 2021. The Author(s).)

Objectives: The 2015 American Thyroid Association (ATA) guidelines called for significantly more selective 131 I therapy in patients with low-risk differentiated thyroid cancer (DTC). We hypothesized that application of these guidelines would significantly reduce the 131 I activity utilized by an academic tertiary hospital in Jordan., Methods: All DTC patients managed at Jordan University Hospital (JUH) between 1/2009 and 6/2019 were classified according to the 2015 ATA risk category and 131 I activity was assigned accordingly. The actual 131 I activity administered was compared with that recommended by the 2015 ATA guidelines., Results: In total, 135/182 DTC patients (74.2%) managed at JUH underwent 131 I therapy. Of those, 58 (43%) had ATA low-, 58 (43%) intermediate-, and 19 (14%) high-risk disease. The low-, intermediate-, and high-risk DTC patients received an average (±SD) initial 131 I activity of 3.53 ± 0.95, 4.40 ± 1.49, and 5.06 ± 2.52 GBq, respectively. Withholding 131 I therapy altogether in the 2015 ATA low-risk patients would result in decreasing the 131 I activity in the overall patient population by 37%. Withholding 131 I therapy only in low-risk papillary thyroid microcarcinomas while administering 1.11 GBq of 131 I to other low-risk patients would result in 28% reduction of 131 I., Conclusion: This study demonstrates a significant reduction in 131 I therapeutic activity that would be given to DTC patients in an academic tertiary setting in Jordan, following acceptance of the 2015 ATA recommendations. Institutions that adopted the 2015 ATA guidance should measure outcomes in comparison to their historical controls and report those findings, while long-term results of randomized controlled trials are forthcoming., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose: To investigate the potential role of serum thyroglobulin doubling time (TgDT) in predicting 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) PET/CT results in patients affected by differentiated thyroid carcinoma (DTC) who demonstrated a combination of positive Tg but a negative [ 131 I] whole-body scan ([ 131 I]-WBS)., Materials and Methods: Inclusion criteria were (1) prior [ 131 I] treatment for DTC, (2) negative subsequent [ 131 I]-WBS, (3) no interfering anti-Tg antibodies, (4) three consecutive Tg measurements under the thyroid hormone replacement therapy to calculate TgDT before 2-[ 18 F]FDG PET/CT, and (5) at least 6 months of clinical and/or imaging follow-up to ascertain the diagnosis. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used to identify the optimal cutoff point for the last stimulated Tg and TgDT prior to [ 18 F]FDG PET/CT., Results: One hundred and thirteen patients were included. Seventy-four (65%) patients had positive [ 18 F]FDG PET/CT for DTC recurrence, while the remaining 39 (35%) negative. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of [ 18 F]FDG PET/CT were 92%, 94%, 97%, 87%, and 93%. Patients with positive [ 18 F]FDG PET/CT had higher Tg and TgDT than those with negative PET/CT. ROC curve analysis revealed an optimal Tg cutoff of 19 ng/mL (sensitivity 78%, specificity 85%, AUC = 0.844) and TgDT of 2.5 years (sensitivity 93%, specificity 87%, AUC = 0.911). TgDT threshold of 2.5 years predicted significantly (p = 0.023) better than Tg level PET/CT results., Conclusions: The diagnostic performance of [ 18 F]FDG PET/CT could be significantly improved when TgDT is less than or equal to 2.5 years, as compared with using the absolute Tg level.

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of 131 I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the 131 I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low 131 I activity. 131 I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of 131 I activity for adjuvant treatment is controversial, but experts reached a consensus that the 131 I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for 131 I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current 131 I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment., (© 2020 UICC.)

Background: Thyroid lobectomy (TL) has been proposed as definitive surgical treatment for papillary thyroid cancers (PTC) up to 4 cm. This study evaluates the use and appropriateness of TL for T1b and T2 PTC., Study Design: The National Cancer Database was interrogated for adult patients having TL for T1b-T2 PTC between 2004 and 2014. Patients who should have undergone total thyroidectomy (TT) instead of lobectomy based on high-risk tumor features were identified. The 2 groups were compared for clinical and demographic characteristics, and overall survival., Results: Of 8,083 patients undergoing lobectomy, 1,552 patients had high-risk features and should have undergone TT. These included 194 with cN1, 571 with pN1, 307 with lymphovascular invasion (LVI), 645 with extra thyroidal extension (ETE), 567 with positive margins, 42 with poorly differentiated PTC, and 25 with M1 disease. At 10 years of follow-up, 92.4% of appropriate lobectomy (aTL) patients were alive compared with 88.5% of inappropriate lobectomy (iTL) patients (p < 0.001). On univariate and multivariable Cox survival analysis, age greater than 45 years, male sex, comorbidities, government or no insurance, low income, and tumor size >2 cm were associated with poorer survival (all p < 0.05). Thyroid lobectomy patients with high-risk features had significantly higher mortality on unadjusted (hazard ratio [HR] 1.98, 95% CI 1.52 to 2.59, p < 0.001) and adjusted survival analysis (HR 1.97, 95% CI 1.51 to 2.58, p < 0.001). Total thyroidectomy with radioiodine treatment had improved overall survival in comparison to iTL (HR 0.65, 95% CI 0.51 to 0.83, p < 0.001)., Conclusions: A substantial number of patients (19.2%) with tumor size >1 cm and high-risk features undergo thyroid lobectomy for PTC. Exclusion of high-risk features is important when adopting lobectomy as the definitive surgical therapy for T1b and T2 PTC because they have a potential adverse effect on long-term survival., (Copyright © 2019 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

This review of radioactive iodide treatment (RAIT) extends from historical origins to its modern utilization in differentiated thyroid cancer (DTC). The principles embedded in the radiotheragnostics (RTGs) paradigm are detailed. The diverse approaches in current practice are addressed, and this broad variability represents a major weakness that erodes our specialty's trust-based relationship with patients and referring physicians. The currently developing inter-specialty collaboration should be hailed as a positive change. It promises to clarify the target-based terminology for RAIT. It defines RAIT of post total thyroidectomy (PTT), presumably benign thyroid as 'remnant ablation' (RA). 'Adjuvant treatment' (AT) referrers to RAIT of suspected microscopic DTC that is inherently occult on diagnostic imaging. RAIT directed at DTC lesion(s) overtly seen on diagnostic imaging is termed 'treatment of known disease' (TKD). It was recently recognized that a 'recurrent' DTC is actually occult residual DTC in the majority of cases. Thyroglobulin with remnant uptake concord (TRUC) method (aka Tulchinsky method) was developed to validate that a benign remnant in the post-thyroidectomy neck bed, as quantified by the RAI uptake, is concordant with a measured thyroglobulin (Tg) level at the time of the initial post-thyroidectomy evaluation. It allows recognition of occult residual DTC contribution to post-thyroidectomy Tg. Case examples demonstrate the application of the TRUC method for a logical selection of a specific RAIT category, using imaging-guided identification and management of RAI-avid versus RAI-nonavid residual DTC, i.e. the radiotheragnostics paradigm., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

July 1, 2019, JAMA Internal Medicine released online an article authored by Kitahara et al entitled "Association of radioactive iodine treatment with cancer mortality in patients with hyperthyroidism." The Altmetric Attention Score, a global indicator of interest from lay public and colleagues, skyrocketed to 223 by July 7, placing the article in the top 5% of all scored reports. The overall perception of death from cancer risk associated with I is inflated and not supported by evidence. As co-authors of this article, we offer previously unpublished data and analysis that (1) disputes clinical significance of the associated risk from I and (2) shows, again, that antithyroid drugs carry a statistically significant and a much more obvious cancer death risk.