Differentiated thyroid carcinoma: defining new paradigms for postoperative management

Impact of a mobile health intervention based on multi-theory model of health behavior change on self-management in patients with differentiated thyroid cancer: protocol for a randomized controlled trial

Introduction

Theoretical models of health behavior are important guides for disease prevention and detection, treatment and rehabilitation, and promotion and maintenance of physical and mental health, but there are no intervention studies related to differentiated thyroid cancer (DTC) that use theoretical models of health as a guide. In this study, we used a microblogging platform as an intervention vehicle and mobile patient-doctor interactive health education as a means of intervention, with the aim of improving the health behaviors of DTC patients as well as the corresponding clinical outcomes.

Methods

This research project is a quantitative methodological study, and the trial will be a single-blind, single-center randomized controlled trial conducted at the Fourth Hospital of Harbin Medical University in Harbin, Heilongjiang Province. The study subjects are patients over 18 years of age with differentiated thyroid cancer who were given radioactive iodine-131 therapy as well as endocrine therapy after radical surgery for thyroid cancer. The intervention group will receive MTM-mhealth, and the realization of health education will rely on the smart terminal WeChat platform. Routine discharge education will be given to the control group at discharge. The primary outcome will be change in thyroid-stimulating hormone (TSH) from baseline and at 3 and 6 months of follow-up, and secondary outcomes will include change in self-management behavior, social cognitive and psychological, and metabolic control.

Discussion

This study will explore a feasible mHealth intervention program applied to a population of DTC patients using the Multi-theory model of health behavior change (MTM) as a guide, with the aim of evaluating the MTM-based intervention program for clinical outcome improvement in DTC patients, as well as determining the effectiveness of the MTM-based intervention program in improving self-management skills in DTC patients. The results of this study will indicate the feasibility as well as the effectiveness of the application of health theoretical modeling combined with mHealth applications in disease prognostic health management models, and provide policy recommendations and technological translations for the development of mobility-based health management applications in the field of health management.

Long-term prognostic analysis of children and adolescents with differentiated thyroid carcinoma based on therapeutic response to initial radioiodine therapy

Background

The clinical features and prognosis of children and adolescents with differentiated thyroid carcinoma (caDTC) are different from that of adults. Postoperative radioiodine therapy (RIT) was recommended for some intermediate and high risk caDTC patients. The objective of this study was to evaluate the long-term prognosis of pediatric caDTC patients with different responses to initial RIT and to explore the related influencing factors.

Methods

All subjects were assigned to no clinical evidence of disease (NED) group, biochemical persistent disease (BPD) group, or structural/functional persistent disease (S/FPD) group based on the therapeutic response to initial RIT. Then, disease status was evaluated in all three groups at the last follow-up using ATA guidelines. Meanwhile, disease-free survival (DFS) for NED group and the progression-free survival (PFS) for the BPD and S/FPD groups were also assessed.

Results

117 subjects were divided into NED group (n=29), BPD group (n=48) and S/FPD group (n=34) after initial RIT. At the last follow-up, excellent response (ER), indeterminate response (IDR), biochemically incomplete response (BIR) and structurally incomplete response (SIR) rates were 93.10%, 6.90%, 0% and 0% in NED group; 29.17%, 25.00%, 43.75% and 2.08% in BPD group; and 11.77%, 2.94%, 0%, and 85.29% in S/FPD group. The 5-year DFS rate in NED group was 95.5%. The 5-year PFS rates in BPD and S/FPD groups were 79.2% and 48.6%, respectively. For children with structural or functional lesions, longer PFS were found in male children with 131I-avid lesions, and post-operative stimulated serum thyroglobulin (sti-Tg) < 149.80 ng/ml.

Conclusion

The response to initial RIT could be helpful for defining subsequent treatment and follow-up strategies for caDTC patients. Post-operative sti-Tg and 131I-avidity of lesions are correlated with PFS.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

The Role of the Kinase Inhibitors in Thyroid Cancers

Thyroid cancer is the most common endocrine malignancy, accounting for about 3% of all cancer cases each year worldwide with increasing incidence, but with the mortality remaining stable at low levels. This contradiction is due to overdiagnosis of indolent neoplasms identified by neck ultrasound screening that would remain otherwise asymptomatic. Differentiated thyroid carcinomas (DTCs) are almost curable for 95% with a good prognosis. However, 5% of these tumours worsened toward aggressive forms: large tumours with extravasal invasion, either with regional lymph node or distant metastasis, that represent a serious clinical challenge. The unveiling of the genomic landscape of these tumours shows that the most frequent mutations occur in tyrosine kinase receptors (RET), in components of the MAPK/PI3K signalling pathway (RAS and BRAF) or chromosomal rearrangements (RET/PTC and NTRK hybrids); thus, tyrosine-kinase inhibitor (TKI) treatments arose in the last decade as the most effective therapeutic option for these aggressive tumours to mitigate the MAPK/PI3K activation. In this review, we summarize the variants of malignant thyroid cancers, the molecular mechanisms and factors known to contribute to thyroid cell plasticity and the approved drugs in the clinical trials and those under investigation, providing an overview of available treatments toward a genome-driven oncology, the only opportunity to beat cancer eventually through tailoring the therapy to individual genetic alterations. However, radiotherapeutic and chemotherapeutic resistances to these anticancer treatments are common and, wherever possible, we discuss these issues.

Multikinase inhibitors for the treatment of radioiodine refractory thyroid cancer: what have we learned from the 'real-world' experience?

PURPOSE OF REVIEW

Several molecularly targeted drugs for treating radioiodine resistant differentiated thyroid carcinomas (RAIR-DTC) have been identified. Among these, sorafenib and lenvatinib have been approved for clinical use in many countries. The present review will analyze efficacy and safety 'real-world' data (RWD) emerging after their commercialization.

RECENT FINDINGS

RWDs confirmed sorafenib and lenvatinib efficacy in terms of progression-free survival and, perhaps, overall survival improvement in patients with RAIR-DTC. Lenvatinib performance in RWDs appeared somehow lower than in randomized clinical trials (RCT), probably because the decision to start treatment in 'real life' was made when patients were in worse clinical conditions than in RCTs. Concerning safety, RWD studies corroborated RCT evidence of elevated overall and serious adverse event incidence. Notably, adverse events were manageable in most cases with appropriate treatment or dose reduction/interruption, so that the need for definitive withdrawal was limited. The suitability of multikinase inhibitors (MKI) as salvage therapy in RAIR-DTCs was also confirmed by RWD experience, at least for lenvatinib in the second-line setting.

SUMMARY

RWD analysis has corroborated RCT results in terms of MKI efficacy for both first-line and salvage treatment in patients with RAIR-DTC. The safety profiles emerging from RWDs seem to justify the caution recommended by most scientific guidelines.

Personalized management of differentiated thyroid cancer in real life - practical guidance from a multidisciplinary panel of experts

PURPOSE

The standard of care for differentiated thyroid carcinoma (DTC) includes surgery, risk-adapted postoperative radioiodine therapy (RaIT), individualized thyroid hormone therapy, and follow-up for detection of patients with persistent or recurrent disease. In 2019, the nine Martinique Principles for managing thyroid cancer were developed by the American Thyroid Association, European Association of Nuclear Medicine, Society of Nuclear Medicine and Molecular Imaging, and European Thyroid Association. In this review, we present our clinical practice recommendations with regard to implementing these principles in the diagnosis, treatment, and long-term follow-up of patients with DTC.

METHODS

A multidisciplinary panel of five thyroid cancer experts addressed the implementation of the Martinique Principles in routine clinical practice based on clinical experience and evidence from the literature.

RESULTS

We provide a suggested approach for the assessment and diagnosis of DTC in routine clinical practice, including the use of neck ultrasound, measurement of serum thyroid-stimulating hormone and calcitonin, fine-needle aspiration, cytology, and molecular imaging. Recommendations for the use of surgery (lobectomy vs. total thyroidectomy) and postoperative RaIT are also provided. Long-term follow-up with neck ultrasound and measurement of serum anti-thyroglobulin antibody and basal/stimulated thyroglobulin is standard, with ¹²³/¹³¹I radioiodine diagnostic whole-body scans and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography suggested in selected patients. Management of metastatic DTC should involve a multidisciplinary team.

CONCLUSIONS

In routine clinical practice, the Martinique Principles should be implemented in order to optimize clinical management/outcomes of patients with DTC.

Combination of peroxisome proliferator-activated receptor gamma and retinoid X receptor agonists induces sodium/iodide symporter expression and inhibits cell growth of human thyroid cancer cells

BACKGROUND

Thyroid tumors are the most frequent neoplasm of the endocrine system. The major treatment is surgical intervention followed by radioiodine therapy. The sodium/iodide symporter (NIS) has positive expression in thyroid carcinomas with good prognoses and plays a critical role in radioiodine therapy response. Low expression of NIS always leads to tumor recurrence or treatment failure. Redifferentiation therapy is more tumor specific than chemotherapy. Peroxisome proliferator-activated receptor gamma (PPARγ) agonists and retinoids are two types of redifferentiating agents. In this study, we examined whether the PPARγ agonist rosiglitazone and retinoid X receptor (RXR) agonist bexarotene could increase NIS expression and exhibit anticancer activity in human thyroid cancer cells.

METHODS

Using a TCGA data set, we analyzed the expression of NIS (SLC5A5), PPARγ, and RXR in clinical thyroid tumors and assessed their correlations with the relapse-free survival (RFS) of thyroid tumor patients. Moreover, two human thyroid cancer cell lines, differentiated thyroid papillary BCPAP cells and follicular follicular thyroid cancer-131 cells, were treated with different concentrations of the PPARγ agonist rosiglitazone alone or in combination with the RXR agonist bexarotene. Cell growth was analyzed by the MTT assay. NIS protein expression was determined by Western blotting.

RESULTS

From analysis of the TCGA data set, we found that thyroid tumors have lower expression of both NIS (SLC5A5) and PPARγ than nontumor controls. Higher expression levels of NIS, PPARγ, and RXR are associated with higher RFS in patients with thyroid tumors. Moreover, rosiglitazone treatment reduced cell growth and increased NIS protein expression in thyroid cancer cells under normoxic or hypoxic conditions. In addition, bexarotene potentiated the effects of rosiglitazone on cell growth and NIS protein expression.

CONCLUSION

Our results suggest that the combination of PPARγ and RXR agonists has potential as a chemotherapeutic strategy for thyroid cancer.

Novel therapeutic options for radioiodine-refractory thyroid cancer: redifferentiation and beyond

PURPOSE OF REVIEW

Radioiodine-refractory thyroid cancers represent the main cause of thyroid cancer-related death. At present, targeted therapies with multikinase inhibitors represent a unique therapeutic tool, though they have limited benefit on patient survival and severe drug-associated adverse events. This review summarizes current treatment strategies for radioiodine-refractory thyroid cancer and focuses on novel approaches to redifferentiate thyroid cancer cells to restore responsiveness to radioiodine administration.

RECENT FINDINGS

We summarize and discuss recent clinical trial findings and early data from real-life experiences with multikinase-inhibiting drugs. Possible alternative strategies to traditional redifferentiation are also discussed.

SUMMARY

The current review focuses primarily on the major advancements in the knowledge of the pathophysiology of iodine transport and metabolism and the genetic and epigenetic alterations occurring in thyroid neoplasia as described using preclinical models. Results of clinical studies employing new compounds to induce thyroid cancer cell redifferentiation by acting against specific molecular targets are also discussed. Finally, we describe the current scenario emerging from such findings as well as future perspectives.

Follicular thyroid cancer and Hürthle cell carcinoma: challenges in diagnosis, treatment, and clinical management

Follicular thyroid cancer is the second most common differentiated thyroid cancer histological type and has been overshadowed by its more common counterpart-papillary thyroid cancer-despite its unique biological behaviour and less favourable outcomes. In this Review, we comprehensively review the literature on follicular thyroid cancer to provide an evidence-based guide to the management of these tumours, to highlight the lack of evidence behind guideline recommendations, and to identify changes and challenges over the past decades in diagnosis, prognosis, and treatment. We highlight that correct identification of cancer in indeterminate cytological samples is challenging and ultrasonographic features can be misleading. Despite certain unique aspects of follicular thyroid cancer presentation and prognosis, no specific recommendations exist for follicular thyroid cancer and Hürthle cell carcinoma in evidence-based guidelines. Efforts should be made to stimulate additional research in this field.

Post-treatment surveillance of thyroid cancer

An increased incidence of differentiated thyroid cancer (DTC) has resulted in an increased population of thyroid cancer survivors requiring ongoing disease surveillance. Our institution's risk-adapted surveillance strategy is based on a contemporary understanding of disease biology, guided by analysis of prognostic factors and balanced application of available surveillance modalities. The goal of this strategy is to detect recurrent disease early, identify patients who would benefit from further treatment and reduce over investigation of low-risk patients. This article describes our center's risk-stratified approach to the postoperative surveillance of patients with differentiated thyroid cancer with reference to the recent 2015 American Thyroid Association management guidelines.

Dual control of pituitary thyroid stimulating hormone secretion by thyroxine and triiodothyronine in athyreotic patients

BACKGROUND

Patient responses to levothyroxine (LT4) monotherapy vary considerably. We sought to differentiate contributions of FT4 and FT3 in controlling pituitary thyroid stimulating hormone (TSH) secretion.

METHODS

We retrospectively assessed the relationships between TSH and thyroid hormones in 319 patients with thyroid carcinoma through 2914 visits on various LT4 doses during follow-up for 5.5 years (median, IQR 4.2, 6.9). We also associated patient complaints with the relationships.

RESULTS

Under varying dose requirements (median 1.84 µg/kg, IQR 1.62, 2.11), patients reached TSH targets below 0.4, 0.1 or 0.01 mIU/l at 73%, 54% and 27% of visits. While intercept, slope and fit of linearity of the relationships between lnTSH and FT4/FT3 varied between individuals, gender, age, LT4 dose and deiodinase activity influenced the relationships in the cohort (all p < 0.001). Deiodinase activity impaired by LT4 dose significantly affected the lnTSH-FT4 relationship. Dose increase and reduced conversion efficiency displaced FT3-TSH equilibria. In LT4-treated patients, FT4 and FT3 contributed on average 52% versus 38%, and by interaction 10% towards TSH suppression. Symptomatic presentations (11%) accompanied reduced FT3 concentrations (-0.23 pmol/l, p = 0.001) adjusted for gender, age and BMI, their relationships being shifted towards higher TSH values at comparable FT3/FT4 levels.

CONCLUSIONS

Variation in deiodinase activity and resulting FT3 levels shape the TSH-FT4 relationship in LT4-treated athyreotic patients, suggesting cascade control of pituitary TSH production by the two hormones. Consequently, measurement of FT3 and calculation of conversion efficiency may identify patients with impaired biochemistry and a resulting lack of symptomatic control.

Is a second recombinant human thyrotropin stimulation test useful? The value of postsurgical undetectable stimulated thyroglobulin level at the time of remnant ablation on clinical outcome

OBJECTIVE

The management of patients with differentiated thyroid cancer (DTC) has changed in recent years, and monitoring depends on the risk of persistent/recurrent disease. The objective was to assess the prognostic value of a single stimulated thyroglobulin (Tg) measured at the time of the first radioiodine therapy (Stim-Tg1), and the utility of a second stimulated Tg measurement performed 6-12 months later (Stim-Tg2). We also examined the role of neck ultrasound (US) in the early diagnosis of recurrence.

DESIGN

This was a retrospective observational cohort study conducted in a tertiary referral hospital. Of 213 evaluated patients with DTC, 169 were finally included.

METHODS

Measurement of Stim-Tg1, Stim-Tg2 and neck US.

RESULTS

Stim-Tg1 was undetectable in 71 of 169 patients (42%). All of them (71/71) continued to have negative Stim-Tg2. Seventy of 71 had an excellent response to the first treatment. Sixty-eight of 71 had no evidence of disease after an average follow-up of 7·2 years. In patients with detectable Stim-Tg1 (98/169; 58%), Stim-Tg2 became negative in 40. The negative predictive value (NPV) of Stim-Tg1 was 0·96. The optimal Stim-Tg1 cut-off level for identifying persistence was 3·65 ng/ml. Recurrence was detected in 14 patients. Neck US was useful for identifying local recurrence (13/14; 92·85%).

CONCLUSIONS

Stim-Tg1 is a reliable marker with a high NPV. A second stimulation test should be avoided in patients with negative Stim-Tg1. In patients with biochemical persistence, Stim-Tg2 is useful for confirming/ruling out final status. Neck US plays a valuable role in the early diagnosis of recurrence.

Incremental Value of a Dedicated Head and Neck Acquisition during 18F-FDG PET/CT in Patients with Differentiated Thyroid Cancer

Objectives

¹⁸F-FDG-PET/CT is a useful tool used to evidence persistent/recurrent disease (PRD) in patients with differentiated thyroid cancer and iodine-refractory lesions. The aim of this study was to compare the diagnostic value at the cervical level of the routine whole-body (WB) acquisition and that of a complementary head and neck (HN) acquisition, performed successively during the same PET/CT study.

Methods

PET/CT studies combining WB and HN acquisitions performed in 85 consecutive patients were retrospectively reviewed by two nuclear medicine physicians. ¹⁸F-FDG uptake in cervical lymph nodes (LN) or in the thyroid bed was assessed. Among the 85 patients, the PET/CT results of the 26 who subsequently underwent neck surgery were compared with surgical and pathological reports. The size of each largest nodal metastasis was assessed by a pathologist.

Results

In the 85 patients, inter-observer agreement was excellent for both WB and HN PET/CT interpretation. Of the 26 patients who underwent surgery, 25 had pathology proven PRD in the neck. Of these 25 patients, 15 displayed FDG uptake on either WB or HN PET. In these 15 patients, HN PET detected more malignant lesions than WB PET did (21/27 = 78% vs. 12/27 = 44%, P = 0.006). Node/background ratios were significantly higher on HN than on WB PET (P<0.0001). Three false-negative studies (20%) on WB PET were upstaged as true-positive on HN PET. The mean size of the largest LN metastasis was 3 mm for the LN detected neither on WB nor on HN PET, 7 mm for the metastasis detected on HN but not on WB PET, and 13 mm for those detected on both acquisitions (P = 0.0004). Receiver-Operating Characteristic analysis showed that area under the curve was higher for HN PET than for WB PET (0.97 [95%CI, 0.90–0.99] vs 0.88 [95%CI, 0.78–0.95], P = 0.009).

Conclusions

HN acquisition improves the ability to detect PRD in the neck compared with WB acquisition alone. We recommend systematically adding an HN acquisition when PET/CT is performed to detect PRD in the neck.

Thyroid Cancer in Pediatrics

Well differentiated thyroid cancer (DTC) in children is characterized by a high rate of response to treatment and low disease-specific mortality. Treatment of children with DTC has evolved toward a greater reliance on evaluation and monitoring with serial serum thyroglobulin measurements and ultrasound examinations. Radioiodine therapy is recommended for thyroid remnant ablation in high-risk patients, treatment of demonstrated radioiodine-avid local-regional disease not amenable to surgical resection, or distant radioiodine-avid metastatic disease. Sufficient time should be given for benefits of radioiodine therapy to be realized, with follow-up monitoring. Re-treatment with radioiodine can be deferred until progression of significant disease manifests.

Emerging strategies for managing differentiated thyroid cancers refractory to radioiodine

Efficient treatment of radio refractory thyroid cancer is still a major challenge. The recent identification of genetic and epigenetic alterations present in almost all differentiated tumors has revealed novel molecular targets, which can hopefully be exploited to create new treatments for these tumors. This review looks briefly at some of the innovative strategies currently being investigated for the treatment the radioiodine-resistant thyroid cancers.

Comparison of Antithyroglobulin Antibody Concentrations Before and After Ablation with 131I as a Predictor of Structural Disease in Differentiated Thyroid Carcinoma Patients with Undetectable Basal Thyroglobulin and Negative Neck Ultrasonography

BACKGROUND

Patients with differentiated thyroid carcinoma are submitted to a first assessment several months after initial therapy to evaluate their response to treatment. At that assessment, measurement of basal thyroglobulin (Tg) and antithyroglobulin antibodies (TgAb) and neck ultrasonography (US) are recommended. Serum Tg may be falsely negative in the presence of TgAb, and the management of patients with negative Tg but positive TgAb represents a challenge. The objective of this study was to correlate the variation in TgAb concentrations (comparison before and after ablation with (131)I) with the risk of structural disease.

METHODS

The sample consisted of 116 low- or intermediate-risk patients who had undetectable Tg, negative US at initial assessment, and positive TgAb 8-12 months after thyroidectomy and ablation with (131)I.

RESULTS

Comparison of TgAb concentrations before and after ablation with (131)I showed a reduction of >50% in 56 patients (group A), a reduction of <50% in 35 patients (group B), and an increase in 25 patients (group C). Metastases were detected in 5/116 (4.3%) patients during initial assessment (lymph nodes in two, pulmonary in two, and bone in one). They were diagnosed in 0/56, 2/35 (5.7%), and 3/25 (12%) patients of groups A, B, and C, respectively. During follow-up, metastases were detected in 7/111 (6.3%) patients (lymph nodes in six, and pulmonary in one). They occurred in 1/56 (1.8%), 3/33 (9%), and 3/22 (13.6%) patients of groups A, B, and C, respectively. Thus, structural disease was found in 1.8%, 14.3%, and 24% of groups A, B, and C, respectively. This rate was 4% in low-risk patients and 15.4% in intermediate-risk patients.

CONCLUSIONS

Among patients with undetectable Tg, negative US, and positive TgAb after ablation with (131)I, the frequency of structural disease was <5% in patients, with >50% reduction in TgAb. Among patients without a significant reduction in TgAb, approximately 10% of low-risk patients and >20% of intermediate-risk patients had structural disease. These results help define the indication for imaging methods other than US during initial assessment and long-term follow-up.

Nodal metastases in thyroid cancer: prognostic implications and management

The significance of cervical lymph node metastases in differentiated thyroid cancer has been controversial and continues to evolve. Current staging systems consider nodal metastases to confer a poorer prognosis, particularly in older patients. Increasingly, the literature suggests that characteristics of the metastatic lymph nodes such as size and number are also prognostic. There is a growing trend toward less aggressive treatment of low-volume nodal disease. The aim of this review is to summarize the current literature and discuss prognostic and management implications of lymph node metastases in differentiated thyroid cancer.

(124)I PET/CT in Patients with Differentiated Thyroid Cancer: Clinical and Quantitative Image Analysis

BACKGROUND

Although radioactive iodine (RAI) imaging/therapy is one of the earliest applications of theranostics, there remain a number of unresolved clinical questions as to the optimization of diagnostic techniques/protocols and improvements in patient-specific treatment planning strategies. The objectives of this study were to determine the imaging characteristics and clinical feasibility of (124)I positron emission tomography/computed tomography (PET/CT) for the determination of extent of disease and evaluation of RAI kinetics in its physiologic and neoplastic distribution in patients with differentiated thyroid cancer (DTC).

METHODS

The study was designed as a prospective phase II diagnostic trial of patients with confirmed DTC. Following adequate preparation, patients received 2 mCi (124)I in liquid form and sequential whole-body PET/CT imaging was performed at five time points (2-4 h, 24 ± 6 h, 48 ± 6 h, 72 ± 6 h, and 96 ± 6 h post-administration). All patients who had (124)I imaging subsequently underwent RAI treatment with (131)I, with administered activities ranging from 100 to 300 mCi. Post-treatment scans were obtained 5-7 days after RAI treatment. A by-patient and by-lesion analysis of the (124)I images was performed and compared with the post-treatment (131)I scans as well as F-18 FDG PET/CT images. Quantitative image analysis was also performed to determine the total functional volume (mL), activity per functional volume (μCi/mL), and cumulated activity (μCi/h) for remnants, salivary glands, and nodal metastases.

RESULTS

Fifteen patients (6 women; Mage = 57 years; range 29-91 years) were enrolled into the study. Forty-six distinct lesions were identified in these 15 patients on (124)I PET/CT images, with a sensitivity of 92.5%. In addition, (124)I identified 22.5% more foci of RAI-avid lesions compared with the planar (131)I post-treatment scans. This study demonstrates different kinetic profiles for normal thyroid remnants (peaked at 24 h with mono-exponential clearance), salivary glands (peaked at 4 h with bi-exponential clearance), and metastatic lesions (protracted retention), as well as individual variations in functional volumes and thus cumulated activities.

CONCLUSIONS

(124)I PET/CT is a valuable clinical imaging tool/agent, both in determining the extent of disease in the setting of metastatic DTC and in the functional volumetric and kinetic evaluation of target lesions.

Value of post-therapeutic ¹³¹I scintigraphy in stimulated serum thyroglobulin-negative patients with metastatic differentiated thyroid carcinoma

Metastatic differentiated thyroid carcinoma (DTC) with positive (131)I scintigraphy, but negative stimulated Tg (sTg) is relatively rare in clinical practice. The clinical characteristics of these patients were analyzed in the current study. A total of 3367 consecutive histologically proven DTC patients were analyzed retrospectively from January 2007 to June 2013. Tg negativity was defined as a sTg level of <2 ng/mL without positive anti-Tg antibody (TgAb level of <100 IU/mL) under thyroid-stimulating hormone stimulation (TSH level of ≥30 mIU/L). Analyses were performed using the Statistical Package for the Social Sciences, version 20.0 (SPSS, Chicago, IL, USA). Seventy-one patients (median age 45 years, range 17-68 years) were post-therapeutic (131)I-SPECT/CT positive and sTg negative (PTP-TN) constituting 2.1 % of all patients. Of these 71 patients, 2 (2.8 %) had bone metastasis, 11 (15.5 %) had lung metastasis, and 59 (83.1 %) had lymph node metastasis. Fifty-six patients had cervical lymph node metastasis (cLNM), and US was positive in 15 patients (26.8 %), while negative in 41 patients (73.2 %). When compared to patients with concordant positive results for sTg and (131)I scintigraphy, US showed a relatively lower positive rate in the detection of cLNM in PTP-TN patients (28.8 vs. 53.8 %; χ (2) = 6.70; P = 0.01). In conclusion, even with sTg <2 ng/mL, there is a low risk of metastatic DTC. US had limitations in PTP-TN patients, while post-therapy (131)I-SPECT/CT demonstrated an advantage in the detection of functioning metastasis despite low sTg levels in patients with metastatic DTC.

Evaluating Positron Emission Tomography Use in Differentiated Thyroid Cancer

BACKGROUND

Using the Surveillance, Epidemiology, and End Results-Medicare database, a substantial increase was found in the use of positron emission tomography (PET) scans after 2004 in differentiated thyroid cancer (DTC) patients. The reason for the increased utilization of the PET scan was not clear based on available the data. Therefore, the indications for and outcomes of PET scans performed at an academic institution were evaluated.

METHODS

A retrospective cohort study was performed of DTC patients who underwent surgery at the University of Michigan Health System from 2006 to 2011. After identifying patients who underwent a PET scan, indications, rate of positive PET scans, and impact on management were evaluated. For positive scans, the location of disease was characterized, and presence of disease on other imaging was determined.

RESULTS

Of the 585 patients in the cohort, 111 (19%) patients had 200 PET scans performed for evaluation of DTC. Indications for PET scan included: elevated thyroglobulin and negative radioiodine scan in 52 scans (26.0%), thyroglobulin antibodies in 13 scans (6.5%), rising thyroglobulin in 18 scans (9.0%), evaluation of abnormality on other imaging in 22 scans (11.0%), evaluation of extent of disease in 33 scans (16.5%), follow-up of previous scan in 57 scans (28.5%), other indications in two scans (1.0%), and unclear indications in three scans (1.5%). The PET scan was positive in 124 studies (62.0%); positivity was identified in the thyroid bed on 25 scans, cervical or mediastinal lymph nodes on 105 scans, lung on 28 scans, bone on four scans, and other areas on 14 scans. Therapy following PET scan was surgery in 66 cases (33.0%), chemotherapy or radiation in 23 cases (11.5%), observation in 110 cases (55.0%), and palliative care in one case (0.5%). Disease was identifiable on other imaging in 66% of cases. PET scan results changed management in 59 cases (29.5%).

CONCLUSIONS

In this academic medical center, the PET scan was utilized in 19% of patients. Indications for the PET scan included conventional indications, such as elevated thyroglobulin with noniodine avid disease, and more controversial uses, such as evaluation of extent of disease or abnormalities on other imaging tests. PET scan results changed management in about 30% of cases.

Cost-effectiveness analysis of papillary thyroid cancer surveillance

BACKGROUND

The recent overdiagnosis of subclinical, low-risk papillary thyroid cancer (PTC) coincides with a growing national interest in cost-effective health care practices. The aim of this study was to measure the relative cost-effectiveness of disease surveillance of low-risk PTC patients versus intermediate- and high-risk patients in accordance with American Thyroid Association risk categories.

METHODS

Two thousand nine hundred thirty-two patients who underwent thyroidectomy for differentiated thyroid cancer between 2000 and 2010 were identified from the institutional database; 1845 patients were excluded because they had non-PTC cancer, underwent less than total thyroidectomy, had a secondary cancer, or had <36 months of follow-up. In total, 1087 were included for analysis. The numbers of postoperative blood tests, imaging scans and biopsies, clinician office visits, and recurrence events were recorded for the first 36 months of follow-up. Costs of surveillance were determined with the Physician Fee Schedule and Clinical Lab Fee Schedule of the Centers for Medicare and Medicaid Services.

RESULTS

The median age was 44 years (range, 7-83 years). In the first 36 months after thyroidectomy, there were 3, 44, and 22 recurrences (0.8%, 7.8%, and 13.4%) in the low-, intermediate-, and high-risk categories, respectively. The cost of surveillance for each recurrence detected was US $147,819, US $22,434, and US $20,680, respectively.

CONCLUSIONS

The cost to detect a recurrence in a low-risk patient is more than 6 and 7 times greater than the cost for intermediate- and high-risk PTC patients. It is difficult to justify this allocation of resources to the surveillance of low-risk patients. Surveillance strategies for the low-risk group should, therefore, be restructured.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed.

METHODS

A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force.

RESULTS

These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided.

CONCLUSIONS

In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.

The Effect of Diagnostic Absorbed Doses from 131I on Human Thyrocytes in Vitro

Background: Administration of diagnostic activities of ¹³¹I, performed in order to detect thyroid remnants after surgery and/or thyroid cancer recurrence/metastases, may lead to reduction of iodine uptake. This phenomenon is called “thyroid stunning”. We estimated radiation absorbed dose-dependent changes in genetic material, in particular in sodium iodide symporter (NIS) gene promoter, and NIS protein level in human thyrocytes (HT). Materials and Methods: We used unmodified HT isolated from patients subjected to thyroidectomy exposed to ¹³¹I in culture. The different ¹³¹I activities applied were calculated to result in absorbed doses of 5, 10, and 20 Gy. Results: According to flow cytometry analysis and comet assay, ¹³¹I did not influence the HT viability in culture. Temporary increase of 8-oxo-dG concentration in HT directly after 24 h (p < 0.05) and increase in the number of AP-sites 72 h after termination of exposition to 20 Gy dose (p < 0.0001) were observed. The signs of dose-dependent DNA damage were not associated with essential changes in the NIS expression on mRNA and protein levels. Conclusions: Our observation constitutes a first attempt to evaluate the effect of the absorbed dose of ¹³¹I on HT. The results have not confirmed the theory that the “thyroid stunning” reduces the NIS protein synthesis.

[Clinical guideline for management of patients with low risk differentiated thyroid carcinoma]

Incidence of thyroid cancer is increasing in Spain and worldwide. Overall thyroid cancer survival is very high, and stratification systems to reliably identify patients with worse prognosis have been developed. However, marked differences exist between the different specialists in clinical management of low-risk patients with thyroid carcinoma. Almost half of all papillary thyroid carcinomas are microcarcinomas, and 90% are tumors < 2 cm that have a particularly good prognosis. However, they are usually treated more aggressively than needed, despite the lack of adequate scientific support. Surgery remains the gold standard treatment for these tumors. However, lobectomy may be adequate in most patients, without the need for total thyroidectomy. Similarly, prophylactic lymph node dissection of the central compartment is not required in most cases. This more conservative approach prevents postoperative complications such as hypoparathyroidism or recurrent laryngeal nerve injury. Postoperative radioiodine remnant ablation and strict suppression of serum thyrotropin, although effective for the more aggressive forms of thyroid cancer, have not been shown to be beneficial for the treatment of low risk patients, and may impair their quality of life. This guideline provides recommendations from the task force on thyroid cancer of the Spanish Society of Endocrinology and Nutrition for adequate management of patients with low-risk thyroid cancer.

Relevance of BRAF(V600E) mutation testing versus RAS point mutations and RET/PTC rearrangements evaluation in the diagnosis of thyroid cancer

BACKGROUND

A molecular profile including BRAF and RAS mutations as well as RET/PTC rearrangement evaluation has been proposed to provide an accurate presurgical assessment of thyroid nodules and to reduce the number of unnecessary diagnostic surgeries, sparing patients' health and saving healthcare resources. However, the application of such molecular analyses may provide different results among different centers and populations in real-life settings. Our aims were to evaluate the diagnostic utility of assessing the presence of BRAF and RAS mutations and RET/PTC1 and RET/PTC3 rearrangements in all cytological categories in an Italian group of thyroid nodule patients assessed prospectively, and to understand whether and which mutation testing might be helpful in cytologically indeterminate nodules.

METHODS

A total of 911 patients were submitted to ultrasound and fine-needle aspiration biopsy examination. Cytological evaluation was performed in parallel with molecular testing and compared to pathological results in 940 thyroid nodules, including 140 indeterminate lesions.

RESULTS

BRAF mutation testing provided the best contribution to cancer diagnosis, allowing the disease to be detected at an early stage, and identifying indeterminate nodules in which diagnostic lobectomy could be spared. On the contrary, RAS and RET/PTC analysis did not further increase diagnostic sensitivity for thyroid cancer. In addition, we found RET/PTC rearrangements in benign lesions, indicating that this molecular marker might not be useful for the detection of thyroid cancer.

CONCLUSION

BRAF(V600E) mutation analysis is superior to RAS point mutations and evaluation of RET/PTC rearrangements in the diagnosis of thyroid cancer, even in indeterminate lesions.

Importance of postoperative stimulated thyroglobulin level at the time of 131I ablation therapy for differentiated thyroid cancer

BACKGROUND

Serum thyroglobulin detection plays an essential role during the follow-up of thyroid cancer patients treated with total/near total thyroidectomy and radioiodine ablation. The aim of this retrospective study was to evaluate the relationship between stimulated serum thyroglobulin (Tg) level at the time of high dose 131I ablation and risk of recurrence, using a three-level classification in patients with differentiated thyroid cancer (DTC) according to the ATA guidelines. Also we investigated the relationship between postoperative stimulated Tg at the time of ablation and DxWBS results at 8-10 months thereafter.

MATERIALS AND METHODS

Patients with radioiodine accumulation were regarded as scan positive (scan +). If there was no relevant pathological radioiodine accumulation or minimal local accumulation in the thyroid bed region, this were regarded as scan negative (scan-) at the time of DxWBS. We classified patients in 3 groups as low, intermediate and high risk group for assessment of risk of recurrence according to the revised ATA guidelines. Also, we divided patients into 3 groups based on the stimulated serum Tg levels at the time of 131I ablation therapy. Groups 1-3 consisted of patients who had Tg levels of ≤ 2 ng/ml, 2-10 ng/ml, and ≥ 10 ng/ml, respectively.

RESULTS

A total of 221 consecutive patients were included. In the high risk group according to the ATA guideline, while 45.5% of demonstrated Scan(+) Tg(+), 27.3% of patients demonstrated Scan(-) Tg(-); in the intermediate group, the figures were 2.3% and 90.0% while in the low risk group, they were 0.6% and 96.4%. In 9 of 11 patients with metastases (81.8%), stimulated serum Tg level at the time of radioiodine ablation therapy was over 10, however in 1 patient (9.1%) it was < 2 ng/mL and in one patient it was 2-10 ng/mL (p = 0.005). Aggressive subtypes of DTC were found in 8 of 221 patients and serum Tg levels were ≤ 2 ng/ml in 4 of these 8.

CONCLUSIONS

We conclude that TSH-stimulated serum thyroglobulin level at the time of ablation may not determine risk of recurrence. Therefore, DxWBS should be performed at 8-12 months after ablation therapy.

How sensitive (second-generation) thyroglobulin measurement is changing paradigms for monitoring patients with differentiated thyroid cancer, in the absence or presence of thyroglobulin autoantibodies

PURPOSE OF REVIEW

To discuss new insights regarding how sensitive (second-generation) thyroglobulin immunometric assays (TgIMAs), (functional sensitivities ≤0.10 μg/L) necessitate different approaches for postoperative thyroglobulin monitoring of patients with differentiated thyroid cancer (DTC), depending on the presence of thyroglobulin autoantibodies (TgAbs).

RECENT FINDINGS

Reliable low-range serum thyroglobulin measurement has both enhanced clinical utility and economic advantages, provided TgAb is absent (∼75% DTC patients). Basal [nonthyroid-stimulating hormone (TSH) stimulated] TgIMA measurement obviates the need for recombinant human TSH stimulation because basal TgIMA below 0.20 μg/L has comparable negative predictive value (>95%) to recombinant human TSH-stimulated thyroglobulin values below the cutoff of 2 μg/L. Now that radioiodine remnant ablation is no longer considered necessary to treat low-risk DTC, the trend and doubling time of low basal thyroglobulin values arising from postsurgical thyroid remnants have recognized prognostic significance. The major limitation of TgIMA testing is interference by TgAb (∼25% DTC patients), causing TgIMA underestimation that can mask disease. When TgAb is present, the trend in TgAb concentrations (measured by the same method) can serve as the primary (surrogate) tumor-marker and be augmented by thyroglobulin measured by a TgAb-resistant class of method (radioimmunoassay or liquid chromatography-tandem mass spectrometry).

SUMMARY

The growing use of TgIMA measurement is changing paradigms for postoperative DTC monitoring. When TgAb is absent, it is optimal to monitor the basal TgIMA trend and doubling time (using the same method) in preference to recombinant human TSH-stimulated thyroglobulin testing. When TgAb is present, interference renders TgIMA testing unreliable and the trend in serum TgAb concentrations per se (same method) can serve as a (surrogate) tumor-marker.

The advent of ultrasound-guided ablation techniques in nodular thyroid disease: towards a patient-tailored approach

Surgery is the long-established therapeutic option for benign thyroid nodules, which steadily grow and become symptomatic. The cost of thyroid surgery, the risk of temporary or permanent complications, and the effect on quality of life, however, remain relevant concerns. Therefore, various minimally invasive treatments, directed towards office-based management of symptomatic nodules, without requiring general anaesthesia, and with negligible damage to the skin and cervical tissues, have been proposed during the past two decades. Today, ultrasound-guided percutaneous ethanol injection and thermal ablation with laser or radiofrequency have been thoroughly evaluated, and are accessible procedures in specialized centres. In clinical practice, relapsing thyroid cysts are effectively managed with percutaneous ethanol injection treatment, which should be considered therapy of choice. In solid non-functioning thyroid nodules that grow or become symptomatic, trained operators may safely induce, with a single session of laser ablation treatment or radiofrequency ablation, a 50% volume decrease and, in parallel, improve local symptoms. In contrast, hyperfunctioning nodules remain best treated with radioactive iodine, which results in a better control of hyperthyroidism, also in the long-term, and fewer side-effects. Currently, minimally invasive treatment is also investigated for achieving local control of small size neck recurrences of papillary thyroid carcinoma in patients who are poor candidates for repeat cervical lymph node dissection. This particular use should still be considered experimental.

Low-risk papillary thyroid cancer: times are changing

The prevalence of papillary thyroid cancer (PTC), particularly of low-risk PTC (MACIS <6), is rising due to the increasingly use of neck imaging techniques, fine-needle aspiration and whole body PET scans. Observational cohort studies carried out in the last two decades suggest that low-risk PTC are being overtreated due to the current management paradigm being built on studies done in the 70s and 80s that still echo in some influential guidelines. With the progressive adoption of total thyroidectomy and central neck dissection as the mainstay of treatment for PTC, and suppressed basal thyroglobulin and neck ultrasound once a year as the essential tools for follow-up, the use of radioiodine ablation, body scans and stimulated thyroglobulin concentrations has become obsolete for the vast majority of patients with low-risk PTC. Future guidelines on the management of differentiated thyroid cancer should discuss separately three different diseases: low-risk PTC, high-risk PTC and follicular cancer.