Cost-effectiveness of fine-needle aspiration cytology (FNAC) and watchful observation for incidental thyroid nodules

Cost-Effectiveness of the ACR TIRADS Compared to the ATA 2015 Risk Stratification Systems in the Evaluation of Incidental Thyroid Nodules

RATIONALE AND OBJECTIVES

Thyroid nodules are a common incidental imaging finding and prone to overdiagnosis. Several risk stratification systems have been developed to reduce unnecessary work-up, with two of the most utilized including the American Thyroid Association 2015 (ATA2015) and the newer American College of Radiology Thyroid Imaging, Reporting and Data System (TIRADS) guidelines. The purpose of this study is to evaluate the cost-effectiveness of the ATA2015 versus the TIRADS guidelines in the management of incidental thyroid nodules.

METHODS

A cost-utility analysis was conducted using decision tree modeling, evaluating adult patients with incidental thyroid nodules < 4 cm. Model inputs were populated using published literature, observational data, and expert opinion. Single-payer perspective, Canadian dollar currency, five-year time horizon, willingness to pay (WTP) threshold of $50,000, and discount rate of 1.5% per annum were utilized. Scenario, deterministic and probabilistic sensitivity analyses were performed. The primary outcome was the incremental cost-effectiveness ratio (ICER) expressed as incremental cost per quality-adjusted life year (QALY) gained.

RESULTS

For the base case scenario, TIRADS dominated the ATA2015 strategy by a slim margin, producing 0.005 more QALYs at $25 less cost. Results were sensitive to the malignancy rate of biopsy and the utilities of a patient with a benign nodule/subclinical malignancy or under surveillance. Probabilistic sensitivity analysis showed that TIRADS was the more cost-effective option 79.7% of the time.

CONCLUSION

The TIRADS guidelines may be the more cost-effective strategy by a small margin compared to ATA2015 in most scenarios when used to risk stratify incidental thyroid nodules.

Telecytology rapid onsite evaluation, with real-time communication between cytopathologist, cytotechnologist, and proceduralist, offers better adequacy rates for lymph node, but not thyroid, fine-needle aspirations

INTRODUCTION

Rapid onsite evaluation (ROSE) decreases rates of inadequate fine-needle aspirations (FNAs). Telecytology allows pathologists to perform ROSE without being physically "on site", thereby saving cytopathologists' travel time and allowing them to perform ROSE for multiple institutions. Little research exists comparing telecytology to non-telecytology ROSE for FNA inadequacy rates.

MATERIALS AND METHODS

Using previously obtained quality metrics, we compared inadequacy rates for lymph node and thyroid FNAs with and without ROSE and with non-telecytology ROSE compared with telecytology ROSE. Use of ROSE was determined by the proceduralist. Type of ROSE was location-based, as only certain locations at our institution have telecytology capabilities. Chi-squared testing was used to compare proportions of populations and P value was set to 0.05.

RESULTS

A total of 1168 lymph node and 1177 thyroid FNAs were included in our adequacy analysis. We found any ROSE decreased our inadequacy rate for both lymph node (20.4% to 12.7%, P = 0.002) and thyroid (34.7% to 4.8%, P = 7.4 × 10-18) FNAs. We found telecytology further decreased our inadequacy rate for lymph node (13.8% to 5.9%, P = 0.016), but not thyroid (3.3% to 5.0%, P = 0.34), FNAs.

CONCLUSIONS

At our institution, when using telecytology, slides are read in real time with the cytotechnologist and the proceduralist looking at slides together near the patient bedside, while the cytopathologist is on the phone looking at slides on the computer screen via Dameware. When non-telecytology ROSE is performed, the cytotechnologist evaluates a slide, brings it to the cytopathologist's office and then the cytopathologist calls the proceduralist to discuss the slide. We believe telecytology offers an opportunity for more inclusive communication thereby improving adequacy rates for more complex cases, like lymph nodes, without affecting adequacy rates for cases where assessment of adequacy is less complex, like thyroid. This research supports use of telecytology especially for complex cases.

High-Suspicion Subcentimeter Thyroid Nodules: Cost Effectiveness of Active Surveillance versus Fine Needle Aspiration

PURPOSE

To compare the cost-benefit of active surveillance (AS) against immediate fine needle aspiration (FNA) of sonographically suspicious subcentimeter thyroid nodules.

MATERIALS AND METHODS

A Markov model was constructed to compare the cost-benefit of 3 strategies from the point of discovery until death: (a) Surveillance of all nodules, (b) Surveillance of nodules with positive cytology, and (c) Surgery of nodules with positive cytology. The reference case was a 40-year-old woman with a sonographically suspicious subcentimeter thyroid nodule. Transition probabilities, costs, and health state utilities were derived from the literature. Sensitivity analyses were performed to evaluate model uncertainty. Willingness-to-pay threshold was set at $100,000/quality-adjusted life year.

RESULTS

Surveillance of nodules with positive cytology dominated in the reference scenario and was cost-beneficial over Surveillance of all nodules, independent of the utility of AS. Surveillance of all nodules was cost-beneficial only at a life expectancy of <2.6 years or surveillance duration of <4 years.

CONCLUSIONS

While current guidelines recommend AS of sonographically suspicious subcentimeter nodules, the results of this study suggest that immediate FNA (Surveillance of nodules with positive cytology) is more cost-beneficial than AS (Surveillance of all nodules). Patients with positive cytology on FNA may subsequently opt for AS (Surveillance of nodules with positive cytology) or surgery (Surgery of nodules with positive cytology) according to their level of comfort (ie, utility) with AS.

Comparison of fine-needle aspiration with fine-needle capillary cytology in thyroid nodules

INTRODUCTION

High false-negative results have been reported for fine-needle aspiration (FNA) cytology in thyroid nodules. Fine-needle capillary (FNC) cytology is an alternative technique that prevents aspiration, reducing tissue damage. This study aimed to compare FNA and FNC in assessing thyroid nodules and in terms of their predictive role in the appropriate diagnosis of malignancy.

METHODS

This is a comparative prospective study conducted on 486 patients. FNA was performed in 235 patients during 2016 and 2017 and FNC in 251 patients during 2018 and 2019. The quality of cytological specimens was compared and then correlated with the final histopathological findings of 39 patients who underwent thyroidectomy.

RESULTS

Both groups were statistically similar regarding age and sex distribution. The FNA technique yielded significantly higher adequate specimens compared with FNC (p<0.001). Abundant blood in the background was found more frequently in the FNA technique (p<0.001). The sensitivity and specificity of FNA for malignancy diagnosis were both 100%, compared with 83.3% and 57.7% for FNC, respectively.

CONCLUSIONS

The two methods, FNA and FNC, did not differ in terms of overall quality. FNA was superior regarding consistency with the histopathological results and the ability to diagnose malignancy.

Thyroid nodules: Global, economic, and personal burdens

Thyroid nodules have garnered attention due to changes in population surveillance systems and rising concerns about the associated financial burden on healthcare systems, payers, and patients. In this review, we find that prevalence rates vary widely based on method of detection and may particularly pronounced in asymptomatic patients undergoing routine screening. Incidence rates may be particularly rising in lower-income and middle-income countries and may be declining in higher-income countries. Despite high incidence rates, survival rates continue to be as high as 97% for papillary thyroid cancer. Over the last few decades, thyroid nodule workup and management has grown more sophisticated with the advent of fine-needle aspiration biopsy, specialized biomarkers, and molecular testing. However, gaps remain in risk stratification that can lead to substantial costs of care. Certain molecular tests, such as the Afirma Gene Sequencing Classifier can lead to a cost per diagnosis of $17,873 while achieving only mild decreases in diagnostic lobectomies for patients (11.6% to 9.7% in one study). Out-of-pocket costs associated with thyroid nodule management continue to drive significant financial toxicity for patients, especially for individuals with thyroid cancer. Financial toxicity has been defined as a term that describes how direct and indirect medical costs of cancer care strain patients and households via decreased income, assets, and spending on basic necessities. Recent studies suggest that such toxicity can lead to adverse financial outcomes, such as foreclosure and bankruptcy. Additional cost-effectiveness analyses are needed to improve existing thyroid nodule management systems and new clinical tools are needed to avoid unnecessary workup and management.

The prevalence and associated predictors for Bethesda III-VI for reporting thyroid cytopathology in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND

Thyroid cancer is increasing globally and is currently the most prevalent endocrine malignancy. Recent data show an increase in the incidence of thyroid cancer in the Kingdom of Saudi Arabia (KSA). Thyroid ultrasound and fine-needle aspiration cytology (FNAC) are the cornerstones in managing thyroid nodules. We conducted this study to evaluate the prevalence and the associated predictors for thyroid nodule Bethesda III-VI in eastern KSA.

METHODS

A retrospective study was conducted between January 2015 and 31 August 2021. The participants were recruited patients who received a thyroid ultrasound and ultrasound-guided thyroid FNAC, using the thyroid imaging reporting and data system (TI-RADS) and the Bethesda Classification, respectively.

RESULT

Three hundred and ten patients who underwent thyroid FNAC were enrolled in the study. The median (interquartile, IQR) age was 47.0 (20.0) years, and 266 (85.8%) of them were females. The median (IQR) body mass index was 30.2 (7.6) kg/m². Out of these participants, 64.8% were euthyroid, 27.4% had hypothyroidism and 7.7% had hyperthyroidism. The ACR TI-RADS-3, 4 and 5 were 51.3%, 46.1% and 2.6%, respectively. The Bethesda outcome of thyroid FNAC I-VI was 5.2%, 63.9%, 15.5%, 5.8%, 3.5% and 6.1%, respectively. The risk for malignancy (Bethesda III-VI) was documented in 31.0% and atypia of undetermined significance was most prevalent (15.5%). A higher ACR TI-RADS score was associated with a higher risk of malignancy: ACR TI-RADS-3 (20.8%), ACR TI-RADS-4 (39.2%) and ACR TI-RADS-5 (87.5%). In a multivariate analysis, only the ACR TI-RADS score was significantly associated with the outcome of thyroid FNAC: ACR TI-RADS-4 [OR = 2.59 (95% CI = 1.54-4.36)] and ACR TI-RADS-5 [OR = 29.03 (95% CI = 3.44-245.07)].

CONCLUSION

There was a high prevalence of Bethesda III-VI and atypia of undetermined significance was most prevalent. A thyroid ultrasound report for TI-RADS was significantly associated with the outcome of thyroid FNAC and is a reliable tool in the absence of molecular testing for thyroid cancer.

Association of the Implementation of a Standardized Thyroid Ultrasonography Reporting Program With Documentation of Nodule Characteristics

Importance

Although most thyroid nodules are benign, the potential for malignant neoplasms is associated with unnecessary workup in the form of imaging, fine-needle aspiration, and diagnostic surgery. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is commonly used to assess the malignant neoplasm risk potential of thyroid nodules imaged by ultrasonography. However, standardized reporting of ACR TI-RADS descriptors is inconsistent.

Objective

To increase the documentation rate of ACR TI-RADS thyroid nodule characteristics to 80% in 18 months.

Design, Setting, and Participants

This prospective interrupted time series quality improvement study was conducted from December 1, 2018, to March 31, 2020, at a tertiary outpatient head and neck clinic among 229 patients who had at least 1 documented thyroid nodule identified on bedside clinic ultrasonography. Data analysis was performed throughout the entire study period because this was a quality improvement study with iterative small cycle changes; final analysis of the data was performed in April 2020.

Main Outcomes and Measures

The primary outcome was the documentation rates of 6 ACR TI-RADS ultrasonographic descriptors. Secondary outcomes included nodule fine-needle aspiration biopsy rate and physician-reported clinic flow efficiency.

Results

A total of 229 patients had at least 1 documented thyroid nodule and were included in the analysis. Size was the most frequently documented nodule characteristic (72 of 74 [97.3%]) at baseline, followed by echogenic foci (31 of 74 [41.9%]), composition (23 of 74 [31.1%]), echogenicity (17 of 74 [23.0%]), margin (6 of 74 [8.1%]), and shape (1 of 74 [1.4%]). After 3 Plan, Do, Study, Act (PDSA) cycles, the final intervention consisted of a standardized ultrasonography reporting form and educational initiatives for surgical trainees. After the third PDSA cycle (n = 36), reporting of nodule size, echogenic foci, and composition increased to 100%. Similarly, reporting of echogenicity (34 of 36 [94.4%]), shape (28 of 36 [77.8%]), and margin (25 of 36 [69.4%]) all increased. This represented a cumulative 90.3% documentation rate (195 of 216), a 56.5% increase from baseline (95% CI, 50.0%-61.9%). The standardized reporting form was used in 83.3% of eligible thyroid ultrasonography cases (30 of 36) after PDSA cycle 3, demonstrating good fidelity of implementation. There were no unintended consequences associated with clinic workflow, as a balancing measure, reported by staff surgeons.

Conclusions and Relevance

This study suggests that implementation of an ACR TI-RADS-based reporting form in conjunction with educational initiatives improved documentation of ultrasonographic thyroid nodule characteristics, potentially allowing for improved bedside risk stratification and communication among clinicians.

Malignant and benign thyroid nodule differentiation through the analysis of blood plasma with terahertz spectroscopy

The liquid and lyophilized blood plasma of patients with benign or malignant thyroid nodules and healthy individuals were studied by terahertz (THz) time-domain spectroscopy and machine learning. The blood plasma samples from malignant nodule patients were shown to have higher absorption. The glucose concentration and miRNA-146b level were correlated with the sample's absorption at 1 THz. A two-stage ensemble algorithm was proposed for the THz spectra analysis. The first stage was based on the Support Vector Machine with a linear kernel to separate healthy and thyroid nodule participants. The second stage included additional data preprocessing by Ornstein-Uhlenbeck kernel Principal Component Analysis to separate benign and malignant thyroid nodule participants. Thus, the distinction of malignant and benign thyroid nodule patients through their lyophilized blood plasma analysis by terahertz time-domain spectroscopy and machine learning was demonstrated.

The Role of Exosomes in Thyroid Cancer and Their Potential Clinical Application

The incidence of thyroid cancer (TC) is rapidly increasing worldwide. The diagnostic accuracy and dynamics of TC need to be improved, and traditional treatments are not effective enough for patients with poorly differentiated thyroid cancer. Exosomes are membrane vesicles secreted specifically by various cells and are involved in intercellular communication. Recent studies have shown that exosomes secreted by TC cells contribute to tumor progression, angiogenesis and metastasis. Exosomes in liquid biopsies can reflect the overall molecular information of tumors, and have natural advantages in diagnosing TC. Exosomes also play an important role in tumor therapy due to their special physicochemical properties. TC patients will benefit as more exosome patterns are discovered. In this review, we discuss the role of TC-derived exosomes in tumorigenesis and development, and describe the application of exosomes in the diagnosis and treatment of TC.

Early Diagnosis of Low-Risk Papillary Thyroid Cancer Results Rather in Overtreatment Than a Better Survival

We are witnessing a rapid worldwide increase in the incidence of papillary thyroid carcinoma (PTC) in the last thirty years. Extensive implementation of cancer screening and wide availability of neck ultrasound or other imaging studies is the main reason responsible for this phenomenon. It resulted in a detection of a growing number of clinically asymptomatic PTCs, mainly low-risk tumors, without any beneficial impact on survival. An indolent nature of low-risk PTC, particularly papillary thyroid microcarcinoma (PTMC), and the excellent outcomes raise an ongoing discussion regarding the adequacy of treatment applied. The question of whether PTMC is overtreated or not is currently completed by another, whether PTMC requires any treatment. Current ATA guidelines propose less extensive preoperative diagnostics and, if differentiated thyroid cancer is diagnosed, less aggressive surgical approach and limit indications for postoperative radioiodine therapy. However, in intrathyroidal PTMCs in the absence of lymph node or distant metastases, active surveillance may constitute alternative management with a low progression rate of 1%-5% and without any increase in the risk of poorer outcomes related to delayed surgery in patients, in whom it was necessary. This review summarizes the current knowledge and future perspectives of active surveillance in low-risk PTC.