Thyroid nodule ultrasound reports in routine clinical practice provide insufficient information to estimate risk of malignancy

Clinical value of molecular markers as diagnostic and prognostic tools to guide treatment of thyroid cancer

OBJECTIVE

Advances in our understanding of the molecular biology of thyroid tumours is being rapidly translated into their clinical management. This review summarizes the current use of molecular testing in thyroid tumours, focusing on their usefulness as diagnostic and prognostic tools to guide treatment with consideration of present limitations.

DESIGN

Considerations about molecular testing applications for the diagnosis and treatment of thyroid tumours are divided into four sections/roles: (1) evaluating cytologically indeterminate thyroid nodules; (2) guiding extent of surgery in indeterminate thyroid nodules; (3) completing histological characterization of thyroid tumours and (4) identifying actionable mutations in advanced progressive thyroid cancers.

RESULTS

Genomic testing can improve the presurgical malignancy risk assessment in indeterminate thyroid nodules. However, a prior in-depth analysis of institutional quality and outcomes of sonographical, cytological and histological characterization of thyroid tumours is necessary. Presently, it remains uncertain whether knowing the molecular profile of a cytologically indeterminate thyroid nodule might be advantageous to modify the extent of initial surgery. Molecular characterization of thyroid tumours can be a valuable adjunct to morphological diagnosis in some challenging cases, such as in low-risk follicular cell-derived neoplasms, or rare tumours. Finally, as selective kinase inhibitors are available, molecular testing in locally advanced/metastatic progressive thyroid cancers should also be integrated into the institutional clinical management pathway to improve outcomes and limit toxicity.

CONCLUSIONS

Molecular testing needs to be implemented into the local evidence-based clinical management thyroid nodule/cancer pathways to improve its diagnostic and prognostic value and to optimize cost-effectiveness.

DIAGNOSIS OF ENDOCRINE DISEASE: Usefulness of genetic testing of fine-needle aspirations for diagnosis of thyroid cancer

OBJECTIVE

Genetic testing is increasingly used to diagnose or rule out thyroid cancer in indeterminate fine-needle aspirations. This review evaluates the usefulness of these methods with considerations of advantages and limitations.

DESIGN

Given the diagnostic problem associated with the increasing incidental detection of indeterminate thyroid nodules in the context of thyroid cancer overtreatment, we consider the conditions and respective necessary settings for the role of genetic testing to improve presurgical malignancy risk stratification.

METHODS

We review diagnostic pathway requirements and commercially available molecular tests with their respective advantages and disadvantages and discuss the prerequisites required for local application and implementation including quality assurance for local ultrasound and cytopathology practices.

RESULTS

Recent improvements in available molecular diagnostic tests have brought high sensitivity and specificity in initial validation studies, but whether these promising results translate to other clinical settings depends on the quality of the local thyroid nodule diagnostic pathway.

CONCLUSIONS

Genetic testing can meaningfully improve presurgical malignancy risk assessment, but more work is needed to implement and use genetic testing effectively in local settings.

Improvement in thyroid ultrasound report quality with radiologists' adherence to 2015 ATA or 2017 TIRADS: a population study

Objectives

There has been slow adoption of thyroid ultrasound guidelines with adherence rates as low as 30% and no population-based studies investigating adherence to guideline-based malignancy risk assessment. We therefore evaluated the impact of adherence to the 2015 ATA guidelines or 2017 ACR-TIRADS guidelines on the quality of thyroid ultrasound reports in our healthcare region.

Methods

We reviewed 899 thyroid ultrasound reports of patients who received fine-needle aspiration biopsy and were diagnosed with Bethesda III or IV nodules or thyroid cancer. Ultrasounds were reported by radiology group 1, group 2, or other groups, and were divided into pre-2018 (before guideline adherence) or 2018 onwards. Reports were given a utility score (0-6) based on how many relevant nodule characteristics were included.

Results

Group 1 had a pre-2018 utility score of 3.62 and 39.4% classification reporting rate, improving to 5.77 and 97.0% among 2018-onwards reports. Group 2 had a pre-2018 score of 2.8 and reporting rate of 11.5%, improving to 5.58 and 93.3%. Other radiology groups had a pre-2018 score of 2.49 and reporting rate of 32.2%, improving to 3.28 and 61.8%. Groups 1 and 2 had significantly higher utility scores and reporting rates in their 2018-onward reports when compared to other groups' 2018-onward reports, pre-2018 group 1 reports, and pre-2018 group 2 reports.

Conclusions

Dedicated adherence to published thyroid ultrasound reporting guidelines can lead to improvements in report quality. This will reduce diagnostic ambiguity and improve clinician's decision-making, leading to overall reductions in unnecessary FNA biopsy and diagnostic surgery.

Malignancy risk of thyroid nodules: quality assessment of the thyroid ultrasound report

Background

Thyroid nodules are a challenge in clinical practice and thyroid ultrasonography is essential for assessing the risk of malignancy. The use of ultrasound-based malignancy risk classification systems has been recommended by several scientific societies but radiologist’s adherence to these guidelines may vary. The authors aimed to analyze the quality of the information provided by the thyroid ultrasound report, to assess the malignancy risk of thyroid nodules, in Portugal.

Methods

Multicenter and retrospective study, conducted in three of the five Portuguese NUTS2 corresponding to about 88.3% of the mainland population. We included 344 consecutive unselected participants aged ≥ 18 years who underwent thyroid ultrasonography in 2019. The description of six features of the dominant thyroid nodule was analyzed: maximum size, shape, margins, composition, echogenicity and echogenic foci. A utility score, including these six features, was used as an indicator of the report’s quality. A score of 4 was considered as a minimum value.

Results

Maximum diameter was reported for all nodules. Shape, margins, composition, echogenicity and echogenic foci were reported in 8.1%, 25.0%, 76.5%, 53.2% and 20.9%, respectively. Only 21.8% of the nodules had a score ≥ 4. At least one of four suspicious features, including marked hypoechogenicity, microcalcifications, irregular margins and non-oval shape, was identified in 8.7% of the nodules. Cervical lymph nodes’ status was reported in 93% of the exams. The risk category was only reported in 7.8% of the participants.

Conclusion

The adherence of Portuguese radiologists to a standardized reporting model and to an ultrasound-based malignancy risk stratification system is still low and has implications for the correct characterization of the malignancy risk of nodules and the decision to perform fine-needle aspiration biopsy.

Outcomes of the Bethesda system for reporting thyroid cytopathology in community- vs. institution-performed cytology

OBJECTIVES

Despite the important role of the community in the assessment and risk stratification of patients with thyroid nodules, evidence-based data on the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) performance in community clinics is lacking. We aim to evaluate BSRTC performance of aspirations taken in community clinics compared with primary referral center.

METHODS

Patients who underwent thyroid surgery between 2013 and 2018 at our institution were divided according to the fine needle aspirations (FNA) settings: community FNA (cFNA) vs. institutional FNA (iFNA). Demographics, BSRTC results and final pathology were collected. Diagnostic values were calculated for BSRTC categories (sensitivity, specificity, positive predictive value [PPV], and negative predictive value [NPV]), and were compared between the groups.

RESULTS

A total of 268 nodules were included in the study; 77% (207) cFNA and 23% (61) iFNA. Patients in the community were younger (51.7 ± 15.1 vs. 56.6 years±14.8, p = 0.03) and with less epidemiology risk factors for thyroid cancer (1.9% vs 13.1%, p < 0.001). cFNA malignancy rate for BSRTC I-VI was 0%, 6.4%, 11.8%, 32.1%, 91.6% and 93.8% respectively. Best sensitivity was found for BSRTC III-VI in both groups (88% and 83%, cFNAs and iFNAs, respectively). Overall best performance was obtained for BSRTC V-VI for both groups (cfNA: 85%, 97%, 93%, 94% and 93%; iFNAs: 81%, 100%, 100%, 87% and 91%, for sensitivity, specificity, PPV, NPV and accuracy, respectively).

CONCLUSIONS

Community-performed FNAs demonstrate acceptable BSRTC distribution and malignancy rates, comparable with a primary referral academic hospital. This supports the universality of the BSRTC 2017 and its recommendations also in the community.

Accuracy of Thyroid Fine-Needle Aspiration Cytology: A Cyto-Histologic Correlation Study in an Integrated Canadian Health Care Region with Centralized Pathology Service

INTRODUCTION

The reported ROM within TBSRTC categories varies widely and depends on several factors in the clinical care pathway for thyroid nodules, including sonographic risk stratification, cytology expertise, selection criteria for surgical resection, and definitions of malignancy used.

METHODS

We present 5,867 consecutive thyroid FNAC and corresponding surgical pathology in the context of a comprehensive, single-payer health care system with centralized cytology and surgical pathology services for over 1.5 million inhabitants.

RESULTS

We report higher usage of ND and AUS/FLUS categories than the literature (19% vs. <10% and 15% vs. <10%, respectively). Our surgical resection rate for malignant cytology is substantially higher than the literature (94% vs. 50%, respectively). The ROM by the TBSRTC category in our cohort was similar to the literature. The overall diagnostic accuracy of thyroid FNAC was 92%, which is similar to other studies. Inclusion of incidental PMC as histologically malignant raised the ROM in the ND, benign, and AUS/FLUS categories.

DISCUSSION

The diagnostic performance of thyroid FNAC in our study is similar to the reported literature. Differences in TBSRTC category usage likely arise from cytologist variability and expertise. Our higher surgical resection rate in the malignant cytology category reflects the greater capture of surgical follow-up within our healthcare region with centralized pathology and a single EMR system. Keeping in mind the method of calculation of ROM, the malignancy rate by TBSRTC is similar to previous reports.

Impact of high-quality ultrasound following community ultrasound on surgical planning and active surveillance in patients with thyroid cancer

OBJECTIVE

Ultrasound (US) has gained a critical role in thyroid cancer treatment planning, yet it is limited by its user-dependent nature. The aim of this study was to compare the impact of US performed by radiologists specializing in thyroid imaging (hqUS) and US performed by radiographers in the community (cUS) on treatment plans of patients diagnosed with well-differentiated thyroid malignancies.

DESIGN

Retrospective single-centre case series with chart review.

PATIENTS

Patients diagnosed with thyroid cancer during 2017-2019 that had cUS followed by hqUS pre-operative counselling were included in this retrospective analysis.

MEASUREMENTS

The main outcome was management alternations based on one of two sonographic measures: (1) extrathyroid extension (ETE); (2) The presence of central or lateral lymph nodes suspicious for metastases (LNM), which were compared with the final pathology.

RESULTS

Among those with non-recurrent tumour (n = 76), ETE was reported 22 times more by hqUS compared with cUS (28.9% vs 1.3%, P < .001). Central and lateral LNM were reported approximately 6.5 and 1.5 times more by hqUS, respectively (25.0% vs 3.9%, P < .001 and 15.8% vs., 9.2%, P = .227, respectively). Overall, hqUS altered the initial treatment plan of 35.5% of patients. In 27.6% of patients, hqUS and its subsequent surgery resulted in a change to the patients' 2015 ATA risk stratification system. In 40% of patients with microcarcinomas, hqUS findings mandated surgery according to findings that were not reported by cUS. False-positive rate was 5.2%.

CONCLUSIONS

Community US may under-diagnose important features such as ETE and LNM, leading to potential under-treatment in many patients. High-quality US of the neck should be considered in patients with differentiated thyroid carcinoma before making any treatment decisions.

Outcomes of the Bethesda system for reporting thyroid cytopathology: Real-life experience

OBJECTIVE

The 2017 revised Bethesda System for Reporting Thyroid Cytopathology (BSRTC) included new malignancy rates for each category as well as new management recommendations. Here, we evaluate the malignancy rate and test performance for BSRTC categories in a middle-sized institution outside the United States (US).

DESIGN

Retrospective single centre case series with chart review.

PATIENTS

All patients who underwent thyroid surgery with a preoperative BSRTC between the years 2010 and 2018 at our institution.

MEASUREMENTS

In order to assess the malignancy rate for each BSRTC, all medical records were reviewed to collect demographics, nodule's size, BSRTC and final pathology.

RESULTS

Three hundred and sixty-four patients were included, with an overall malignancy rate of 34.3%. The malignancy rate for BSRTC categories I-VI was as follows: 13.3%, 5.1%, 25.0%, 24.4%, 91.3% and 95.2%, respectively. The most sensitive test was when BSRTC III-VI were evaluated (91%). Overall best performance (sensitivity, specificity, PPV, NPV and accuracy) was obtained when BSRTC V-VI were grouped together with a substantial decrease when adding BSRTC III-IV (90%, 97%, 94%, 95%, 95% vs, respectively, 91%, 73%, 62%, 95%, 79%, respectively).

CONCLUSIONS

Despite differences from the reported 2017 BSRTC malignancy rates, we demonstrated that the revised 2017 BSRTC management recommendations for thyroid nodules are also valid in smaller non-US centre, supporting its use globally.

Thyroid Ultrasound Reports: Will the Thyroid Imaging, Reporting, and Data System Improve Natural Language Processing Capture of Critical Thyroid Nodule Features?

BACKGROUND

Critical thyroid nodule features are contained in unstructured ultrasound (US) reports. The Thyroid Imaging, Reporting, and Data System (TI-RADS) uses five key features to risk stratify nodules and recommend appropriate intervention. This study aims to analyze the quality of US reporting and the potential benefit of Natural Language Processing (NLP) systems in efficiently capturing TI-RADS features from text reports.

MATERIALS AND METHOD

This retrospective study used free-text thyroid US reports from an academic center (A) and community hospital (B). Physicians created "gold standard" annotations by manually extracting TI-RADS features and clinical recommendations from reports to determine how often they were included. Similar annotations were created using an automated NLP system and compared with the gold standard.

RESULTS

Two hundred eighty-two reports contained 409 nodules at least 1-cm in maximum diameter. The gold standard identified three nodules (0.7%) which contained enough information to calculate a complete TI-RADS score. Shape was described most often (92.7% of nodules), whereas margins were described least often (11%). A median number of two TI-RADS features are reported per nodule. The NLP system was significantly less accurate than the gold standard in capturing echogenicity (27.5%) and margins (58.9%). One hundred eight nodule reports (26.4%) included clinical management recommendations, which were included more often at site A than B (33.9 versus 17%, P < 0.05).

CONCLUSIONS

These results suggest a gap between current US reporting styles and those needed to implement TI-RADS and achieve NLP accuracy. Synoptic reporting should prompt more complete thyroid US reporting, improved recommendations for intervention, and better NLP performance.

Contemporary Thyroid Nodule Evaluation and Management

CONTEXT

Approximately 60% of adults harbor 1 or more thyroid nodules. The possibility of cancer is the overriding concern, but only about 5% prove to be malignant. The widespread use of diagnostic imaging and improved access to health care favor the discovery of small, subclinical nodules and small papillary cancers. Overdiagnosis and overtreatment is associated with potentially excessive costs and nonnegligible morbidity for patients.

EVIDENCE ACQUISITION

We conducted a PubMed search for the recent English-language articles dealing with thyroid nodule management.

EVIDENCE SYNTHESIS

The initial assessment includes an evaluation of clinical risk factors and sonographic examination of the neck. Sonographic risk-stratification systems (e.g., Thyroid Imaging Reporting and Data Systems) can be used to estimate the risk of malignancy and the need for biopsy based on nodule features and size. When cytology findings are indeterminate, molecular analysis of the aspirate may obviate the need for diagnostic surgery. Many nodules will not require biopsy. These nodules and those that are cytologically benign can be managed with long-term follow-up alone. If malignancy is suspected, options include surgery (increasingly less extensive), active surveillance or, in selected cases, minimally invasive techniques.

CONCLUSION

Thyroid nodule evaluation is no longer a 1-size-fits-all proposition. For most nodules, the likelihood of malignancy can be confidently estimated without resorting to cytology or molecular testing, and low-frequency surveillance is sufficient for most patients. When there are multiple options for diagnosis and/or treatment, they should be discussed with patients as frankly as possible to identify an approach that best meets their needs.

American College of Radiology Thyroid Imaging Reporting and Data System standardises reporting of thyroid ultrasounds

Background

Thyroid nodules are common, the majority benign. The small risk of malignancy leads to excessive workup. Thyroid ultrasound is essential for risk stratification and management guidance. Without an organised reporting guideline, reports do not add significant value to referring clinicians. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) was developed to aid ultrasound reporting, lessen excessive biopsies and diagnose thyroid cancers.

Objectives

To standardise reporting of thyroid ultrasounds by utilising an organised reporting guideline based on ACR TI-RADS.

Method

Thyroid ultrasound reports generated by radiology registrars at an academic hospital were studied in two phases. In Phase 1, the reports were generated as free text, and in Phase 2, using a guideline based on ACR TI-RADS. The percentages of reports that described the maximum size, the five ACR TI-RADS features and a management recommendation were compared.

Results

A total of 130 reports were studied. Significant improvement was observed in the description of all five ACR TI-RADS categories (p < 0.0001) from Phase 1 to Phase 2. Of all the reports, 89% included a management recommendation. Reports including an ACR TI-RADS-based recommendation increased from 48% to 75% (p < 0.05). Recommendation for biopsy increased from 35.4% to 53.8% (p < 0.05).

Conclusion

Introduction of an organised reporting guideline based on ACR TI-RADS, standardised reporting of thyroid ultrasounds by increasing description of thyroid nodule features and ensuring appropriate management recommendations. This, in future, will prevent underdiagnosis of thyroid cancer and unnecessary workup of benign nodules.

Incomplete Thyroid Ultrasound Reports for Patients With Thyroid Nodules: Implications Regarding Risk Assessment and Management

OBJECTIVE

The purpose of this study was to determine the completeness of thyroid ultrasound (US) reports, assess for differences in report interpretation by clinicians, and evaluate for implications in patient care.

MATERIALS AND METHODS

We retrospectively reviewed thyroid US examinations performed between January and June 2013 in Nova Scotia, Canada. Baseline examinations that identified a nodule were evaluated for 10 reporting elements. Reports that lacked a comment regarding malignancy risk or a recommendation for biopsy were considered unclassified and were graded by three clinical specialists in accordance with the 2015 American Thyroid Association management guidelines. Interrater agreement was assessed using the Cohen kappa statistic. A radiologist reviewed the images of unclassified nodules, and on the basis of radiologic grading, biopsy rates and pathologic findings were compared between nodules that did and did not warrant biopsy.

RESULTS

Of 971 first-time thyroid US studies, 478 detected a nodule. The number of reports lacking a comment on the 10 elements ranged from 154 to 433 (32-91%). A total of 222 nodules (46%) were unclassified, and agreement in assigned grading by the clinical specialists was very poor (κ = 0.07; p < 0.05). According to radiologist grading, only 57 of 127 biopsies were performed on nodules that warranted biopsy, and 16 of 95 biopsies were performed unnecessarily. On the basis of the three clinical specialists' interpretation, 10, 31, and 33 reports were considered too incomplete to assign a grade; 40, 10, and four biopsies would have been unnecessarily ordered; and zero, three, and four cancers would have been missed.

CONCLUSION

There is widespread underreporting of established elements in thyroid US reports, and this causes confusion and discrepancy among clinical specialists regarding the risk of malignancy and the need for biopsy.