Fine Needle Aspiration Of Thyroid Nodules Research Articles

The Landmark Series: Testing in Thyroid Nodule Fine Needle Aspiration Cytology

The Landmark Series: Testing in Thyroid Nodule Fine Needle Aspiration Cytology

Performance of Afirma Genomic Sequencing Classifier in Binary Subcategories of Atypia of Undetermined Significance Thyroid Nodules: Single Versus Repeat Diagnosis.

Background: Afirma Genomic Sequencing Classifier (GSC) testing has been utilized for further risk stratification of thyroid nodules categorized as atypia of undetermined significance (AUS). The 2023 Bethesda system subcategorizes AUS diagnosis into AUS with nuclear atypia (AUS-N) and other atypia (AUS-O). The current study aims to determine if performance of GSC testing differs between the two AUS subcategories and between single AUS cohort and repeat AUS cohort. Methods: This retrospective study analyzed consecutive thyroid nodule fine-needle aspiration with a single or a repeat AUS diagnosis and a diagnostic GSC testing result (benign vs. suspicious). All AUS nodules were divided into AUS-N or AUS-O subcategory and followed by either surgical intervention or at least 12 months of clinical and/or ultrasound monitoring. We then assessed performance of GSC testing in each subcategory and subsequently compared the individual performance in AUS-N or AUS-O subcategory between single AUS cohort and repeat AUS cohort. Results: The study identified a total of 365 thyroid nodules subcategorized as AUS-N (N = 106) and AUS-O (N = 259). Both cohorts showed a significantly lower GSC benign call rate (BCR) in AUS-N nodules compared with AUS-O nodules (43% vs. 71% in single AUS, p = 0.001; 58% vs. 74% in repeat AUS, p = 0.02). The proportion of histology-proven malignancies associated with a suspicious GSC result tended to be greater in AUS-N nodules than AUS-O nodules (28% vs. 10% in single AUS, p = 0.09; 38% vs. 27% in repeat AUS, p = 0.3). Compared with AUS-N nodules, AUS-O cohorts demonstrated significantly higher specificity in the single AUS group (73% vs. 51%, p = 0.01). In both subcategories, the repeat AUS cohort yielded greater specificity, positive predictive value, and diagnostic accuracy compared with the single AUS group. However, the differences did not reach statistical significance. Conclusions: GSC BCR and diagnostic performance of GSC testing may vary in AUS-N versus AUS-O subcategories. However, there were no statistically significant differences in GSC performance between single and repeat AUS cohorts.

Diagnostic Accuracy of Bethesda Classification of Thyroid Nodules at a Kenyan Hospital: A Retrospective Study

Background: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was developed to standardize the reporting of thyroid nodule fine-needle aspiration cytology (FNAC) results. The adoption of TBSRTC is based on the implied risk of malignancy per category, but this has shown wide variation in different regions worldwide. Aim: The aim of this study is to determine the diagnostic accuracy of the Bethesda classification of thyroid nodules in a Kenyan hospital. Methods: A retrospective longitudinal study examined FNAC and histopathology data of thyroid gland nodules at a Kenyan hospital from 2010 to 2019; specimens from 347 patients were found. An analysis was performed to determine the diagnostic accuracy of the Bethesda classification in detecting malignancy among these patients. Results: The malignancy rate was 16.1%. The risk of malignancy as per the Bethesda category was as follows: non-diagnostic— 19.6%, benign—6%, atypia of undetermined significance—20%, follicular neoplasm—16.7%, suspicious for malignancy—80%, and malignant—85.7%. The diagnostic properties of FNAC defining “malignant” and “suspicious for malignancy” categories as malignant were as follows: sensitivity—64.7%, specificity—97.6%, and accuracy—92.7%. Conclusion: The Bethesda classification had high diagnostic accuracy, with the risk of malignancy consistent with the Bethesda findings. Classifying malignancy as “malignant” and “suspicious for malignancy” yielded the most favorable diagnostic properties for FNAC.

7812 Community Practice Setting Experience in Evaluation of Incidental Thyroid Nodules

Abstract Disclosure: N. Abate: None. H. Rhodes: None. M. Horlavadi: None. B. Adams-Huet: None. M. Chandalia: Advisory Board Member; Self; Boehringer Ingelheim. Speaker; Self; Boehringer Ingelheim, Eli Lilly & Company, Novo Nordisk. Background: There is a significant increase in detection of incidental thyroid nodules due to increase in routine screening ultrasounds at church, workplace, and health fairs, increase in routine ultrasound in primary care clinics and incidental finding of thyroid nodule during carotid artery ultrasound. These patients are then referred for thyroid nodule fine needle aspiration biopsy. Aim of this study was to evaluate real world data in frequency of thyroid cancer in patients referred for incidental thyroid nodule to a nonacademic Endocrinology clinic utilizing centralized collection of cytology and molecular analysis. Method: Medical records were reviewed for consecutive FNA of incidental thyroid nodule in an Endocrinology clinic in greater Houston from 2021 to 2023. FNA was performed in patients selected based on ACR TI-RADS classification. Patients with Bethesda score of 3 or more had molecular testing with Thyroseq performed. Patients with intermediate or high probability of cancer on Thyroseq as well as Patients with Bethesda 4 and 5 on cytopathology were referred for surgery. Surgical pathology was obtained in patients who underwent surgery. Data was tabulated and analyzed using SAS. Results: A total of 304 subjects, 267 Female and 37 males, age 57 ± 13, nodule size 2.69 ± 1.4 (mean ± SD), had thyroid nodule FNA between 2021 and 2023. Of these FNA, 23 (7.5%) sample collections were insufficient, 233 (77.3%) were benign (Bethesda 2), 46 (15%) were Atypia of undetermined significance or Suspicious for malignancy. Of those subjects with Bethesda 3 or higher, 36 patients had molecular testing by Thyroseq Method. Fifteen patients had intermediate and high risk finding on Thyroseq. Thirty-four subjects had surgery and 8 patients had malignancy on surgical pathology. One patient was identified as Medullary Thyroid cancer on Thyroseq, confirmed by surgery. Frequency of malignancy in incidentally detected thyroid nodule in the whole group was 2.6%, those with Bethesda 3 and more was 17.4% and those with Thyroseq intermediate or high risk was 27%. Conclusion: Availability of centralized cytopathology and reflex molecular testing to Community practice settings helps reducing unnecessary thyroid surgeries in patients with incidental thyroid nodules. Presentation: 6/1/2024

6511 Provider Opinions on Holding Antiplatelet and Anticoagulant Drugs Prior to Thyroid Nodules FNA Biopsy: A Survey Study

Abstract Disclosure: M.D. Lundholm: None. P.P. Rao: None. Objective: It is thought that anticoagulant (AC) or antiplatelet (AP) therapy at the time of thyroid nodule fine needle aspiration biopsy (TNFNAB) may increase the risk of non-diagnostic results and post-procedure hematomas. However, interrupting a patient’s AC or AP can lead to procedural delays or have thrombotic consequences. Since there is currently no consensus on whether or not to hold these medications, this study aims to survey the expertise of our providers across multiple specialties. Methods: A survey was sent out to Cleveland Clinic providers who have performed TNFNABs for patients with an active prescription for AC or AP since 2010. Providers were asked if they routinely held a number of blood thinner medication classes and included a free response section for open-ended comments. Results: The survey responses represented 60 providers (of 68 invited, 88% response rate). Respondents were 51.7% medical endocrinologists, 30% interventional radiologists, 13% surgical endocrinologists, and 5% ENTs. Of respondents, 13.3% held aspirin 81 mg, 15.0% held aspirin 325 mg, 41.7% held other antiplatelet agents, 73.3% held warfarin, 43.3% held direct oral anticoagulants (DOACs), and 43.3% held heparin. No department was uniform in practice, with the least agreement (responses closest to 50%) amongst medical endocrinologists. In a subset of 15 providers who have performed ≥100 TNFNABs on patients with AC/AP, a consensus emerged not to hold aspirin at any dose, but there was no agreement in any other AC/AP categories (hold rates ranging 53.5-66.6%). Free response themes reiterated that the main concerns for continuing blood thinners are hematomas and non-diagnostic results. Other comments included consideration of the nodule features such as location as well as strategies used to lower risk for hematomas (i.e., small-gauge needles, ice, holding pressure). A couple responses referred to the Society of Interventional Radiology (SIR) and the International Society on Thrombosis and Haemostasis (ISTH) guidelines which offer INR and platelet goal recommendations prior to any procedure with a low bleeding risk. Discussion: A survey of Cleveland Clinic providers demonstrated that ≥85% continue aspirin therapies prior to TNFNAB. However, there is no such agreement in any other category of AC/AP medication, even amongst the most experienced providers. The closest guidelines available come from SIR and ISTH and rely on recent platelet and/or INR information, which may not be available in routine endocrinology practice. The caveat is that these recommendations are not specific to TNFNAB and do not take into account the nuances of this procedure. Conclusion: There is wide variation in provider opinions and practice patterns regarding AC and AP medications prior to TNFNAB. This highlights the need for further study into the safety and adequacy of TNFNAB performed on uninterrupted AC or AP therapy. Presentation: 6/3/2024

Clinical risk factors and cancer risk of thyroid imaging reporting and data system category 4 A thyroid nodules

PurposeBeyond the Thyroid Imaging Reporting and Data System (TIRADS) classification of thyroid nodules, additional factors must be weighed in the decision to perform fine needle aspiration (FNA). In this study, we aimed to identify risk factors for malignancy in patients with ultrasound-classified Chinese-TIRADS (C-TIRADS) 4 A nodules.MethodsPatients who underwent thyroid FNA at our institution between May 2021 and September 2022 were enrolled. We collected demographic data, including age, sex, previous radiation exposure, and family history. An in-person questionnaire was used to collect lifestyle data, such as smoking habits and alcohol consumption. Body mass index (BMI) was calculated. The serum levels of thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TGAb) were measured. Prior to FNA, ultrasonic inspection reports were reviewed. The cytologic diagnoses for FNA of thyroid nodules followed the Bethesda System for Reporting Thyroid Cytopathology (2017).ResultsAmong the 252 C-TIRADS 4 A nodules, 103 were malignant. Compared to those in the benign group, the patients in the malignant group had a younger age (42.2 ± 13.6 vs. 51.5 ± 14.0 years, P < 0.001). Logistic regression showed that advanced age was associated with a lower risk of malignancy in C-TIRADS 4 A nodules (OR = 0.95, 95% CI 0.93 ~ 0.97, P < 0.001). We demonstrated a decreased risk of malignancy in patients with 48.5 years or older.ConclusionAdvanced age was associated with a decreased risk of malignancy in patients with C-TIRADS 4 A nodules. This study indicated that in addition to sonographic characteristics, patient age should be considered when assessing the risk of malignancy.

Discriminating Interpatient Variabilities of RAS Gene Variants for Precision Detection of Thyroid Cancer.

Interpatient variabilities in genomic variants may reflect differences in tumor statuses among individuals. To delineate interpatient variabilities in RAS variants in thyroid tumors based on the fifth World Health Organization classification of thyroid neoplasms and assess their diagnostic significance in cancer detection among patients with thyroid nodules. This prospective diagnostic study analyzed surgically resected thyroid tumors obtained from February 2016 to April 2022 and residual thyroid fine-needle aspiration (FNA) biopsies obtained from January 2020 to March 2021, at Mount Sinai Hospital, Toronto, Ontario, Canada. Data were analyzed from June 20, 2022, to October 15, 2023. Quantitative detection of interpatient disparities of RAS variants (ie, NRAS, HRAS, and KRAS) was performed along with assessment of BRAF V600E and TERT promoter variants (C228T and C250T) by detecting their variant allele fractions (VAFs) using digital polymerase chain reaction assays. Interpatient differences in RAS, BRAF V600E, and TERT promoter variants were analyzed and compared with surgical histopathologic diagnoses. Malignancy rates, sensitivity, specificity, positive predictive values, and negative predictive values were calculated. A total of 438 surgically resected thyroid tumor tissues and 249 thyroid nodule FNA biopsies were obtained from 620 patients (470 [75.8%] female; mean [SD] age, 50.7 [15.9] years). Median (IQR) follow-up for patients who underwent FNA biopsy analysis and subsequent resection was 88 (50-156) days. Of 438 tumors, 89 (20.3%) were identified with the presence of RAS variants, including 51 (11.6%) with NRAS, 29 (6.6%) with HRAS, and 9 (2.1%) with KRAS. The interpatient differences in these variants were discriminated at VAF levels ranging from 0.15% to 51.53%. The mean (SD) VAF of RAS variants exhibited no significant differences among benign nodules (39.2% [11.2%]), noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTPs) (25.4% [14.3%]), and malignant neoplasms (33.4% [13.8%]) (P = .28), although their distribution was found in 41.7% of NIFTPs and 50.7% of invasive encapsulated follicular variant papillary thyroid carcinomas (P < .001). RAS variants alone, regardless of a low or high VAF, were significantly associated with neoplasms at low risk of tumor recurrence (60.7% of RAS variants vs 26.9% of samples negative for RAS variants; P < .001). Compared with the sensitivity of 54.2% (95% CI, 48.8%-59.4%) and specificity of 100% (95% CI, 94.8%-100%) for BRAF V600E and TERT promoter variant assays, the inclusion of RAS variants into BRAF and TERT promoter variant assays improved sensitivity to 70.5% (95% CI, 65.4%-75.2%), albeit with a reduction in specificity to 88.8% (95% CI, 79.8%-94.1%) in distinguishing malignant neoplasms from benign and NIFTP tumors. Furthermore, interpatient differences in 5 gene variants (NRAS, HRAS, KRAS, BRAF, and TERT) were discriminated in 54 of 126 indeterminate FNAs (42.9%) and 18 of 76 nondiagnostic FNAs (23.7%), and all tumors with follow-up surgical pathology confirmed malignancy. This diagnostic study delineated interpatient differences in RAS variants present in thyroid tumors with a variety of histopathological diagnoses. Discrimination of interpatient variabilities in RAS in combination with BRAF V600E and TERT promoter variants could facilitate cytology examinations in preoperative precision malignancy diagnosis among patients with thyroid nodules.

Accuracy of ultrasound in predicting thyroid malignancy: a comparative analysis of the ACR TI-RADS and ATA risk stratification systems.

Thyroid nodules are very common in clinical practice, and ultrasound has long been used as a screening tool for their evaluation. Several risk assessment systems based on ultrasonography have been developed to stratify the risk of malignancy and determine the need for fine-needle aspiration in thyroid nodules, including the American Thyroid Association (ATA) system and the American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS). The aim of this study was to compare the performance of the ATA and ACR TI-RADS systems in predicting malignancy in thyroid nodules based on the nodules' final histopathology reports. We performed a retrospective review of medical records to identify patients who underwent thyroid surgery at King Abdulaziz University from 2017 to 2022. The ultrasound features of the nodules with confirmed histopathology (benign versus malignant) were evaluated. Both ATA and ACR TI-RADS scores were documented. The analysis included 191 patients who underwent thyroid surgery and fulfilled the inclusion criteria. Hemithyroidectomy was performed in 22.5% of the patients, and total thyroidectomy was performed in 77.0% of them. In all, 91 patients (47.6%) were found to have malignant nodules on histopathology. We then compared the histopathology reports with the preoperative ultrasonographic risk scores. The estimated sensitivity and specificity in identifying malignant nodules were, respectively, 52% and 80% with the ATA system and 51.6% and 90% with the ACR TI-RADS system. Both ATA and ACR TI-RADS risk stratification systems are valuable tools for assessing the malignancy risk in thyroid nodules. In our study, the ACR TI-RADS system had superior specificity compared with the ATA system in predicting malignancy among high-risk lesions.

The Utility of ACR TI-RADS in Predicting False-Negative Fine Needle Aspiration for Thyroid Cancer.

Thyroid nodule fine needle aspiration (FNA) biopsies are associated with a low false-negative rate. There is limited data regarding the predictive value of American College of Radiology Thyroid Imaging Reporting and Data System for false-negative FNA. This single-center retrospective study evaluated 119 patients who underwent thyroidectomy. The association of TR category, along with other clinical variables, with false-negative FNA was evaluated. The overall false-negative rate of FNA was 10.8% (n = 9). False-negative FNAs were associated with younger age (mean 42years vs 50.6years, P = .04), larger nodule size (mean 4.4cm vs 3.2cm, P = .03), and a lower TR category (median 3 v 4, P = .01). Lower TR category, younger age, and larger nodule size were associated with false-negative FNA of thyroid nodules. These findings should be taken into context when counseling patients with thyroid nodules who have a benign FNA.

The Diagnostic Utility of Repeat Fine-needle Aspirations of Benign Thyroid Nodules.

Objective This study aims to analyze the diagnostic utility of multiple repeat FNA on thyroid nodules with initially benign diagnosis. Methods In a 5-year period, 1658 thyroid nodules with initially benign FNAs were retrospectively reviewed and followed for subsequent resection and repeat biopsy. Results Out of 2150 thyroid nodules, 1658 (77.1%) were diagnosed as benign on FNAs. The average age was 57.4 years (range 11-93 years), and most were females (83.8%). Repeat FNA was performed on 183 benign nodules, of which 141 (8.5%) were sampled a second time and 42 (2.5%) had 2 or more repeat samplings. For the benign nodules without repeat FNAs, 124 had benign resection. Of cases with one-time repeat FNA, most (n=101) remained benign on repeat FNAs, 13 of which were benign on resection. Eleven had atypical repeat FNAs, 5 were resected, 4 of which were benign and one was atypical follicular neoplasm with HRAS and TERT promoter mutations. Of cases with multiple repeat FNA, most (n=35) were still benign on repeat FNAs, one had benign resection. Two had atypical repeat biopsies, one was PTC on resection with CCD6::RET fusion. The positive predictive value significantly decreased from 41.1% on single FNA to 8.3% on one-time repeat (p<0.001) and 16.7% on multiple repeat (p=0.002). The total cost for workup of previously benign nodules was $285,454. Conclusions Repeat FNA biopsies did not provide an additional diagnostic value in the evaluation of benign thyroid nodules, and often led to unwarranted follow-up procedures and significantly increased health care cost.

Comparison of Cytological Adequacy between 23- and 25-Gauge in Ultrasound-Guided Fine-Needle Aspiration of Thyroid Nodules: A Single-Center Prospective Study.

Approximately 15% of fine-needle aspiration (FNA) of thyroid nodules are considered nondiagnostic. Several factors are potentially involved, including clinical and nodule features but also the gauge (G) of the needle used. However, few studies have compared the cytological adequacy obtained with different gauge needles and the data are controversial. We aimed to evaluate cytological adequacy results using 23- or 25-G needles. This study is an observational and prospective study of thyroid nodules submitted to ultrasound-guided FNA. The procedure was performed randomly using 23- or 25-G needles. The samples were reported by different cytopathologists who were blinded to the information of the gauge of the needle used. Statistical analysis was performed to compare cytological adequacy of FNA between the two groups. A total of 177 thyroid nodules were included - 98 (55.4%) using 23-G and 79 (44.6%) using 25-G needles. The 23-G group presented a higher rate of cytological adequacy (69.4% [68/98] vs. 46.8% [37/79], p = 0.002). No differences were found between the two groups regarding patient or nodule characteristics. On logistic regression, 23-G needles correlated with better cytological adequacy (unadjusted OR 2.57 [95% CI: 1.39-4.77]), even after adjusting for nodule dimension, location, and type of cytology (slides +/- additional liquid-based cytology) (adjusted OR 2.44 [95% CI: 1.23-4.84]). The gauge of the needle used was found to be an independent predictor of cytological adequacy, with 23-G needles providing more adequate samples. Further investigation is needed to confirm our results in order to stablish the optimal diagnosis technique.

Influence of maximum diameter on fine-needle aspiration biopsy outcomes in ACR TI-RADS 5 thyroid nodules.

Fine needle aspiration (FNA) biopsy is a widely accepted method for diagnosing thyroid nodules. However, the influence of maximum diameter (MD) of ACR TIRADS 5 (TR5) thyroid nodules on the FNA outcomes remains debated. This study examined the influence of MD on the FNA outcomes and investigated the optimal MD threshold for FNA in TR5 nodules. We conducted a retrospective analysis of 280 TR5 thyroid nodules from 226 patients who underwent FNA from January to June 2022 in our department. Probably malignant (PM) group was defined as Bethesda V in cytopathology with confirmed BRAF V600E mutation or Bethesda VI, the other cytopathology outcomes were defined as probably benign (PB) group. We examined factors influencing malignant cytopathology outcomes and determined the optimal MD threshold for FNA in TR5 nodules using logistic regression and restricted cubic spline (RCS) analysis. Among these nodules, 58.2% (163/280) had PM outcomes. The PM group had a significantly larger MD than the PB group [6.5mm (range 5.0-8.4) vs. 5.3mm (range 4.0-7.0), p < 0.001]. In multivariate logistic regression fully adjusted for confounders, MD was significantly associated with PM outcomes [odds ratio 1.16, 95%CI 1.05-1.31; p = 0.042]. The highest quartile of MD had a greater likelihood of PM outcomes compared to the lowest quartile [odds ratio 4.71, 95% CI 1.97-11.69, p = 0.001]. The RCS analysis identified 6.2mm as the optimal MD threshold for FNA in TR5 nodules. MD significantly affects the probability of malignant outcomes in FNA of TR5 thyroid nodules. A MD threshold of ≥6.2mm is suggested for FNA in these nodules.

Bethesda Category III thyroid nodules: descriptive cytological aspects of a series

BackgroundThe Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is used for cytopathological diagnosis of fine needle aspiration (FNA) of thyroid nodules (TN). Diagnosis of Bethesda Category III (CIII) has estimated malignancy rates of around 10%-30%, which vary between different institutions. Objective. To review cases of FNA interpreted as CIII thyroid nodules. To evaluate cytopathological criteria used to interpret FNA for CIII thyroid nodules and the associations between cytological and radiological aspects. To determine the malignancy rate of thyroid nodules classified as CIII, based on the correlation with surgical procedure. Methods. Retrospective study of FNA’s cytologic criteria of TN classified as CIII, carried out between 2010 and 2016. The patients included in the study were those who underwent the first FNA in the service and who were diagnosed with CIII. The patients had their cytological slides and medical records reviewed to detect the conduct flow followed after the CIII diagnosis. All cases that had histological slides available of their thyroidectomy products, total or partial, reviewed. The associations between clinical, histological and cytological findings were statistically studied. Results. Among 63 patients with resected nodules, 17 (27%) were malignant, 13 of which were papillary thyroid carcinomas. Among the benign cases, 18 patients (28.1%) had chronic lymphocytic thyroiditis/Hashimoto’s thyroiditis. Papillae (p = .004) was the criterion best associated with the diagnosis of malignancy. Conclusion. The malignancy rate was consistent with the rate of malignancy predicted in the TBSRTC. It is important to point out that the sample of this study is relatively small, which compromises specific evaluations and reduces the robustness of the observed data. CIII is extensively studied in the literature, however there is still a need for more precise studies regarding the correlations between cytological findings and other parameters. Probably, more than other categories, CIII may require a combination of cytological, radiological and clinical interpretation, with pathology leading role in this diagnosis process.

Photoacoustic Tomography Combined with Ultrasound Mapping for Guiding Fine-Needle Aspiration of Thyroid Nodules: A Pilot Study

This study aims to explore the feasibility of fine-needle aspiration biopsy (FNAB) under dual modal photoacoustic tomography(PAT)/ultrasound (US) imaging. A total of 25 patients who have thyroid nodules with thyroid imaging reporting and data system (TIRADS) 3 and 4 (malignant risk &lt;85%) were recruited. The specimens obtained from the PAT/US-guided FNAB were collected for cytology analysis. Cytological diagnoses for the 25 patients were classified in perspective of the Bethesda system for reporting thyroid cytopathology diagnostic category (DC) I: 4%(1/25); DC II: 12% (3/25); DC III: 20% (5/25); DC IV: 8% (2/25); DC V: 32% (8/25); and DC VI: 24% (6/25). The DC I nodule exhibited inadequate cytology and had structural characteristic of predominant calcifications in PAT/US mapping. The DC V-VI nodules showed lower photoacoustic (PA) signals compared to the DC I-IV nodules. Regions with a high PA signal demonstrated a significant number of erythrocytes in FNAB cytology. Moreover, nodules with microcalcifications did not show a significant difference compared to their surroundings in the PA signal, while nodules with macrocalcifications gave higher PA signals compared to their surroundings. The conclusions are as follows: combining US with PAT can evaluate the structure and function of thyroid nodules in vivo. This study demonstrates that dual modal PAT/US imaging has the potential to be an effective clinical tool to guide FNAB of thyroid nodules.

FRI470 The Impact Of COVID-19 Lockdown On Thyroid Fine Needle Aspiration Volume And Malignancy Rate

Abstract Disclosure: K. Larkin: None. J. Li: None. T.C. Brandler: None. F. Ling: None. D.A. Cohen: None. Background: During the COVID-19 pandemic many elective procedures were postponed, including thyroid nodule fine needle aspiration biopsies (FNABs). These delays may have led to a lag in diagnosis of thyroid cancer. Our study aims to determine whether there were fewer FNABs performed during and immediately after lockdown, with subsequent higher than baseline volume in the 6–12-months after, before returning to baseline. We hypothesized that due to a stringent threshold for biopsy referral, malignancy rates would be higher during and immediately after lockdown before decreasing to lower than baseline. Our study’s findings may aid in future determination of procedure prioritization during crises. Methods: This single-center retrospective chart review was performed at the Endocrinology Clinic at Robert Wood Johnson Hospital at Rutgers University. The study included over 1800 samples collected from 04/19-03/21 in patients age &amp;gt; 18 years. Patients with history of thyroid cancer were excluded. We assessed raw number and rate of malignancy diagnosed in 60-day periods defined as “pre-lockdown,” “during lockdown,” and “post-lockdown.” We defined malignant FNAB cytology, based on the Bethesda scoring system, as suspicious or positive for malignancy (score of V or VI). Summary statistics were calculated using means or percentages as appropriate. Results: 1862 thyroid nodule FNABs were analyzed. 1046 FNABs were performed in pre-lockdown (4/1/2019-3/10/2020), for an average of 182.44 FNABs per 60-day period. 70 FNABs were performed during lockdown (3/10/2020-6/2/2020), for an average of 50 FNABs per 60-day period. This represents a 72.59% decline in FNAB volume. During post-lockdown, the average number of FNABs performed were 150, 130, 157, 132.78 and 185.17 per 60-day time period. During pre-lockdown, 48 FNABs met our criteria for malignancy, with a true positivity rate of 4.58%. During lockdown, 4 FNABs met criteria, for a true positivity rate of 5.71%. This represents an increase in positivity of 25%. During post-lockdown, true positivity rates were 3.4%, 3.8%, 3.8%, 5.2%, and 5.7%. Discussion and Conclusion: During the COVID-19 lockdown, volume of thyroid nodule FNABs decreased by 72.59% and nodules were 25% more likely to be positive. During post-lockdown, the number of FNABs began to return to baseline. Malignancy rates initially declined and then surpassed pre-lockdown rates. We speculate that given the decrease in number of FNABs performed during lockdown combined with the increased rate of malignancy, thyroid nodules determined to be clinically significant were prioritized. With that, it is likely that malignant nodules were missed, or diagnosis delayed, potentially accounting for higher rates in later post-lockdown periods. This information can aid future situations of crisis, as a more organized and informed approach can give patients the opportunity to seek elective procedures. Presentation: Friday, June 16, 2023

Comparison of the diagnostic value of fine needle aspiration and ultrasound in thyroid pathology

Fine needle aspiration (FNA) biopsy has been a powerful tool in the preoperative diagnosis of thyroid nodules for more than 60 years. The Bethesda scale standardizes the results of cytology and is a tool for interaction between the laboratory and the clinician. At the same time, there is a stratification of ultrasound signs of thyroid lesions according to the TI-RADS scale. In this regard, it became necessary to determine the diagnostic value of ultrasound signs of thyroid lesions, stratified by TI-RADS, in comparison with the results of a biopsy, classified by the Bethesda scale.AIM: a comparative assessment of the results of FNA and ultrasound in determining indications for the surgical treatment of thyroid nodules.MATERIALS AND METHODS: for 2018–2021 in the surgical department of the SCC №2 of the Petrovsky National Research Centre of Surgery, 859 FNA were performed. For comparative analysis, 141 patients who underwent surgery for thyroid nodules were selected. All patients at the preoperative stage underwent FNA with stratification of the results according to the Bethesda scale and ultrasound of the thyroid gland with stratification according to the EU-TI-RADS scale.RESULTS: FNA showed high diagnostic accuracy and sensitivity, preoperative thyroid ultrasound had high specificity, but low sensitivity. The high diagnostic value of FNA was confirmed by statistical analysis of the obtained data (OR 31.29 95% CI 2.20–4.69, RR 13.28 95% CI 1.46–3.71). When analyzing preoperative ultrasound, it was not possible to obtain reliable statistical results (OR 2.99 95% CI 0.34-1.85, RR 1.97 95% CI 0.23-1.12).CONCLUSION: Ultrasound of the thyroid gland cannot replace FNA in thyroid nodules. Biopsy remains the main diagnostic method for nodular goiter. The main objective of TI-RADS-stratified ultrasound is to select patients for subsequent FNA.

Facilitation of Definitive Cancer Diagnosis With Quantitative Molecular Assays of BRAF V600E and TERT Promoter Variants in Patients With Thyroid Nodules

Molecular testing of the presence of pathogenic genomic variants in a tumor without quantifying the variant allele fraction (VAF) does not differentiate the variation extent among tumors, often resulting in an inconclusive diagnosis because of interpatient variability. To examine the association between the quantification of VAFs of BRAF V600E and TERT promoter variants and a definitive cancer diagnosis of thyroid tumors. This diagnostic study analyzed a cohort of 378 surgically resected thyroid tumors with a maximum dimension of 1 cm or larger between March 15, 2016, and March 16, 2020, and a separate cohort of 217 residual thyroid fine-needle aspiration (FNA) biopsy specimens obtained from January 22, 2020, to March 2, 2021, at Mount Sinai Hospital, Toronto, Ontario, Canada. Data analysis was conducted between February 1, 2021, and February 1, 2023. Quantitative VAF assays of BRAF V600E and TERT promoter variants (C228T and C250T) were performed by digital polymerase chain reaction molecular assays. The VAFs of BRAF V600E and TERT promoter variants were correlated with tumor histologic diagnoses and histopathologic features to delineate the association of VAF assays with tumor malignancy. The receiver operating characteristic curve analysis, sensitivity, specificity, positive predictive value, negative predictive value, and logistic regression analysis based on follow-up histopathologic types were used to determine the diagnostic utility of the quantitative molecular assays. A total of 595 specimens, including 378 surgically resected thyroid tumors and 217 thyroid nodule FNA biopsy specimens, were collected from 580 patients (436 [75.2%] female with a mean [SD] age of 50 [16] years and 144 [24.8%] male with a mean [SD] age of 55 [14] years). Sensitive VAF assays of 378 thyroid tumors revealed the presence of the BRAF V600E variant in 162 tumors (42.9%), with 26 (16.0%) at a low VAF of 1% or less and 136 (84.0%) at a high VAF of greater than 1%, and the presence of TERT promoter variants in 49 tumors (13.0%), including 45 C228T variants (91.8%), 15 (33.3%) of which were quantified as having a low VAF (≤1%) and 30 (66.7%) as having a high VAF (>1%), and 4 C250T variants (8.2%) with VAFs between 40.0% and 47.0%. All tumors detected with BRAF V600E and/or TERT promoter variants, whether at low or high VAFs, received a definitive cancer diagnosis. Further analysis delineated a significant association between high VAFs of either variant individually or different VAF levels for both variants in coexistence and aggressive histopathologic features of tumors. Excluding low VAFs assisted in identifying patients at an intermediate-to-high risk of recurrence (odds ratio, 5.3; 95% CI, 1.9-14.6; P = .001). The VAF assays on the residual FNA biopsy specimens showed a high agreement to those on surgical tissues (κ = 0.793, P < .001) and stratified malignancy in 40 of 183 indeterminate FNA cases (21.9%), with a sensitivity of 93.8% (95% CI, 67.7%-99.7%), specificity of 90.0% (95% CI, 75.4%-96.7%), positive predictive value of 78.9% (95% CI, 53.9%-93.0%), and negative predictive value of 97.3% (95% CI, 84.2%-99.9%). This diagnostic study suggests that sensitive quantitative VAF assays of BRAF V600E and TERT promoter variants can elucidate the interpatient variability in tumors and facilitate a definitive cancer diagnosis of thyroid nodules by differentiating the variation extent of genomic variants, even at low VAFs.

Influencing Factors and Prediction Model of Performance of Needle Visualization in Fine Needle Aspiration of Thyroid Nodules

Objective To investigate the influencing factors and establish a model predicting the performance of needle visualization in fine-needle aspiration (FNA) of thyroid nodules. Methods This study prospectively included 175 patients who underwent FNA of thyroid nodules in the Department of Ultrasound in China-Japan Friendship Hospital and compared the display of the needle tips in the examination of 199 thyroid nodules before and after the application of needle visualization.We recorded the location,the positional relationship with thyroid capsule,ultrasonic characteristics,and the distribution of the soft tissue strip structure at the puncture site of the nodules with unclear needle tips display before using needle visualization.Furthermore,according to the thyroid imaging reporting and data system proposed by the American College of Radiology,we graded the risk of the nodules.Lasso-Logistic regression was employed to screen out the factors influencing the performance of needle visualization and establish a nomogram for prediction. Results The needle tips were not clearly displayed in the examination of 135 (67.8%) and 53 (26.6%) nodules before and after the application of needle visualization,respectively,which showed a significant difference (P<0.001).Based on the positional relationship between the nodule and capsule,anteroposterior/transverse diameter (A/T) ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site,a nomogram was established to predict the probability of unclear display of the needle tips after application of needle visualization.The C-index of the prediction model was 0.75 (95%CI=0.67-0.84) and the area under the receiver operating characteristic curve was 0.72.The calibration curve confirmed the appreciable reliability of the prediction model,with the C-index of 0.70 in internal validation. Conclusions Needle visualization can improve the display of the needle tip in ultrasound-guided FNA of thyroid nodules.The nomogram established based on ultrasound features such as the positional relationship between the nodule and capsule,A/T ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site can predict whether needle visualization is suitable for the examination of nodules.

Multimodality US versus Thyroid Imaging Reporting and Data System Criteria in Recommending Fine-Needle Aspiration of Thyroid Nodules.

Background Current guidelines recommend the use of conventional US for risk stratification and management of thyroid nodules. However, fine-needle aspiration (FNA) is often recommended in benign nodules. Purpose To compare the diagnostic performance of multimodality US (including conventional US, strain elastography, and contrast-enhanced US [CEUS]) with the American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) in the recommendation of FNA for thyroid nodules to reduce unnecessary biopsies. Materials and Methods In this prospective study, 445 consecutive participants with thyroid nodules from nine tertiary referral hospitals were recruited between October 2020 and May 2021. With univariable and multivariable logistic regression, the prediction models incorporating sonographic features, evaluated with interobserver agreement, were constructed and internally validated with bootstrap resampling technique. In addition, discrimination, calibration, and decision curve analysis were performed. Results A total of 434 thyroid nodules confirmed at pathologic analysis (259 malignant thyroid nodules) in 434 participants (mean age, 45 years ± 12 [SD]; 307 female participants) were included. Four multivariable models incorporated participant age, nodule features at US (proportion of cystic components, echogenicity, margin, shape, punctate echogenic foci), elastography features (stiffness), and CEUS features (blood volume). In recommending FNA in thyroid nodules, the highest area under the receiver operating characteristic curve (AUC) was 0.85 (95% CI: 0.81, 0.89) for the multimodality US model, and the lowest AUC was 0.63 (95% CI: 0.59, 0.68) for TI-RADS (P < .001). At the 50% risk threshold, 31% (95% CI: 26, 38) of FNA procedures could be avoided with multimodality US compared with 15% (95% CI: 12, 19) with TI-RADS (P < .001). Conclusion Multimodality US had better performance in recommending FNA to avoid unnecessary biopsies than the TI-RADS. Clinical trial registration no. NCT04574258 © RSNA, 2023 Supplemental material is available for this article.

Ultrasound features affecting the sample adequacy after fine-needle aspiration of thyroid nodules with different risk stratification.

The inadequacy samples caused by the internal characteristic structure of thyroid nodules are difficult to be solved. To evaluate the ultrasound features affecting the sample adequacy after fine-needle aspiration (FNA) of thyroid nodules with different risk stratification. 592 thyroid nodules that underwent ultrasound-guided FNA were included in this retrospective study. The sample obtained by FNA were classified as inadequacy and adequacy according to the cytopathological results. Ultrasound features (ie., size, position, cystic predominance, composition, echo, shape, margin, and superficial annular calcification status) of the nodules were recorded and compared between the inadequacy sample group and adequacy sample group. Multiple logistic regression shows that preponderant cystic proportion (OR, 0.384; P = 0.041), extremely hypoechogenicity and hypoechogenicity (OR, 6.349; P = 0.006) were the independent influencing factors of inadequate samples after FNA in benign expected nodules. In addition, nodule size ≤10 mm (OR, 1.960; P = 0.010) and superficially annular calcification (OR, 4.600; P < 0.001) were independent influencing factors for inadequate samples after FNA in malignant expected nodules. The ultrasound features of hypoechogenicity or high cystic proportion in benign expected nodules and that of small size or annular calcification in malignant expected nodules were the risk factors for inadequacy samples by US-guided FNA.