Importance of FNA Technique for Decreasing Non-diagnostic Rates in Thyroid Nodules

Non-Diagnostic Fine Needle Aspiration of Thyroid Nodules: Review of Pre-disposing Factors

BACKGROUND

Fine needle aspiration (FNA) of thyroid nodules is the gold standard screening test for thyroid malignancy. Unfortunately, FNA may produce insufficient material for diagnosis. If nodules requiring FNA with a higher risk for non-diagnostic (ND) cytology could be identified pre-procedure, this might allow better patient guidance and potentially facilitate an altered approach to FNA.

SUMMARY

The literature investigating risk factors for ND cytology was reviewed, including studies of patient factors, sonographic or nodule factors, and procedural factors. Twenty-five studies that included assessment of at least two potential factors in ND outcomes for initial FNA were identified. Individual factors were evaluated in terms of the general consensus of studies reporting either a positive significant association with ND cytology or no association.

CONCLUSION

Most patient and nodule factors lack consensus as far as their association with ND cytology across these studies. However, a number of study design improvements suggested by this review could realistically be incorporated into higher powered future studies. Novel factors such as tissue composition anterior to the nodule or the age of the patient could also be investigated in future work. Operator experiences is the most convincing procedural factor, and approaches to future studies of the FNA technique itself are proposed. That said, the factors with consensus amongst studies can be seen leading candidates for this future research, and the published studies illuminate a number of as yet unexplored factors that could in many cases be studied retrospectively.

THE IMPACT OF PATIENT ANXIETY AND PAIN PERCEPTION ON THE ADEQUACY OF THYROID FINE-NEEDLE ASPIRATION BIOPSY SAMPLES: A PROSPECTIVE STUDY

Background

Fine-needle aspiration biopsy (FNAB) is the most accurate diagnostic method to assess the malignancy risk of thyroid nodules. However, non-diagnostic results may delay diagnosis, cause unnecessary interventions, and distress patients.

Aim

We aimed to determine whether a correlation exists between patients' situational anxiety, pain perception and non-diagnostic cytology results.

Methods

The prospective study included patients who underwent thyroid FNAB at the Endocrinology Clinic of Sultan Abdulhamid Training and Research Hospital between 11/2022 and 02/2023. The State-Trait Anxiety Inventory (STAI) questionnaire and visual analogue scale (VAS) assessed situational anxiety and pain in patients undergoing biopsy procedures. We evaluated whether the STAI-S and VAS score is related to non-diagnostic results.

Results

Of the 119 patients included in the study, 98 were female, and 21 were male. 25 (21%) nodules were non-diagnostic. The patients' mean STAI-S score before the biopsy was 47.31±12.37, and the mean VAS score after the thyroid biopsy was 2.57±1.51. A statistically significant relation was found between the patient's STAI-S score and VAS score and the cytology result of non-diagnostic (p= 0.001 and p=0.008). In univariate logistic regression, high pre-procedural anxiety (OR:3.09, 95% CI:1.07-8.94, P =0.037) and VAS score (OR:1.57, 95% CI: 1.17-2.10, P =0.002) were associated with non-diagnostic cytology. In multivariate logistic regression analysis, VAS score (OR: 1.59, 95% CI: 1.07-2.34, p=0.019) was still an independent factor related to specimen adequacy.

Conclusions

Anxiety level and pain perception during FNAB may be considered risk factors for non-diagnostic cytology. Thus, reducing anxiety and pain may decrease the incidence of non-diagnostic outcomes.

Analysis of the influencing factors on fine-needle aspiration biopsy results of the thyroid

Objective

The objective of the study is to analyze the influencing factors on the results of thyroid fine-needle aspiration biopsy (FNAB).

Method

A total of 339 patients who underwent FNAB in our hospital from December 2018 to July 2021 were retrospectively selected. The patients were chosen according to the gender ratio, age, and thyroid ultrasound characteristics and were divided into three groups: (1) a 22G needle vacuum aspiration group (Group 1, n = 85), (2) a 22G biopsy needle non-vacuum aspiration group (Group 2, n = 50), and (3) a 25G biopsy needle non-vacuum aspiration group (Group 3, n = 204). Patients in these groups were evaluated for determining the FNAB dissatisfaction rate of pathological samples. A bivariate regression analysis of independent risk factors related to the unsatisfactory pathological diagnosis of samples was performed.

Results

The specimen dissatisfaction rates of the three groups were 22/85 (25.9%), 15/50 (30%), and 18/186 (9.7%), respectively. The overall sample dissatisfaction rate was 55/339 (16.2%), and the sample satisfaction rate of Group 3 was higher than that of Groups 1 and 2 (P < 0.05). Logistic bivariate regression analysis showed that the age of the patients and the capillary sampling needles and aspiration methods were two independent risk factors for determining the dissatisfaction rate of FNAB pathological samples.

Conclusion

A 25G capillary sampling aspiration biopsy needle was selected to perform FNAB in thyroid nodules without vacuum aspiration, which could effectively improve the accuracy of FNAB results with a high specimen satisfaction rate.

Ultrasound-Guided Fine Needle Aspiration of Deep Thyroid Nodule: Is There a Correlation between the Nodule's Depth and Nondiagnostic Results?

Objective

To evaluate whether thyroid nodule depth correlates with nondiagnostic results in ultrasound-guided fine needle aspiration cytopathology.

Background

Many factors correlate with nondiagnostic ultrasound-guided fine needle aspiration cytology (FNAC) results, including older age, macrocalcification, small-sized nodules, aspirin medication, and cystic portion in more than 50% of the thyroid nodules. However, there are few studies which have examined whether there is a relationship between the depth of nodules and the percentage of nondiagnostic results in cytology (Bethesda category I). We conducted this study in order to investigate if such a correlation exists.

Materials and Methods

FNAC was performed on 283 thyroid nodules between January 2019 and December 2020. Cytological analyses of the nodules were reviewed and sorted as nondiagnostic and diagnostic according to the Bethesda score. Patient files and ultra sound (US) scans were reviewed for clinical information (such as age, sex, and ethnic group) and sonographic features of nodules (such as depth, size, cystic portion, type of calcification, and echogenicity) and were compared between the nondiagnostic and diagnostic nodule results. The depth of a nodule was calculated as the shortest distance from the skin to the most superficial border of the nodule in the axial plane, using our medical center's computer program, which allows reviewing all saved shots of the US scan.

Results

Age, sex, and ethnicity were not significantly different between the nondiagnostic group and the diagnostic group (p > 0.05). Nodule diameter, cystic portion, calcification, and echogenicity were also not associated with the frequency of nondiagnostic results. The depth of nodules ≥9 mm was correlated with nondiagnostic US-guided FNA cytological results (OR = 2.55, p=0.018).

Conclusions

Deep thyroid nodules correlated with nondiagnostic US-guided FNA cytological results. Further studies are needed for optimizing the approach to deep thyroid nodules in order to improve the efficacy of FNA in deep thyroid nodules.

Effect of needle gauge on thyroid FNA diagnostic rate

PURPOSE

Thyroid Bethesda classification system provides 6 diagnostic categories, the first being a sample deemed non-diagnostic or insufficient and requiring a subsequent second biopsy. Our objective was to evaluate differences in non-diagnostic fine needle aspiration (FNA) of thyroid nodules conducted with a 23-gauge(G) needle vs. those conducted with a 25 G needle.

METHODS

Data from 298 aspiration procedures using either 23 G or 25 G needles were collected, including cytological findings, ultrasound characteristics and patient demographics. The samples were classified as diagnostic or non-diagnostic according to final cytology.

RESULTS

There was no statistically significant difference between the 25 G and 23 G needles in terms of non-diagnostic rates (35.7%, 31.9%; p = 0.494). Nodules defined as cystic had higher non-diagnostic rates (p < 0.05). Older patients as well as cystic nodules were associated with a higher non-diagnostic rate (OR = 1.018, p = 0.047, OR = 13.533, p = 0.0001, respectively), while nodule size was associated with lower non-diagnostic rates (OR = 0.747, p = 0.017).

CONCLUSIONS

The use of 25 G needle did not produce a lower non-diagnostic rate when compared to 23 G needle. Larger nodules might increase diagnostic rates, while older patients and cystic nodules are prone to inadequate samples. Patients and caregivers should be aware that FNA of small or cystic nodules as well as nodules in older patients may result in a higher non-diagnostic rate. Further research comparing other needles gauges should be conducted.

Evaluation of thyroid nodules in the Brazilian Public Health Care System, Supplementary Health System, and Private Health System in the northeastern region of the State of São Paulo

OBJECTIVE

To obtain data about the evaluation of thyroid nodules (TNs) in the northeastern of the State of São Paulo, compared by health care type, and measure the performance of cytology as a screening test for thyroid cancer (TC).

METHODS

We collected data of 597 patients treated in the Brazilian public health care system (SUS), supplementary health (SH) and in private health system (PHS) in 2014. A total of 803 TNs were aspirated, and 125 patients underwent surgery.

RESULTS

The distribution of all cytologic results according to the Bethesda system was: I, 135 (16.8%); II, 475 (59.2%); III, 107 (13.3%); IV, 32 (4.0%); V, 20 (2.5%); VI, 34 (4.2%). The time between cytologic analysis and surgery was longer in the SUS than in the SH for TNs in general (p < 0.001) and for TNs with Bethesda V and VI cytology (p = 0.01). The sizes of the TNs and resected malignant TNs was larger in the SUS than in the SH (p = 0.001 and p = 0.02, respectively). The number of PHS surgeries was too small and was not compared. The prevalence of TC was 9.2% and 23.6% of them were treated in the SUS. Cytology showed a 93.6% sensitivity, 95.8% specificity, and 94.7% accuracy when Bethesda III and IV were excluded.

CONCLUSION

Cytology was a good screening test for TC categories Bethesda II, V, and VI. The differences between the SUS and SH indicate a need for improved access to consultations and specialized tests in the SUS.

Rapid on-site evaluation (ROSE) for fine needle aspiration of thyroid: benefits, challenges and innovative solutions

Rapid on-site evaluation/adequacy assessment (ROSE) is considered an essential component of thyroid fine needle aspiration (FNA) and many reported that it significantly decreases the nondiagnostic (ND) rate. The average reported ND rate without ROSE is about 20% and is improved by 12% when ROSE is implemented. However, the data also suggest that the improvement in ND rate after implementation of ROSE is directly related to the ND rate prior to ROSE and that it is mostly beneficial to aspirators with less experience. Several studies have also raised concerns regarding the impact of ROSE as it prolongs the procedure time, requires additional resources and increases the cost incurred by the additional fees. This resulted in a wide variation in the methodology applied to acquire the sample and implement ROSE across the globe with variation in the number of passes performed, stain utilized and the personnel reviewing the slides, e.g., cytotechnologists versus pathologist. This review summarized the literature reporting the impact of ROSE including its pros and cons, its accuracy and reproducibility, concordance between cytotechnologists and pathologists based on final diagnosis and highlights the different ways laboratories attempted to circumvent the challenges. In particular, the review highlights a unique approach practiced in Ito Hospital, Tokyo, Japan.

Determining whether surgeons perform thyroid fine-needle aspiration as well as radiologists: an analysis of the adequacy and efficiency of ultrasound-guided fine-needle aspiration performed by newly trained head and neck surgeons and radiologists

Background

Ultrasound-guided fine-needle aspiration (FNA) cytology is a crucial diagnostic technique used to assess thyroid nodules. In the past, ultrasound-guided FNA was performed mainly by radiologists. However, many surgeons are increasingly being trained for this procedure now. In this study, we aimed to compare the adequacy and efficiency of ultrasound-guided FNA performed by newly trained head and neck surgeons with experienced radiologists in a single institution. We also assessed the malignancy rates in nondiagnostic nodules and the differences between benign and malignant nodules.

Methods

This is a retrospective study. The data from patients who underwent ultrasound-guided FNA performed by surgeons or radiologists in two consecutive years were collected. Medical records, cytology results, and surgical pathology results were analyzed.

Results

During the study period, a total of 2,405 ultrasound-guided FNAs were performed on 2,163 patients. The head and neck surgeons and radiologists performed 1,132 and 1,273 ultrasound-guided FNA procedures, respectively. The nondiagnostic rate was 14.49% for surgeons and 15.40% for radiologists (P=0.533). There were no differences in patient age, gender, nodule size, and other sonographic characteristics between the groups of patients who were treated by radiologists versus surgeons. The median waiting time from biopsy appointment to performing ultrasound-guided FNA was 0 days for head and neck surgeons, and 6 days for radiologists (P<0.001). Of the 40 patients who had a repeat FNA or surgery, 19 (47.50%) had a malignancy. Preoperative information about age, gender, operator, and characteristics of nodules did not predict the outcome of nodules with Bethesda category I.

Conclusions

The adequacy of ultrasound-guided FNAs performed by head and neck surgeons is similar to that of skilled radiologists, while surgeons are more efficient than radiologists. Nondiagnostic FNA reports should not be considered benign, and repeat FNA or selective surgical treatment is recommended.

Analytic and clinical validity of thyroid nodule mutational profiling using droplet digital polymerase chain reaction

BACKGROUND

Recent guidelines for the management of thyroid nodules incorporate mutation testing as an adjunct for surgical decision-making, however current tests are costly with limited accuracy. Droplet digital PCR (ddPCR) is an ultrasensitive method of nucleic acid detection that is particularly useful for identifying gene mutations. This study aimed to assess the analytic and clinical validity of RAS and BRAF ddPCR mutational testing as a diagnostic tool for thyroid fine needle aspirate biopsy (FNAB).

METHODS

Patients with thyroid nodules meeting indication for FNAB were prospectively enrolled from March 2015 to September 2017. In addition to clinical protocol, an additional FNAB was obtained for ddPCR. Optimized ddPCR probes were used to detect mutations including HRASG12 V, HRASQ61K, HRASQ61R, NRASQ61R, NRASQ61K and BRAFV600E. The diagnostic performance of BRAF and RAS mutations was assessed individually or in combination with Bethesda classification against final surgical pathology.

RESULTS

A total of 208 patients underwent FNAB and mutational testing with the following Bethesda cytologic classification: 26.9% non-diagnostic, 55.2% benign, 5.3% FLUS/AUS, 2.9% FN/SPN, 2.4% SFM and 7.2% malignant. Adequate RNA was obtained from 91.3% (190) FNABs from which mutations were identified in 21.1% of HRAS, 11.5% of NRAS and 7.4% of BRAF. Malignant cytology or BRAFV600E was 100% specific for malignancy. Combining cytology with ddPCR BRAF600E mutations testing increased the sensitivity of Bethesda classification from 41.7 to 75%. Combined BRAFV600E and Bethesda results had a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 89.7% for thyroid malignancy in our cohort.

CONCLUSIONS

DdPCR offers a novel and ultrasensitive method of detecting RAS and BRAF mutations from thyroid FNABs. BRAFV600E mutation testing by ddPCR may serve as a useful adjunct to increase sensitivity and specificity of thyroid FNAB.