Point of care ultrasonography (POCUS) for assessment and intervention of thyroid nodules in an office setting

Introduction

Thyroid nodules are common in the general population, with an estimated prevalence of up to 50–67% in adults over the age of 50 years (1). Although vast majority of thyroid nodules are benign, 7–15% of nodules carry risks of malignancy, which necessitates further work up (2). Ultrasound is the diagnostic tool of choice for risk stratification of a thyroid nodule. Standardized guidelines such as the American Thyroid Association (ATA) risk categories and Thyroid Imaging Reporting and Data System (TI-RADS) categories developed by the American College of Radiology (ACR) are used to identify and grade sonographic high risk features that would warrant further testing by fine needle aspiration (FNA) biopsy (3). Traditionally, thyroid ultrasounds and FNA have been performed by trained radiologist or sonographer. However, with point of care ultrasound (POCUS) becoming increasingly accessible, diagnostic ultrasound use and ultrasound-guided biopsies have been adopted by many non-radiologists (4). POCUS has been shown to have good diagnostic accuracy in cardiac and musculoskeletal imaging when compared to conventional ultrasound (5,6). To date, there have been studies that demonstrated the feasibility of POCUS for assessment of thyroid nodules (4). However, further studies are needed to validate its diagnostic performance. The purpose of this study is to compare and evaluate the diagnostic performance of an office-based POCUS to hospital-based ultrasound. We hypothesized that POCUS is a non-inferior alternative to hospital-based ultrasound studies for thyroid imaging. We present this article in accordance with the STROBE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0052/rc).

Methods

This study is a retrospective cohort study performed via chart review of all patients with thyroid nodules who were referred to ENT Specialists, Inc. community-based dedicated thyroid ultrasound clinic in a large Otolaryngology practice with multiple satellite offices.

This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board at Tufts University School of Medicine (No. STUDY00006300). Informed consent was not possible for all patients, as the study only performed a retrospective chart review and many patients did not need to return to clinic for follow up appointments. All patients referred to the thyroid clinic between January 2023 and December 2024 for ultrasound-guided fine-needle biopsy were assigned American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) categories in a prospective manner by the operator immediately prior to biopsy. All diagnostic and interventional ultrasound scans were performed by an otolaryngologist (J.K.D.) with >10-year experience in these procedures. Studies and procedures were performed utilizing a GE Healthcare Versana Active portable ultrasound with a 12 Hz linear probe (12L-RS). For patients with TI-RADS scores of 1 or 2 on POCUS, FNA was not performed due to the standard of care recommendations and low risk for malignancy, and these patients were excluded from this study. The operator was blinded to the TI-RADS categories previously assigned by the hospital radiologist. Hospital assigned TI-RADS categories were subsequently obtained through a retrospective chart review of the radiologist report. The Bethesda system for Reporting Thyroid Cytopathology (BSRTC Categories) was utilized for all cytology reports. Inclusion criteria consisted of all patients that had TI-RADS categories from both the hospital radiologist and POCUS, as well as Bethesda score from biopsy of the nodule of interest (Figure 1). Surgical pathology results were not used in this study, as the goal of this study was to compare TI-RADS scores with cytology results using the Bethesda system.

Figure 1 Study inclusion tree. TI-RADS, Thyroid Imaging Reporting and Data System; US, ultrasound.

Statistical analysis

Python 3.7.4 in a Jupyter Notebook was used to conduct data analysis (7,8). SciPy, NumPy, pandas, and Matplotlib were Python packages used for data synthesis and analysis (9-11). To evaluate diagnostic performance, several metrics were examined. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the TI-RADS categories when compared with cytology as the gold standard. True positive nodules were those that had ACR TI-RADS categories of 4 or 5 and Bethesda score of III/IV with genome sequencing classifier (GSC) of suspicious, V, or VI. True negative nodules were those that had ACR TI-RADS categories of 1, 2, or 3 and had a Bethesda score of II or III/IV with GSC of benign. False positives were considered nodules that had ACR TI-RADS categories of 4 or 5 but had a Bethesda score of II or III/IV with GSC of benign. Lastly, false-negative nodules were those that had ACR TI-RADS categories of 1, 2, or 3 but had a Bethesda score of III/IV with GSC of suspicious, V, or VI.

Results

Between January 2023 and December 2024, a total of 339 nodules underwent biopsy, of which 293 had available data for both in-office and radiology TI-RADS categories (Figure 2; Table 1), and Bethesda categories of 2 through 6 (Figure 3; Tables 2,3). There were no non-diagnostic biopsy results. Two biopsy results showed atypical lymphocytes, which were excluded from the study. The POCUS TI-RADS categories yielded a sensitivity of 1.00, specificity of 0.00, PPV of 0.10, and NPV of 1.00. The hospital-based radiologist TI-RADS categories yielded a sensitivity of 0.80, specificity of 0.35, PPV of 0.12, and NPV of 0.94 (Table 4). Sensitivity was significantly higher with the POCUS TI-RADS categories (P=0.01), while specificity was significantly higher with the hospital-based radiologist TI-RADS categories (P<0.001).

Figure 2 Distribution of thyroid nodules by POCUS TI-RADS and hospital-based radiologist TI-RADS risk classifiers. POCUS, point of care ultrasound; TI-RADS, Thyroid Imaging Reporting and Data System.

Figure 3 Distribution of thyroid nodules by biopsy Bethesda score per ultrasound-guided fine-needle aspiration.

Discussion

The rate of incidental findings of thyroid nodules continues to rise over the years, partly due to increased use of various imaging modalities, including magnetic resonance imaging, computed tomography, positron emission tomography scan, and carotid doppler studies (12). Thyroid US remains the gold standard imaging modality for evaluation of thyroid nodules (13). Sonographic findings, such as microcalcifications, hypoechogenecity, and irregular margins, warrant US-guided FNA (2). Traditional workflow is long-winded, time consuming, and requires patient to navigate through multiple visits and systems. Patient is usually first seen by primary care physician (PCP) who makes referral for diagnostic thyroid US in the hospital. Patient then returns to the PCP who refers the patient to Endocrinology or Interventional Radiology if further biopsy is warranted. After undergoing US-guided FNA, patient goes back to PCP who then interprets the result and decides whether to send the patient to thyroid surgeon. Multiple appointments and hospital visits lead to increased costs and patient anxiety. Additionally, the large volume of patients that need thyroid US and FNA often puts undue burden on the radiology department in order to meet the demand. Surgeons and patients often share similar frustrations due to the delay in diagnosis and ultimately treatment.

In this study, we showed that in office POCUS for thyroid nodules had significantly higher sensitivity than in-hospital US in identifying malignant thyroid nodules. Additionally, our study shows that in office POCUS had high sensitivity with no misses on suspicious and/or malignant nodules (Bethesda III–VI), rendering it a proficient screening (rule out) test (14). It is important to note that while our in-office POCUS did not miss any malignant nodules, in-hospital US missed 6 malignant nodules. Meanwhile, both POCUS and hospital-based US demonstrated low specificity for detection of suspicious and/or malignant nodules (0% vs. 35%, respectively), which often warrants additional workup and further contributes to the high demand for US-guided FNA. These findings highlight both the demand for and feasibility of a specialized thyroid nodule clinic.

The concept of a specialized thyroid nodule clinic—or simply put “one stop shop”—is a departure from traditional algorithm, which requires patients to be seen on multiple visits prior to obtaining proper diagnosis. Example workflow of conventional workup versus workup via specialized thyroid nodule clinic is illustrated in Figure 4. Importantly, similar to our findings, many prior studies have shown that in office POCUS and US-guided FNA have comparable results and are not inferior to in hospital US. Literature has consistently shown that non-radiologists who have undergone proper accredited training to perform US-guided FNA are able to achieve results that are comparable to those of radiologists (4,15,16). Additionally, a prospective, observational study by a Spanish group further demonstrated that a specialized thyroid nodule clinic had mean estimated savings of €70,000 per year (equivalent to approximately $81,000 USD), with high rate of overall patient satisfaction secondary to reduction in waiting times and patient anxiety (17).

Figure 4 Comparison of example workflow between conventional workup versus workup through a specialized thyroid nodule clinic. FNA, fine needle aspiration; PCP, primary care physician; US, ultrasound.

The very low specificity (0%) for in-office POCUS may be artificially low and explained by inherent limitations of the study design. Bethesda scores based on FNA results were used as the gold standard for identifying if a nodule is benign or malignant. All FNAs were performed with and at the time of in-office POCUS, and need for FNA was determined based on real-time TI-RADS category calculations during the patient’s office visit. Based on TI-RADS recommendations, TI-RADS categories 1 and 2 do not need FNA (3). Therefore, patients with in-office POCUS showing TI-RADS categories 1 or 2 did not undergo FNA at the time due to low suspicion for malignancy and to follow the standard of care (TI-RADS guidelines). These patients were subsequently excluded from the study due to lack of Bethesda scores (gold standard for determining malignant vs. benign nodule). If these patients were to receive FNA, it is likely that they would fall into the true negative category for the in-office POCUS results. Thus, the specificity of in-office POCUS is likely artificially low while the sensitivity is likely artificially inflated due to exclusion of patients with TI-RADS 1 and 2. Further studies are needed to confirm adequate sensitivity and specificity for in-office POCUS. However, our study is a good proof-of-concept study that in-office POCUS is not inferior to hospital-based ultrasound as none of the malignant nodules from our cohort were missed by in-office POCUS.

Our study has several other important limitations that should be considered. First, all POCUS and US-guided FNA were performed solely by one clinician within the practice. We were unable to account for inter-rater variability within TI-RADS scoring. Additionally, the subjects in our study included only individuals who were referred to the clinic for possible biopsy. Thus, there may have been subconscious biases when scoring TI-RADS to higher risk categories, hence artificially increasing the sensitivity of POCUS. However, despite these limitations, our study showed convincing data that POCUS had comparable and non-inferior performance compared to hospital-based US systems. This study provides good evidence that incorporation of POCUS in outpatient otolaryngology office is feasible and beneficial from the perspective of both the patient and the provider as a screening (rule out) test for identifying malignant thyroid nodules.

Conclusions

In-office POCUS is a reliable diagnostic tool that offers high sensitivity in identifying malignant thyroid nodules in an in-office setting. Incorporation of POCUS in outpatient otolaryngology office may result in an expedited work-up of thyroid nodules with reduction in patient anxiety and considerable cost savings.

Acknowledgments

The authors thank the American Thyroid Association for the opportunity to present a previous version of this manuscript, titled “Point of Care Ultrasonography (POCUS) for Assessment and Intervention of Thyroid Nodules in an Office Setting”, as a poster presentation at the 95th Annual Meeting of the American Thyroid Association in 2025.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0052/rc

Data Sharing Statement: Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0052/dss

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0052/prf

Funding: This work was supported by GE Healthcare.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0052/coif). J.K.D. reports funding and equipment support (one-year loan of a GE Versana device) from GE Healthcare for data collection, analysis, medical writing, and article processing charges. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board at Tufts University School of Medicine (No. STUDY00006300). Informed consent was not possible for all patients, as the study only performed a retrospective chart review and many patients did not need to return to clinic for follow up appointments.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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