Knot-and-ear sign: a pathognomonic ultrasonographic feature of suture granuloma after thyroid surgery

PURPOSE

This study investigated the clinical and ultrasonographic (US) findings of suture granulomas and recurrent tumors, and aimed to identify specific characteristics of suture granulomas through an experimental study.

METHODS

This retrospective study included 20 pathologically confirmed suture granulomas and 40 recurrent tumors between January 2010 and December 2020. The clinical findings included suture material, surgery, and initial TNM stage. The US findings included shape, size, margin, echogenicity, heterogeneity, vascularity, and internal echogenic foci. The distribution, paired appearance, and "knot-and-ear" appearance of internal echogenic foci were assessed. An experiment using pork meat investigated the US configuration of suture knots.

RESULTS

Eighteen patients with 20 suture granulomas (15 women; mean age, 52±13 years) and 37 patients with 40 recurrent tumors (24 women; 54±18 years) were included. Patients with suture granulomas exhibited earlier initial T and N stages than those with recurrent tumors. The knot-and-ear appearance, defined as an echogenic dot accompanied by two adjacent echogenic dots or lines based on experimental findings, was observed in 50% of suture granulomas, but not in recurrent tumors (P<0.001). Central internal echogenic foci (68.8%, P=0.023) and paired appearance (75.0%, P<0.001) were more frequent in suture granulomas. During follow-up, 94.1% of suture granulomas shrunk.

CONCLUSION

The knot-and-ear appearance is a potential pathognomonic finding of suture granuloma, and central internal echogenic foci with paired appearance were typical US features. Clinically, suture granulomas showed early T and N stages and size reduction during follow-up. Understanding these features can prevent unnecessary biopsy or diagnostic surgery.

The Diagnostic Role of Repeated Biopsy of Thyroid Nodules with Atypia of Undetermined Significance with Architectural Atypia on Core-Needle Biopsy

Background

We aimed to evaluate the utility of repeat biopsy of thyroid nodules classified as atypia of undetermined significance with architectural atypia (IIIB) on core-needle biopsy (CNB).

Methods

This retrospective study evaluated patients with thyroid nodules categorized as IIIB on CNB between 2013 and 2015. Demographic characteristics, subsequent biopsy results, and ultrasound (US) images were evaluated. The malignancy rates of nodules according to number of CNBs and the number of IIIB diagnoses was compared. Demographic and US features were evaluated to determine factors predictive of malignancy.

Results

Of 1,003 IIIB nodules on CNB, the final diagnosis was determined for 328 (32.7%) nodules, with 121 of them confirmed as malignant, resulting in a malignancy rate of 36.9% (95% confidence interval, 31.7% to 42.1%). Repeat CNB was performed in 248 nodules (24.7%), with 75 (30.2%), 131 (52.8%), 13 (5.2%), 26 (10.5%), one (0.4%), and two (0.8%) reclassified into categories II, IIIB, IIIA, IV, V, and VI, respectively. Malignancy rates were not significantly affected by the number of CNBs (P=0.291) or the number of IIIB diagnoses (P=0.473). None of the nodules confirmed as category II on repeat CNB was malignant. US features significantly associated with malignancy (P<0.003) included solid composition, irregular margins, microcalcifications, and high suspicion on the US risk stratification system.

Conclusion

Repeat biopsy of nodules diagnosed with IIIB on CNB did not increase the detection of malignancy but can potentially reduce unnecessary surgery. Repeat biopsy should be performed selectively, with US features guiding the choice between repeat biopsy and diagnostic surgery.

Impact of Additional Preoperative Computed Tomography Imaging on Staging, Surgery, and Postsurgical Survival in Patients With Papillary Thyroid Carcinoma

OBJECTIVE

We investigated the impacts of computed tomography (CT) added to ultrasound (US) for preoperative evaluation of patients with papillary thyroid carcinoma (PTC) on staging, surgical extent, and postsurgical survival.

MATERIALS AND METHODS

Consecutive patients who underwent surgery for PTC between January 2015 and December 2015 were retrospectively identified. Of them, 584 had undergone preoperative additional thyroid CT imaging (CT + US group), and 859 had not (US group). Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were used to adjust for 14 variables and balance the two groups. Changes in nodal staging and surgical extent caused by CT were recorded. The recurrence-free survival and distant metastasis-free survival after surgery were compared between the two groups.

RESULTS

In the CT + US group, discordant nodal staging results between CT and US were observed in 94 of 584 patients (16.1%). Of them, CT accurately diagnosed nodal staging in 54 patients (57.4%), while the US provided incorrect nodal staging. Ten patients (1.7%) had a change in the extent of surgery based on CT findings. Postsurgical recurrence developed in 3.6% (31 of 859) of the CT + US group and 2.9% (17 of 584) of the US group during the median follow-up of 59 months. After adjustment using IPTW (580 vs. 861 patients), the CT + US group showed significantly higher recurrence-free survival rates than the US group (hazard ratio [HR], 0.52 [95% confidence interval {CI}, 0.29-0.96]; P = 0.037). PSM analysis (535 patients in each group) showed similar HR without statistical significance (HR, 0.60 [95% CI, 0.31-1.17]; P = 0.134). For distant metastasis-free survival, HRs after IPTW and PSM were 0.75 (95% CI, 0.17-3.36; P = 0.71) and 0.87 (95% CI, 0.20-3.80; P = 0.851), respectively.

CONCLUSION

The addition of CT imaging for preoperative evaluation changed nodal staging and surgical extent and might improve recurrence-free survival in patients with PTC.

Imaging findings of granular cell tumours of the head and neck

AIM

To review the imaging characteristics of granular cell tumours in the head and neck and assess their associations with pathological findings.

MATERIALS AND METHODS

Eleven patients (10 [91%] women, mean age 43 years) with histopathologically confirmed granular cell tumours were included in this study. Preoperative imaging studies were performed, including computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound. The location of the tumours, their imaging features, and histopathological findings were analysed.

RESULTS

Among the 11 granular cell tumours, four (36%), three (27%), and two (18%) tumours were found in the submucosal layer, subcutaneous layer, and intramuscular area, respectively. On CT, all tumours exhibited homogeneous iso-attenuating enhancement compared with adjacent muscle, and nine out of the 11 tumours (81%) demonstrated well-defined margins. On T2-weighted imaging (T2WI), four out of five tumours (80%) demonstrated iso-signal intensity compared with adjacent muscles, and four tumours (80%) exhibited homogeneous signal intensity. The apparent diffusion coefficient (ADC) values ranged from 0.68-0.81 × 10-3 mm2/s. Histopathological examination revealed densely packed tumour cells with variable amounts of fibrous stroma.

CONCLUSION

Granular cell tumours were characterised by well-defined and iso-signals on T2WI and low mean ADC values, and were predominantly located in the submucosal, subcutaneous, or intramuscular areas in middle-aged women. The characteristic locations, demographic characteristics, and imaging findings can help to differentiate granular cell tumours from other soft-tissue tumours in the head and neck.

Validation of CT-Based Risk Stratification System for Lymph Node Metastasis in Patients With Thyroid Cancer

OBJECTIVE

To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines.

MATERIALS AND METHODS

A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests.

RESULTS

The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS.

CONCLUSION

Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

Phase II study of a trastuzumab biosimilar in combination with paclitaxel for HER2-positive recurrent or metastatic urothelial carcinoma: KCSG GU18-18

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is a widely explored therapeutic target in solid tumors. We evaluated the efficacy and safety of trastuzumab-pkrb, a biosimilar of trastuzumab, in combination with paclitaxel, in HER2-positive recurrent or metastatic urothelial carcinoma (UC).

PATIENTS AND METHODS

We enrolled 27 patients; they were administered a loading dose of 8 mg/kg trastuzumab-pkrb on day 1, followed by 6 mg/kg and 175 mg/m2 paclitaxel on day 1 every 3 weeks, intravenously. All patients received six cycles of the combination treatment and continued to receive trastuzumab-pkrb maintenance until disease progression, unacceptable toxicity, or for up to 2 years. HER2 positivity (based on immunohistochemistry analysis) was determined according to the 2013 American Society of Clinical Oncology /College of American Pathologists HER2 testing guidelines. The primary endpoint was objective response rate (ORR); the secondary endpoints were overall survival (OS), progression-free survival (PFS), and safety.

RESULTS

Twenty-six patients were evaluated via primary endpoint analysis. The ORR was 48.1% (1 complete and 12 partial responses) and the duration of response was 6.9 months [95% confidence interval (CI) 4.4-9.3 months]. With a median follow-up of 10.5 months, the median PFS and OS were 8.4 months (95% CI 6.2-8.8 months) and 13.5 months (95% CI 9.8 months-not reached), respectively. The most common treatment-related adverse event (TRAE) of any grade was peripheral neuropathy (88.9%). The most common grade 3/4 TRAEs were neutropenia (25.9%), thrombocytopenia (7.4%), and anemia (7.4%).

CONCLUSIONS

Trastuzumab-pkrb plus paclitaxel demonstrates promising efficacy with manageable toxicity profiles in patients with HER2-positive recurrent or metastatic UC.

Image findings of anti-neutrophil cytoplasmic antibody-associated vasculitis involving the skull base

AIM

To investigate computed tomography (CT) and magnetic resonance imaging (MRI) features of skull bases involving anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV).

MATERIALS AND METHODS

A retrospective review was undertaken to identify an institutional historical cohort of 17 patients with confirmed AAV who underwent CT or MRI and had skull base involvement between 2002 and 2021. Two radiologists reviewed the extent and features of the lesions, bone changes, and other MRI findings.

RESULTS

A total of 17 patients (12 men; mean age ± standard deviation, 46.5 ± 17.1 years) were selected. AAV presented as infiltrative lesions with involvement at various sites. Most cases involved the paranasal sinuses (PNS; 88%, 15/17), nasopharynx (88%, 15/17), pterygopalatine fossa (82%, 14/17), and parapharyngeal space (82%, 14/17), frequently accompanied by mucosal irregularity of the PNS and nasopharynx (71%, 12/17). Central skull base and temporal bone involvement were seen in 53% (9/17) and 38% (6/16) of cases, respectively. On T1-weighted imaging (WI) and T2WI MRI, all lesions (15/15) showed predominant signal iso-intensity to grey matter.

CONCLUSIONS

Although radiological findings of AAV are non-specific and skull base involvement is less common, AAV may be considered if infiltrative lesions predominantly involving the PNS, nasopharynx, pterygopalatine fossa, and parapharyngeal space with combined bone changes of skull base are seen.

Fixed Drug Eruption in a Patient Taking Valacyclovir without Cross-Reactivity to Acyclovir

Fixed drug eruption (FDE) is a well-defined hyperpigmented patch that recurs in a fixed location each time a particular drug is taken. Common causative agents of FDE are non-steroidal anti-inflammatory drugs, non-narcotic analgesics, sedatives, anticonvulsants, sulfonamides, and tetracycline. We report a 33-year-old male who presented with a recurrent, localized, brownish-to-erythematous macule and papules on the peri-philtrum area two hours after taking valacyclovir. Three episodes of valacyclovir ingestion for treatment of Herpes simplex virus infection provoked a similar skin rash at the same site. Histopathology results showed vacuolar degeneration in the basal layer of the epidermis, pigmentary incontinence, and perivascular inflammatory cell infiltration in the papillary dermis. Although patch test and skin prick test showed negative responses to acyclovir and valacyclovir, an intradermal test showed a positive reaction only to valacyclovir. The oral provocation test to acyclovir and valacyclovir showed a positive reaction only to valacyclovir. Through drug history, histopathological examination, patch test, intradermal test, and oral provocation test, we established a final diagnosis of FDE due to valacyclovir without cross-reactivity to acyclovir. To find alternative therapeutic drugs, we suggest diagnostic tests with not only the suspected drugs, but also other drugs in the same class.

Radiofrequency ablation of benign thyroid nodules: the value of anterolateral hydrodissection

PURPOSE

This study aimed to evaluate the technical feasibility, efficacy, and safety of anterolateral hydrodissection (ALHD) in radiofrequency ablation (RFA) for benign thyroid nodules.

METHODS

Between November 2019 and April 2020, 39 patients underwent 41 sessions of RFA with the ALHD technique to treat benign thyroid nodules. ALHD was performed with cold (0°C-4°C) 5% dextrose solution during RFA to minimize pain and secure sufficient safety margins from critical neck structures. The initial ablation ratio (IAR) was measured to assess the technique's efficiency. Ultrasound examinations, symptoms, and cosmetic scores were evaluated pre-procedure and at 6 and 12 months post-procedure. Procedure-related pain during RFA and complications were recorded.

RESULTS

The mean index nodule volume was 20.5±21.6 mL. ALHD was technically feasible in all patients. The mean IAR was 90.7%±8.3%, and significant reductions in mean nodule volume were noted at 6- and 12-month follow-ups (P<0.001, 63.9%±19.0%, and 76.3%±18.9%, respectively). Symptom and cosmetic scores showed significant improvements at 6- and 12-month follow-ups (P<0.001). Pain during the procedure was well-controlled with ALHD in all patients. After the initial use of 5-10 mL of lidocaine at the start of the procedure, no further lidocaine injection was given to any patient. Transient voice change was observed in one patient, but the patient recovered spontaneously within 30 minutes.

CONCLUSION

The ALHD technique was technically feasible and effective in all patients, achieving a mean IAR of 90.7%. The ALHD technique also had a pain-relieving effect, resulting in only low amounts of lidocaine administration being required during the procedure.

Swallowing analysis in hemi-tongue reconstruction using motor-innervated free flaps: A cine-magnetic resonance imaging study

BACKGROUND

This study aimed to explore the outcomes of motor-innervated free flaps in hemi-tongue reconstruction by assessing the tongue mobility through midsagittal images from cine-magnetic resonance imaging.

METHODS

In this retrospective study, 47 patients who underwent tongue reconstruction following hemi-glossectomy and 10 control subjects without any surgical history were included. Patients were classified into two groups: the motor and no-motor innervation group. Various spatial parameters related to tongue mobility that were acquired from midsagittal sections were compared during consecutive swallowing phases.

RESULTS

Overall, the motor group showed improved functional swallowing scale compared with the no-motor group. In case of tongue base resection, the motor group showed improved mobility of the tongue base during pharyngeal phase, whereas the no-motor group showed increased laryngeal elevation for compensatory movement.

CONCLUSION

The tongue reconstruction with motor-innervated free flaps may facilitate swallowing capacity in patients with a hemi-tongue defect combined with tongue base resection.

Diagnosis of parathyroid incidentaloma detected on thyroid ultrasonography: the role of fine-needle aspiration cytology and washout parathyroid hormone measurements

PURPOSE

The aim of this study was to assess the diagnostic role of fine-needle aspiration cytology (FNAC) and analyze factors associated with false-negative FNAC results in patients with parathyroid incidentaloma who were referred for ultrasonography (US)-guided fine-needle aspiration (FNA) of thyroid nodules.

METHODS

In this study, 121 patients with suspected parathyroid lesions were enrolled. The patients underwent US-guided FNAC with measurements of washout parathyroid hormone (PTH) between January 2015 and May 2020. The diagnostic performance of FNAC for the diagnosis of parathyroid lesions was assessed using surgical results and elevated washout PTH as a reference standard. The clinical and radiologic features associated with false-negative results on FNAC for the diagnosis of parathyroid lesions were evaluated.

RESULTS

Among the 121 nodules assessed, 38 were parathyroid lesions (31.4%), and 83 were non-parathyroid lesions (68.6%). The diagnostic performance of FNAC for parathyroid incidentaloma showed a sensitivity of 31.6% (12/38), specificity of 100% (83/83), positive predictive values of 100% (12/12), negative predictive values of 76.1% (83/109), and accuracy of 78.5% (95/121). The FNAC results of non-parathyroid lesions included thyroid nodules, lymph nodes, neurogenic tumors, and fat tissue. True-positive results on FNAC were significantly associated with performing FNA twice (58.3% vs. 23.1%, P=0.043).

CONCLUSION

Considering the low sensitivity of FNAC, measuring washout PTH in addition to FNAC may help accurately diagnose parathyroid incidentaloma on thyroid US. Further, the falsenegative rate for FNAC can be reduced by obtaining two or more FNA samples.

Development and Validation of a Model Using Radiomics Features from an Apparent Diffusion Coefficient Map to Diagnose Local Tumor Recurrence in Patients Treated for Head and Neck Squamous Cell Carcinoma

OBJECTIVE

To develop and validate a model using radiomics features from apparent diffusion coefficient (ADC) map to diagnose local tumor recurrence in head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

This retrospective study included 285 patients (mean age ± standard deviation, 62 ± 12 years; 220 male, 77.2%), including 215 for training (n = 161) and internal validation (n = 54) and 70 others for external validation, with newly developed contrast-enhancing lesions at the primary cancer site on the surveillance MRI following definitive treatment of HNSCC between January 2014 and October 2019. Of the 215 and 70 patients, 127 and 34, respectively, had local tumor recurrence. Radiomics models using radiomics scores were created separately for T2-weighted imaging (T2WI), contrast-enhanced T1-weighted imaging (CE-T1WI), and ADC maps using non-zero coefficients from the least absolute shrinkage and selection operator in the training set. Receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of each radiomics score and known clinical parameter (age, sex, and clinical stage) in the internal and external validation sets.

RESULTS

Five radiomics features from T2WI, six from CE-T1WI, and nine from ADC maps were selected and used to develop the respective radiomics models. The area under ROC curve (AUROC) of ADC radiomics score was 0.76 (95% confidence interval [CI], 0.62-0.89) and 0.77 (95% CI, 0.65-0.88) in the internal and external validation sets, respectively. These were significantly higher than the AUROC values of T2WI (0.53 [95% CI, 0.40-0.67], p = 0.006), CE-T1WI (0.53 [95% CI, 0.40-0.67], p = 0.012), and clinical parameters (0.53 [95% CI, 0.39-0.67], p = 0.021) in the external validation set.

CONCLUSION

The radiomics model using ADC maps exhibited higher diagnostic performance than those of the radiomics models using T2WI or CE-T1WI and clinical parameters in the diagnosis of local tumor recurrence in HNSCC following definitive treatment.

Sonographic Diagnosis of Cervical Lymph Node Metastasis in Patients with Thyroid Cancer and Comparison of European and Korean Guidelines for Stratifying the Risk of Malignant Lymph Node

OBJECTIVE

To evaluate the ultrasonography (US) features for diagnosing metastasis in cervical lymph nodes (LNs) in patients with thyroid cancer and compare the US classification of risk of LN metastasis between European and Korean guidelines.

MATERIALS AND METHODS

From January 2014 to December 2018, US-guided fine-needle aspiration was performed on 836 LNs from 714 patients for the preoperative nodal staging of thyroid cancer. The US features of LNs were retrospectively reviewed for the following features: size, presence of hilum, margin, orientation, cystic change, punctate echogenic foci (PEF), large echogenic foci, eccentric cortical thickening, abnormal vascularity, and cortical hyperechogenicity. A multiple logistic regression analysis was performed to identify the independent US features for the diagnosis of metastatic LNs. The diagnostic performance of independent US features was subsequently evaluated. LNs were categorized according to the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and European Thyroid Association (ETA) guidelines, and the correlation between the two sets of classifications was assessed.

RESULTS

Absence of the hilum, presence of cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features of metastatic LNs. Cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity showed high specificity (86.8%-99.6%). The absence of the hilum had the highest sensitivity yet low specificity (66.4%). When LNs were classified according to the ETA guidelines and K-TIRADS, they yielded similar categorizations of malignancy risks and were strongly correlated (Spearman coefficient, 0.9766 [95% confidence interval, 0.973-0.979]). According to the ETA guidelines, 9.8% (82/836) of LNs were classified as "not specified."

CONCLUSION

Absence of hilum, cystic changes, PEF, abnormal vascularity, and cortical hyperechogenicity were independent US features suggestive of metastatic LNs in thyroid cancer. Both K-TIRADS and the ETA guidelines provided similar risk stratification for metastatic LNs with a high correlation; however, the ETA guidelines failed to classify 9.8% of LNs into a specific risk stratum. These results may provide a basis for revising LN classification in future guidelines.

Augmented risk of ischemic stroke in hypertrophic cardiomyopathy patients without documented atrial fibrillation

Background

Ischemic stroke is a common complication in patients with hypertrophic cardiomyopathy (HCM) (1). Although atrial fibrillation (AF) is a well-established risk factor for ischemic stroke in HCM, the risk of ischemic stroke in patients with HCM without documented AF is less recognized (1, 2). This study aimed to determine the risk of ischemic stroke and identify its risk factors in patients with HCM without documented AF.

Methods

This nationwide population-based cohort study used the Korean National Health Insurance database. After excluding patients with a prior history of AF, thromboembolic events, cancer, or the use of anticoagulants, we identified 8,328 HCM patients without documented AF and 1:2 propensity score-matched 16,656 non-HCM controls. The clinical outcome was an incident ischemic stroke.

Results

During a mean follow-up of approximately 6 years, ischemic stroke occurred in 328/8,328 (3.9%) patients with HCM and 443/16,656 (2.7%) controls. Among individuals who developed ischemic stroke, the proportion of AF concomitantly detected accounted for 26.5% (87/328) and 5.8% (26/443) in the HCM and control groups, respectively. The overall incidence of ischemic stroke was 0.716/100 person-years in the HCM group, which was significantly higher than that in the control group (0.44/100 person-years) (HR 1.643; 95% CI, 1.424–1.895; P&lt;0.001, Figure 1). The subgroup analysis according to age, sex, and comorbidities (chronic heart failure, hypertension, dyslipidemia, and vascular disease) consistently demonstrated a higher risk of ischemic stroke in the HCM group (P for interaction &gt;0.05). In the HCM group, age ≥65 years (adjusted hazard ratio [HR] 2.741; 95% confidence interval [CI], 2.156–3.486; P&lt;0.001) and chronic heart failure (adjusted HR 1.748; 95% CI, 1.101–2.745; P=0.018) were independent risk factors for ischemic stroke. Overall incidence was 1.360/100 in patients with HCM aged ≥65 and 2.315/100 person-years years in those with chronic heart failure, respectively. Also, compared to controls aged &lt;65 years and without CHF, adjusted HR for ischemic stroke was 4.756 (95% CI 3.807–5.867) in patients with HCM aged ≥65 years and 2.539 (95% CI 1.638–3.936) in those with CHF, respectively (Figure 2).

Conclusions

Patients with HCM without documented AF are at a higher risk of ischemic stroke than the propensity score-matched general population. Age ≥65 years and chronic heart failure are two strong independent risk factors for ischemic stroke in this population.

Funding Acknowledgement

Type of funding sources: None.

Sodium-glucose co-transporter-2 inhibitors after acute myocardial infarction in type 2 diabetes patients: a population-based investigation from South Korea

Background

Whether the early use of sodium-glucose co-transporter-2 (SGLT2) inhibitors has cardioprotective effects following acute myocardial infarction (AMI) is unknown.

Purpose

We aimed to evaluate the association between the early initiation of SGLT2 inhibitors and cardiac event rates in diabetes patients with AMI undergoing percutaneous coronary intervention (PCI).

Methods

Based on the National Health Insurance claims data in South Korea, patients aged 18 years or older who had undergone PCI for the diagnosis of AMI between 2014 and 2018 were analyzed. Patients treated with SGLT2 inhibitors or other glucose-lowering drugs were matched based on a propensity score. The primary endpoint was a composite of all-cause mortality and hospitalizations for heart failure (HF). Major adverse cardiac events (MACE; a composite of all-cause death, non-fatal MI, and ischemic stroke) were compared as the secondary endpoint.

Results

After 1:2 propensity score matching, a total of 26,814 patients were assigned to the SGLT2 inhibitors group (938 patients) and the no use of SGLT2 inhibitors group (1,876 patients), respectively. During a median follow-up of 2.1 years, compared to no use of SGLT2 inhibitors, the early use of SGLT2 inhibitors was associated with lower risks of both the primary endpoint (9.8% vs. 13.9%, adjusted hazard ratio [HR] = 0.68, 95% confidence interval [CI]: 0.54 to 0.87, p=0.002) and secondary endpoint (9.1% vs. 11.6%, adjusted HR = 0.77, 95% CI: 0.60 to 0.99, p=0.04) (Figure 1). All-cause mortality and hospitalizations for HF were significantly lower in the early use of SLGT2 inhibitors group (adjusted HR = 0.55; 95% CI: 0.37 to 0.80; p=0.002; and HR = 0.74; 95% CI: 0.56 to 0.98; p=0.03, respectively). The incidence of non-fatal MI and ischemic stroke were not statistically different (Figure 2).

Conclusions

The early use of SGLT2 inhibitors in diabetes patients treated with PCI for AMI was associated with a significantly lower risk of cardiovascular events including all-cause mortality, hospitalizations for HF, and MACE. Our results suggest that the use of SGLT2 inhibitors could expand to the acute phase of AMI survivors with diabetes to reduce mortality and the subsequent development of congestive HF and ischemic events.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): This work was partly supported by the Research Institute of Medical Science, The Catholic University of Korea, Eunpyeong St. Mary's Hospital, Seoul, Republic of Korea.

Clinical and Radiological Features of Diffuse Lacrimal Gland Enlargement: Comparisons among Various Etiologies in 91 Biopsy-Confirmed Patients

Objective

To compare the clinical and radiological features of various etiologies of chronic diffuse lacrimal gland enlargement.

Materials and Methods

We retrospectively reviewed 91 consecutive patients who underwent surgical biopsy for chronic diffuse lacrimal gland enlargement and were diagnosed with non-specific dacryoadenitis (DA) (n = 42), immunoglobulin G4-related dacryoadenitis (IgG4-RD) (n = 33), and lymphoma (n = 16). Data on patient demographics, clinical presentation, and CT imaging findings (n = 73) and MRI (n = 43) were collected. The following radiologic features of lacrimal gland enlargement were evaluated: size, unilaterality, wedge sign, angle with the orbital wall, heterogeneity, signal intensity, degree of enhancement, patterns of dynamic contrast-enhanced, and apparent diffusion coefficient value. Radiological features outside the lacrimal glands, such as extra-lacrimal orbital involvement and extra-orbital head and neck involvement, were also evaluated. The clinical and radiological findings were compared among the three diseases.

Results

Compared to the DA and IgG4-RD groups, the lymphoma group was significantly older (mean 59.9 vs. 46.0 and 49.4 years, respectively; p = 0.001) and had a higher frequency of unilateral involvement (62.5% vs. 31.0% and 15.2%, respectively; p = 0.004). Compared to the IgG4-RD and lymphoma groups, the DA group had significantly smaller lacrimal glands (2.3 vs. 2.8 and 3.3 cm, respectively; p < 0.001) and a lower proportion of cases with a wedge sign (54.8% vs. 84.8% and 87.5%, respectively; p = 0.005). The IgG4-RD group showed more frequent involvement of the extra-orbital head and neck structures, including the infraorbital nerve (36.4%), paranasal sinus (72.7%), and salivary gland (58.6%) compared to the DA and lymphoma groups (4.8%–28.6%) (all p < 0.005).

Conclusion

Patient age, unilaterality, lacrimal gland size, wedge sign, and extra-orbital head and neck involvement differed significantly different between lymphoma, DA, and IgG4-RD. Our results will be useful for the differential diagnosis and proper management of chronic lacrimal gland enlargement.

Diagnostic Performance of Core Needle Biopsy for Characterizing Thyroidectomy Bed Lesions

Objective

Thyroidectomy bed lesions frequently show suspicious ultrasound (US) features after thyroid surgery. Fine-needle aspiration (FNA) may not provide definitive pathological information about the lesions. Although core-needle biopsy (CNB) has excellent diagnostic performance in characterizing suspicious thyroid nodules, no published studies have evaluated the performance of CNB specifically for thyroidectomy bed lesions. Therefore, we aimed to evaluate the diagnostic performance and safety of CNB for characterizing thyroidectomy bed lesions.

Materials and Methods

A total of 124 thyroidectomy bed lesions in 113 patients (79 female and 34 male; age, 23–85 years) who underwent US-guided CNB between December 2008 and December 2020 were included. We reviewed the US imaging features of the target lesions and the histories of previous biopsies. The pathologic results, diagnostic performance for malignancy, and complications of CNB were analyzed.

Results

All samples (100%) obtained by CNB were adequate for pathological analysis. Pathological analysis revealed inconclusive results in two lesions (1.6%). According to the reference standard, 50 lesions were ultimately malignant (40.3%), and 72 were benign (58.1%), excluding the two inconclusive lesions. The performance of CNB for diagnosing malignant thyroidectomy bed lesions in the 122 lesions had a sensitivity of 98.0% (49/50), a specificity of 100% (72/72), positive predictive value of 100% (49/49), and negative predictive value of 98.6% (72/73). Eleven lesions were referred for CNB after prior inconclusive FNA results in thyroidectomy bed lesions, for all of which CNB yielded correct conclusive pathologic diagnoses. According to the pathological analysis of CNB, there were various benign lesions (58.9%, 73/124) besides recurrence, including benign postoperative lesions other than suture granuloma (32.3%, 40/124), suture granuloma (15.3%, 19/124), remnant thyroid tissue (5.6%, 7/124), parathyroid lesions (4%, 5/124), and abscesses (1.6%, 2/124). No major or minor complications were associated with the CNB procedure.

Conclusion

US-guided CNB is accurate and safe for characterizing thyroidectomy bed lesions.

Diagnostic performance of the 2021 Korean thyroid imaging reporting and data system in pediatric thyroid nodules

OBJECTIVES

To evaluate the diagnostic performance of 2021 K-TIRADS biopsy criteria for detecting malignant thyroid nodules in a pediatric population, making comparisons with 2016 K-TIRADS.

METHODS

This retrospective study included pediatric patients with histopathologically confirmed diagnoses. The diagnostic performance of 2021 K-TIRADS was compared with that of 2016 K-TIRADS. Simulation studies were performed by changing biopsy cut-off sizes for K-TIRADS 5 to 1.0 cm (K-TIRADS_5-1.0cm) and 0.5 cm (K-TIRADS_5-0.5cm), and for K-TIRADS 4 to 1.0 cm (K-TIRADS_4-1.0cm) and 1.0-1.5 cm (K-TIRADS_4-1.0~1.5cm). Subgroup analysis was performed in small (< 1.5 cm) and large nodules (≥ 1.5 cm).

RESULTS

Two hundred seventy-seven thyroid nodules (54.9% malignant) from 221 pediatric patients were analyzed. All simulated 2021 K-TIRADS showed higher accuracy than 2016 K-TIRADS. Compared with 2021 K-TIRADS_5-1.0cm, 2021 K-TIRADS_5-0.5cm showed lower specificity (51.6% vs. 47.9%; p = 0.004) but higher sensitivity (77.2% vs. 90.3%; p < 0.001) and accuracy (62.7% vs. 68.9%; p < 0.001). Compared with 2021 K-TIRADS_4-1.0cm, 2021 K-TIRADS_4-1.0~1.5cm showed higher specificity (44.9% vs. 47.9%; p = 0.018) without significant difference in other diagnostic measures. Compared with 2016 K-TIRADS, 2021 K-TIRADS (biopsy cut-offs, 0.5 cm for K-TIRADS 5; 1.0-1.5 cm for K-TIRADS 4) showed higher sensitivity (34.0% vs. 67.3%; p < 0.001) while maintaining specificity (89.4% vs. 88.2%; p = 0.790) in small nodules, and higher specificity (5.9% vs. 25.4%; p < 0.001) while maintaining sensitivity (100% vs. 98.7%; p = 0.132) in large nodules.

CONCLUSIONS

In pediatric patients, 2021 K-TIRADS showed superior diagnostic accuracy to 2016 K-TIRADS, especially with a biopsy cut-off of 0.5 cm for K-TIRADS 5 and 1.0-1.5 cm for K-TIRADS 4.

KEY POINTS

• All simulated 2021 K-TIRADS showed higher accuracy than 2016 K-TIRADS. • 2021 K-TIRADS with cut-off size for K-TIRADS 5 of 0.5 cm showed lower specificity but higher sensitivity and accuracy than that of 1.0 cm. • Compared with 2016 K-TIRADS, 2021 K-TIRADS (biopsy cut-offs, 0.5 cm for K-TIRADS 5; 1.0-1.5 cm for K-TIRADS 4) showed higher sensitivity while maintaining specificity in small nodules, and higher specificity while maintaining sensitivity in large nodules.

Diagnostic Performance of Five Adult-based US Risk Stratification Systems in Pediatric Thyroid Nodules

Background The validation of adult-based US risk stratification systems (RSSs) in the discrimination of malignant thyroid nodules in a pediatric population remains lacking. Purpose To estimate and compare the diagnostic performance of pediatric US RSSs based on five adult-based RSSs in the discrimination of malignant thyroid nodules in a pediatric sample. Materials and methods Pediatric patients (age ≤18 years) with histopathologically confirmed US-detected thyroid nodules at a tertiary referral hospital between January 2000 and April 2020 were analyzed retrospectively. The diagnostic performance of US-based fine-needle aspiration biopsy (FNAB) criteria in thyroid cancer detection was estimated. The following sensitivity analyses were performed: (a) scenario 1: nodules smaller than 1 cm, with the highest category additionally biopsied; (b) scenario 2, application of American College of Radiology Thyroid Imaging Reporting and Data System nodule size cutoffs to other RSSs; (c) scenario 3, scenarios 1 and 2 together. Generalized estimating equations (GEEs) were used for estimation. Results A total of 277 thyroid nodules in 221 pediatric patients (median age, 16 years [interquartile range {IQR}, 13-17]; 172 female; 152 of 277 patients [55%] malignant) were analyzed. The GEE-estimated sensitivity and specificity ranged from 70% to 78% (104 to 119 of 152 patients, based on each reader's interpretation) and from 42% to 78% (49 of 124 patients to 103 of 125 patients). In scenario 1, the missed malignancy rate was reduced from 32%-38% (41 of 134 patients to 34 of 83 patients) to 15%-21% (eight of 59 patients to 28 of 127 patients). In scenario 2, the unnecessary biopsy rate was reduced from 35%-39% (60 of 176 patients to 68 of 175 patients) to 20%-34% (18 of 109 patients to 62 of 179 patients). The highest accuracy was noted in scenario 3 (range, 71%-81%; 199 of 277 patients to 216 of 262 patients). Conclusion The diagnostic performances of the fine-needle aspiration biopsy criteria of five adult-based risk stratification systems were acceptable in the pediatric population and were improved by applying the American College of Radiology Thyroid Imaging Reporting and Data System size cutoff for nodules 1 cm or larger and allowing biopsy of the highest category nodules smaller than 1 cm. © RSNA, 2022 Online supplemental material is available for this article.

Trends in body mass index changes among Korean adolescents between 2005-2020, including the COVID-19 pandemic period: a national representative survey of one million adolescents

OBJECTIVE

The impact of the coronavirus disease 2019 (COVID-19) pandemic on weight gain in children and adolescents remains unknown. We aimed to identify an estimated 15-year trend in mean body mass index (BMI) changes and prevalence of obesity and overweight among Korean adolescents from 2005 to 2020, including the period of the COVID-19 pandemic.

PATIENTS AND METHODS

We analyzed data taken from a nationwide survey (Korea Youth Risk Behavior Survey), between 2005 and 2020. Representative samples of one million Korean adolescents aged 13-18 years (n=1,057,885) were examined. The 15-year trends in mean BMI and proportion of obesity or overweight, and the changes due to the COVID-19 pandemic were analyzed.

RESULTS

The data of 1,057,885 Korean adolescents were analyzed (mean age: 14.98 years; females, 48.4%). The estimated weighted mean BMI was 20.5 kg/m2 [95% confidence interval (CI), 20.4-20.5] from 2005 to 2008 and 21.5 kg/m2 (95% CI, 21.4-21.6) in 2020 (during the COVID-19 pandemic). Although the 15-year trend of mean BMI gradually increased, the change in mean BMI before and during the pandemic significantly lessened (βdiff, -0.027; 95% CI, -0.028 to -0.026). The 15-year (2005-2020) trend changes in the prevalence of obesity and overweight were similar (obesity prevalence from 2005-2008, 3.2%; 95% CI, 3.1-3.3 vs. obesity prevalence in 2020, 8.6%; 95% CI, 8.2-9.0; βdiff, -0.309; 95% CI, -0.330 to -0.288).

CONCLUSIONS

The 15-year trend of overall mean BMI and obesity and overweight prevalence demonstrated a significant increase; however, its slope decreased during the pandemic. These landmark results suggest the need for the development of precise strategies to prevent pediatric obesity and overweight during the COVID-19 pandemic.

Ethanol ablation for the treatment of thyroglossal duct cysts: follow-up results for longer than 2 years

OBJECTIVES

To evaluate the long-term efficacy and safety of ethanol ablation (EA) for the treatment of thyroglossal duct cysts (TGDCs).

METHODS

This retrospective study included 81 consecutive patients diagnosed with and treated for symptomatic TGDCs at two institutions between Jan 2008 and Oct 2018. Preprocedural evaluation included US assessment with calculation of the TGDC volume. EA was performed under US guidance using 99% ethanol. Post-treatment follow-up was scheduled within 3 months, 6 months, and then annually. Immediate success was defined as a volume reduction ratio (VRR; ratio of the volume difference after EA to the initial TGDC volume) > 50% within 3 months. Long-term success was defined as VRR > 50% or resolution or improvement of cosmetic problems and symptoms without recurrence at last follow-up.

RESULTS

Seventy-seven patients underwent EA, and outcomes were assessed in 68 patients with available follow-up data. The immediate success rate of the first EA was 81% (55/68), with a mean VRR within 3 months of 73% ± 31%. One patient (1.5%, 1/68) developed wound inflammation after the first EA. Forty-two patients were followed up for longer than 2 years. For the median follow-up of 69 months (range, 24-131 months), the long-term success rate was 83% (35/42), with a mean VRR at last follow-up of 81% ± 35%. No patients developed malignancy from the ablated TGDCs.

CONCLUSIONS

EA for treatment of TGDCs achieved acceptable rates of immediate and long-term efficacy with a low complication rate, and can be considered as a first-line treatment for the management of TGDCs.

KEY POINTS

• The immediate success rate of EA for the treatment of TGDCs was 81% (55/68), with a mean VRR within 3 months of 73% ± 31%. • For the median follow-up of 69 months (range, 24-131 months), the long-term success rate was 83% (35/42), with a mean VRR at last follow-up of 81% ± 35%. • No patients developed malignancy from the ablated TGDCs but one patient (1.5%, 1/68) developed wound inflammation after the first EA.

Who spends more to combat COVID-19 social risks and why?

COVID-19 has gone beyond a public health crisis and poses a serious threat to people's livelihoods. In response to the growing employment and income crisis, most OECD countries have introduced various policies and programs to alleviate rapidly rising social risks and stabilise people's livelihoods. However, these measures vary, with some governments spending only 1% of GDP in 2020, while others spent more than 10%. We conducted a multiple regression analysis to examine factors associated with the level of additional social spending in 31 OECD countries. The results indicate that lower generosity of unemployment benefits was associated with additional social policy spending. However, contrary to the hypothesis, higher additional spending was found among countries with higher levels of government debt. We ended with policy recommendations.

Thyroid-dedicated internally-cooled wet electrode for benign thyroid nodules: experimental and clinical study

BACKGROUND

To assess the effects of radiofrequency ablation (RFA) using an internally-cooled wet (ICW) electrode in ex vivo bovine liver and evaluate the feasibility of the ICW electrode for benign thyroid nodules.

METHODS

We developed an 18-gauge ICW electrode with a microhole at the distal tip for tissue infusion of chilled (0 - 4 °C) isotonic saline (rate = 1.5 ml/min). RFA using ICW and IC electrodes were performed in bovine livers (40 pairs, 1-cm active tip, 50 W, 1-min). We compared the morphological characteristics of ablation zones and presence of carbonization. Twenty patients with benign thyroid nodules larger than 5 ml were prospectively enrolled in a clinical study and underwent ultrasound-guided RFA with ICW electrodes. Ultrasound examinations, laboratory data, and symptom and cosmetic scores were evaluated preprocedure and 1 and 6 months after the procedure.

RESULTS

In the ex vivo study, the ICW achieved significantly larger ablation zones than the IC (p<.001). In the clinical study, ICW electrodes were tolerable in all patients. At last follow-up, nodule volume had decreased from 15.6 ± 12.1 ml to 4.1 ± 4.3 ml (p<.001), and the mean volume reduction ratio (VRR) was 73.3 ± 13.7% at 6.0 months follow-up. Cosmetic and symptom scores were reduced from 3.52 ± 1.03 to 2.65 ± 0.88 and 3.10 ± 2.17 to 0.85 ± 0.99 (both p<.001), respectively. After RFA, thyroid function was well preserved in all patients, and mean thyroglobulin level decreased from 36.6 ± 52.1 ng/ml to 26.9 ± 62.2 ng/ml. One patient experienced a temporary voice change that recovered within a week.

CONCLUSIONS

We developed a thyroid-dedicated ICW electrode that we showed to be feasible and effective in patients with benign thyroid nodules.

Immunoglobulin G4-Related Thyroid Disease: A Single-Center Experience and Literature Review

BACKGROUND

Immunoglobulin G4 (IgG4)-related disease is an entity that can involve the thyroid gland. The spectrum of IgG4-related thyroid disease (IgG4-RTD) includes Hashimoto thyroiditis (HT) and its fibrotic variant, Riedel thyroiditis, as well as Graves' disease. The early diagnosis of IgG4-RTD is important because it is a medically treatable disease, and a delay in the diagnosis might result in unnecessary surgery. We present a case series of IgG4-RTD with a review of the literature.

METHODS

We retrospectively reviewed the clinical presentation and the radiological and pathological findings of patients diagnosed with IgG4-RTD between 2017 and 2021 at a tertiary medical center in Korea. We also conducted a literature review of IgG4-RTD.

RESULTS

Five patients were diagnosed with IgG4-RTD during the study period. The patients' age ranged from 31 to 76 years, and three patients were men. Most patients visited the clinic for a neck mass, and hypoechogenic nodular lesions were observed on neck ultrasonography. Three patients had IgG4 HT, and two patients had IgG4 Riedel thyroiditis. All patients developed hypothyroidism that necessitated L-thyroxine replacement. The diagnosis of IgG4-RTD was confirmed after a pathological examination of the surgical specimen in the first two cases. However, the early diagnosis was possible after a core needle biopsy in three clinically suspected patients.

CONCLUSION

The diagnosis of IgG4-RTD requires clinical suspicion combined with serology and histological analyses using IgG4 immunostaining. The early diagnosis of IgG4-RTD is difficult; thus, biopsy with IgG4 immunostaining and serum IgG4 measurements will help diagnose patients suspected of having IgG4-RTD.

Radiofrequency ablation of recurrent thyroid cancers: anatomy-based management

Although differentiated thyroid cancer has an excellent prognosis and low mortality, its recurrence rate has been reported to be very high. While surgery is recommended as the standard treatment for recurrent thyroid cancer, reoperation may increase the incidence of complications due to fibrosis and anatomical distortion. In patients with high surgical risk or those who refuse repeated surgery, ultrasonography-guided ablation techniques including radiofrequency ablation, ethanol ablation, and laser ablation are suggested as alternative treatments. In this manuscript, we introduce an anatomy-based management concept for radiofrequency ablation for recurrent thyroid cancer, and present a review of the relevant literature, including indications, basic techniques, clinical outcomes, and complications.

Temporal change in the diagnosis and treatment rates of osteoporosis: results from the Korea National Health and Nutrition Examination Survey

To compare the diagnosis andtreatment rates of osteoporosis and diabetes in Korea, a nationwide database was used. The results showed that although osteoporosis management is improving, it is still lower compared with that of diabetes; thus, further efforts are needed in this regard.

INTRODUCTION

This study aimed to re-evaluate the diagnosis and treatment of osteoporosis from the KNHANES 2016-2017 and compare the temporal change of the rate with those of diabetes as another prevalent chronic disease in South Korea.

METHODS

The prevalence of osteoporosis in 2016 was estimated using the previous data classified by age groups (50-59,60-69, and ≥70years) and the 2016 Korean census data. The physician diagnosis and treatment rates of osteoporosis in adults aged ≥50years were estimated using the 2016-2017 KNHANES data. The physician diagnosis and treatment rates of diabetes were evaluated using the KNHANES 2008-2009 and 2016-2017 data.

RESULTS

The estimated physician diagnosisrate of osteoporosis increased from 29.9% in females and 5.8% in males in 2008-2009 to 62.8% in females and 22.8% in males in 2016-2017. The treatment rate for the estimated total number of patients with osteoporosis increased from 14.4% in females and 3.8% in males in 2008-2009 to 32.2% in females and 9.0% in males in 2016-2017. An increasing trend in the estimated treatment rateof physician-diagnosed osteoporosis patients was not observed (48.3% [2008-2009] vs 51.5% [2016-2017] in females; 42.6% [2008-2009] vs 42.2% [2016-2017] in males). The physician diagnosis and treatment rates of diabetes were considerably better and more stable than those of osteoporosis.

CONCLUSION

Osteoporosis management in South Korea is improving but is insufficient compared with diabetes management. More extensive efforts are needed to improve the diagnosis and treatment rates of osteoporosis.

Neuroimaging Findings in Patients with COVID-19: A Systematic Review and Meta-Analysis

Objective

Central nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19.

Materials and Methods

A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality.

Results

A total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings.

Conclusion

Abnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.

Histogram analysis of arterial spin labeling perfusion data to determine the human papillomavirus status of oropharyngeal squamous cell carcinomas

PURPOSE

To evaluate the correlation between histogram parameters derived from pseudo-continuous arterial spin labeling (PCASL) and human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (OPSCC).

METHODS

This study included a total of 58 patients (HPV-positive: n = 45; -negative: n = 13) from a prospective cohort of consecutive patients aged ≥ 18 years, who were newly diagnosed with oropharyngeal squamous cell carcinoma. All patients were required to have undergone pre-treatment MRI with PCASL to measure regional perfusion. The region of interest was drawn by two radiologists, encompassing the entire tumor volume on all corresponding slices. Differences in the histogram parameters derived from tumor blood flow (TBF) in ASL were assessed for HPV-positive and -negative patients. Receiver operating characteristic curve analysis was performed to determine the best differentiating parameters, and a leave-one-out cross-validation was used.

RESULTS

Patients with HPV-positive OPSCC showed a significantly lower overall standard deviation and 95th percentile value of tumor blood flow (P < .007). The standard deviation of TBF was the single best predictive parameter. Leave-one-out cross-validation tests revealed that the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity were 0.745, 75.9%, 75.6%, and 76.9%, respectively.

CONCLUSION

PCASL revealed differences in perfusion parameters according to HPV status in patients with OPSCC, reflecting their distinct histopathology.

Diagnostic Performance of the Modified Korean Thyroid Imaging Reporting and Data System for Thyroid Malignancy: A Multicenter Validation Study

OBJECTIVE

To evaluate the diagnostic performance of the modified Korean Thyroid Imaging Reporting and Data System (K-TIRADS), and compare it with the 2016 version of K-TIRADS using the Thyroid Imaging Network of Korea.

MATERIALS AND METHODS

Between June and September 2015, 5708 thyroid nodules (≥ 1.0 cm) from 5081 consecutive patients who had undergone thyroid ultrasonography at 26 institutions were retrospectively evaluated. We used a biopsy size threshold of 2 cm for K-TIRADS 3 and 1 cm for K-TIRADS 4 (modified K-TIRADS 1) or 1.5 cm for K-TIRADS 4 (modified K-TIRADS 3). The modified K-TIRADS 2 subcategorized the K-TIRADS 4 into 4A and 4B, and the cutoff sizes for the biopsies were defined as 1 cm for K-TIRADS 4B and 1.5 cm for K-TIRADS 4A. The diagnostic performance and the rate of unnecessary biopsies of the modified K-TIRADS for detecting malignancy were compared with those of the 2016 K-TIRAD, which were stratified by nodule size (with a threshold of 2 cm).

RESULTS

A total of 1111 malignant nodules and 4597 benign nodules were included. The sensitivity, specificity, and unnecessary biopsy rate of the benign nodules were 94.9%, 24.4%, and 60.9% for the 2016 K-TIRADS; 91.0%, 39.7%, and 48.6% for the modified K-TIRADS 1; 84.9%, 45.9%, and 43.5% for the modified K-TIRADS 2; and 76.1%, 50.2%, and 40.1% for the modified K-TIRADS 3. For small nodules (1-2 cm), the diagnostic sensitivity of the modified K-TIRADS decreased by 5.2-25.6% and the rate of unnecessary biopsies reduced by 19.2-32.8% compared with those of the 2016 K-TIRADS (p < 0.001). For large nodules (> 2 cm), the modified K-TIRADSs maintained a very high sensitivity for detecting malignancy (98%).

CONCLUSION

The modified K-TIRADSs significantly reduced the rate of unnecessary biopsies for small (1-2 cm) nodules while maintaining a very high sensitivity for malignancy for large (> 2 cm) nodules.

Prediction model for cervical lymph node metastasis in human papillomavirus-related oropharyngeal squamous cell carcinomas

OBJECTIVES

To develop and validate a risk scoring system based on clinical and imaging findings to predict lymph node metastasis from HPV-related oropharyngeal squamous cell carcinomas.

METHODS

This study population who had undergone neck dissections or lymph node biopsies in patients with HPV+ OPSCC was obtained from a historical cohort from two tertiary referral hospitals. The training set from one hospital included 455 lymph nodes from 82 patients, and the test set from the other hospital included 150 lymph nodes from 42 patients. The baseline clinical and imaging findings on pretreatment CT or MR were investigated and the reference standards were the histopathologic results. A risk scoring system was constructed based on logistic regression and validated both internally and externally.

RESULTS

A 7-point risk scoring system was developed based on the following variables: central necrosis, infiltration of adjacent planes, lymph node level, and the maximal axial diameter of the lymph node. This risk scoring system showed good discriminative ability for metastasis in the training set (C-statistic 0.952; 95% CI, 0.931-0.972) and test set (C-statistic 0.968, 95% CI, 0.936-0.999) and good calibration ability in the training set (p = 0.723) and test set (p = 0.253).

CONCLUSIONS

We developed and validated a reliable risk scoring system that predicts lymph node metastasis from HPV+ OPSCCs based on the clinical data and pretreatment imaging findings. We expect this risk scoring system to be a useful guide for better decision-making in practice.

KEY POINTS

• It is important to diagnose lymph node metastasis from HPV+ OPSCC for treatment planning; however, there has been little research on that. • We developed and externally validated a new scoring system for stratifying the risk of lymph node metastasis from HPV+ OPSCC based on clinical and imaging data. • A predictive model combining both clinical and imaging data showed high diagnostic accuracy and efficiency for lymph node metastasis from HPV+ OPSCC.

Interobserver Reproducibility in Sonographic Measurement of Diameter and Volume of Papillary Thyroid Microcarcinoma

Background: Active surveillance is recommended as an alternative to immediate surgery for low-risk papillary thyroid microcarcinoma (PTMC), and determining meaningful changes in diameter and volume on ultrasonography (US) is critical. However, interobserver reproducibility of the sonographic measurement of maximum diameter and volume of PTMC has not been well established. We aimed to determine the reproducibility in the measurement of maximum diameter and volume of PTMC on US. Methods: Consecutive patients who underwent US for pathologically proven PTMC between December 2018 and December 2019 were retrospectively reviewed. Two observers independently performed sonographic measurement of each nodule using standardized measurement methods. Each observer measured maximum transverse, anteroposterior, and longitudinal nodule diameters, and using these, nodule volume was calculated using the ellipsoid formula. Interobserver reproducibility in the measurement of the maximum diameter and volume was assessed using percentage reproducibility coefficient (RC). Z-tests of the intraclass correlation coefficients (ICCs) were used to compare the interobserver reproducibility in subgroups defined according to sonographic characteristics, such as the presence of microcalcification, nodule size, and parenchymal heterogeneity. Results: A total of 197 thyroid nodules from 188 patients were included in the study series. The percentage RCs were 71.8% [95% confidence interval, CI 65.4-79.7%] and 23.7% [CI 21.6-26.3%] for volume and maximum diameter measurements, respectively. There were no significant differences noted in the ICC values according to nodule orientation, presence of calcifications, size, or parenchymal heterogeneity. Conclusion: For PTMC, a difference of up to 24% in the maximum diameter and 72% in the volume may be considered to be within measurement error on US. This value may be used to determine the cutoff for defining meaningful change in the maximum diameter and volume for PTMC during active surveillance.

Efficacy and safety of high-intensity focused ultrasound (HIFU) for treating benign thyroid nodules: a systematic review and meta-analysis

BACKGROUND

High-intensity focused ultrasound (HIFU) is an emerging thermal ablation technique that has been successfully applied to various benign thyroid nodules.

PURPOSE

To evaluate the efficacy and safety of HIFU for the treatment of benign thyroid nodules.

MATERIAL AND METHODS

The Ovid-MEDLINE and EMBASE databases were searched up to 9 July 2018 for studies describing the use of HIFU to treat benign thyroid nodules. We included studies that have outcomes with sufficient detail to evaluate the volume reduction rate (VRR). The pooled proportions of VRR ≥50% and pooled VRR at one, three, and six months after HIFU were assessed using random-effects modeling. Heterogeneity among studies was determined using Chi-square statistics for pooled estimates and the inconsistency index I².

RESULTS

Seven studies were included in the systematic review and four in the meta-analysis. The pooled VRR at one, three, and six months after HIFU were 17.59 (95% confidence interval [CI] 12.56-22.62), 48.93 (95% CI 42.20-55.66), and 60.43 (95% CI 51.88-68.98). The pooled proportions of VRR ≥50% at six months after HIFU were 75% (95% CI 53-89; I²=73.6%). There were no major complications of HIFU.

CONCLUSION

HIFU may be a safe and effective treatment modality for benign thyroid nodules, especially for small nodules.

MRI Predictors of Malignant Transformation in Patients with Inverted Papilloma: A Decision Tree Analysis Using Conventional Imaging Features and Histogram Analysis of Apparent Diffusion Coefficients

OBJECTIVE

Preoperative differentiation between inverted papilloma (IP) and its malignant transformation to squamous cell carcinoma (IP-SCC) is critical for patient management. We aimed to determine the diagnostic accuracy of conventional imaging features and histogram parameters obtained from whole tumor apparent diffusion coefficient (ADC) values to predict IP-SCC in patients with IP, using decision tree analysis.

MATERIALS AND METHODS

In this retrospective study, we analyzed data generated from the records of 180 consecutive patients with histopathologically diagnosed IP or IP-SCC who underwent head and neck magnetic resonance imaging, including diffusion-weighted imaging and 62 patients were included in the study. To obtain whole tumor ADC values, the region of interest was placed to cover the entire volume of the tumor. Classification and regression tree analyses were performed to determine the most significant predictors of IP-SCC among multiple covariates. The final tree was selected by cross-validation pruning based on minimal error.

RESULTS

Of 62 patients with IP, 21 (34%) had IP-SCC. The decision tree analysis revealed that the loss of convoluted cerebriform pattern and the 20th percentile cutoff of ADC were the most significant predictors of IP-SCC. With these decision trees, the sensitivity, specificity, accuracy, and C-statistics were 86% (18 out of 21; 95% confidence interval [CI], 65-95%), 100% (41 out of 41; 95% CI, 91-100%), 95% (59 out of 61; 95% CI, 87-98%), and 0.966 (95% CI, 0.912-1.000), respectively.

CONCLUSION

Decision tree analysis using conventional imaging features and histogram analysis of whole volume ADC could predict IP-SCC in patients with IP with high diagnostic accuracy.

Recurrence and additional treatment of cystic thyroid nodules after ethanol ablation: validation of three proposed criteria

PURPOSE

We evaluated the use of three criteria to determine the need for additional treatment of cystic thyroid nodules after their recurrence following ethanol ablation (EA).

METHODS

In total, 154 patients (male:female=30:124; mean age, 53.4 years; range, 23 to 79 years) with 154 thyroid nodules (49 cystic and 105 predominantly cystic nodules) who presented between January 2014 and August 2017 were enrolled. All patients underwent follow-up ultrasonography (US) 1 month after EA, and were divided into therapeutic success and failure groups. Therapeutic success was defined as the absence of any residual fluid or sufficient volume reduction (≥50%) with improvement of nodule-related symptoms. The therapeutic failure was defined according to three previously suggested criteria for recommending additional treatment: nodules with ≥1 mL of remnant fluid (criterion 1), volume reduction <50% (criterion 2), and demonstration of a solid component with vascularity (criterion 3).

RESULTS

Thyroid nodules treated by EA showed significant volume reduction (18.4±21.6 mL to 4.2±6.5 mL [1-month follow-up] to 1.9±3.3 mL [final follow-up], P<0.001) and improvement in clinical problems. Therapeutic failure were 26 patients according to criteria 1, 14 patients according to criteria 2, and 35 patients according to criteria 3. Additional treatment was unnecessary in 81.3%, 70.0%, and 77.8% of patients deemed to need it according to criteria 1, 2, and 3, respectively.

CONCLUSION

The choice to perform additional treatment after EA should be made according to a combination of clinical problems and US features. Understanding this concept will be useful in planning further treatment following US-guided EA.

Computer-Aided Diagnosis System for the Evaluation of Thyroid Nodules on Ultrasonography: Prospective Non-Inferiority Study according to the Experience Level of Radiologists

Objective

To determine whether a computer-aided diagnosis (CAD) system for the evaluation of thyroid nodules is non-inferior to radiologists with different levels of experience.

Materials and Methods

Patients with thyroid nodules with a decisive diagnosis of benign or malignant nodule were consecutively enrolled from November 2017 to September 2018. Three radiologists with different levels of experience (1 month, 4 years, and 7 years) in thyroid ultrasound (US) reviewed the thyroid US with and without using the CAD system. Statistical analyses included non-inferiority testing of the diagnostic accuracy for malignant thyroid nodules between the CAD system and the three radiologists with a non-inferiority margin of 10%, comparison of the diagnostic performance, and the added value of the CAD system to the radiologists.

Results

Altogether, 197 patients were included in the study cohort. The diagnostic accuracy of the CAD system (88.48%, 95% confidence interval [CI] = 82.65–92.53) was non-inferior to that of the radiologists with less experience (1 month and 4 year) of thyroid US (83.03%, 95% CI = 76.52–88.02; p < 0.001), whereas it was inferior to that of the experienced radiologist (7 years) (95.76%, 95% CI = 91.37–97.96; p = 0.138). The sensitivity and negative predictive value of the CAD system were significantly higher than those of the less-experienced radiologists were, whereas no significant difference was found with those of the experienced radiologist. A combination of US and the CAD system significantly improved sensitivity and negative predictive value, although the specificity and positive predictive value deteriorated for the less-experienced radiologists.

Conclusion

The CAD system may offer support for decision-making in the diagnosis of malignant thyroid nodules for operators who have less experience with thyroid US.

Oropharyngeal squamous cell carcinoma: radiomic machine-learning classifiers from multiparametric MR images for determination of HPV infection status

We investigated the ability of machine-learning classifiers on radiomics from pre-treatment multiparametric magnetic resonance imaging (MRI) to accurately predict human papillomavirus (HPV) status in patients with oropharyngeal squamous cell carcinoma (OPSCC). This retrospective study collected data of 60 patients (48 HPV-positive and 12 HPV-negative) with newly diagnosed histopathologically proved OPSCC, who underwent head and neck MRIs consisting of axial T1WI, T2WI, CE-T1WI, and apparent diffusion coefficient (ADC) maps from diffusion-weighted imaging (DWI). The median age was 59 years (the range being 35 to 85 years), and 83.3% of patients were male. The imaging data were randomised into a training set (32 HPV-positive and 8 HPV-negative OPSCC) and a test set (16 HPV-positive and 4 HPV-negative OPSCC) in each fold. 1618 quantitative features were extracted from manually delineated regions-of-interest of primary tumour and one definite lymph node in each sequence. After feature selection by using the least absolute shrinkage and selection operator (LASSO), three different machine-learning classifiers (logistic regression, random forest, and XG boost) were trained and compared in the setting of various combinations between four sequences. The highest diagnostic accuracies were achieved when using all sequences, and the difference was significant only when the combination did not include the ADC map. Using all sequences, logistic regression and the random forest classifier yielded higher accuracy compared with the that of the XG boost classifier, with mean area under curve (AUC) values of 0.77, 0.76, and 0.71, respectively. The machine-learning classifier of non-invasive and quantitative radiomics signature could guide the classification of the HPV status.

Unnecessary thyroid nodule biopsy rates under four ultrasound risk stratification systems: a systematic review and meta-analysis

OBJECTIVES

To summarize and compare unnecessary biopsy rates and diagnostic performance in the examination of thyroid nodules according to four representative US-based risk stratification systems.

METHODS

MEDLINE/PubMed and EMBASE databases were searched to identify original articles investigating unnecessary biopsy rates according to at least one of the following guidelines: ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS. The unnecessary biopsy rates for each risk stratification system were pooled using a random-effects model. Meta-regression analyses were performed to explore heterogeneity. Diagnostic odds ratios (DORs) for the appropriate selection of thyroid nodules for fine-needle aspiration were also pooled using a bivariate random-effects model.

RESULTS

Eight articles including 13,092 thyroid nodules met the eligibility criteria and were included. The pooled unnecessary biopsy rates of ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS were 25% (95% CI, 22-29%), 51% (95% CI, 44-58%), 38% (95% CI, 16-66%), and 55% (95% CI, 42-67%), respectively. The pooled unnecessary biopsy rate of ACR-TIRADS was significantly lower than that of ATA (p < .001) and K-TIRADS (p < .001), and also lower than that of EU-TIRADS, but not reaching statistical significance (p = .087). The pooled DORs of ACR-TIRADS, ATA, and K-TIRADS were 5.9 (95% CI, 3.6-9.6), 6.3 (95% CI, 4.5-8.8), and 4.5 (95% CI, 1.7-11.6), respectively, with the differences not being statistically significant.

CONCLUSIONS

ACR-TIRADS showed a lower unnecessary biopsy rate than the other risk stratification systems albeit DOR was comparable between ACR-TIRADS, ATA, and K-TIRADS. Future revisions of each system should be made by referring to ACR-TIRADS to reduce unnecessary biopsy rates.

KEY POINTS

• The pooled unnecessary biopsy rates of ACR-TIRADS, ATA, EU-TIRADS, and K-TIRADS were 25% (95% CI, 22-29%), 51% (95% CI, 44-58%), 38% (95% CI, 16-66%), and 55% (95% CI, 42-67%), respectively. • The pooled unnecessary biopsy rate of ACR-TIRADS was significantly lower than that of ATA (p < .001) and K-TIRADS (p < .001). • The pooled DORs of ACR-TIRADS, ATA, and K-TIRADS were 5.9 (95% CI, 3.6-9.6), 6.3 (95% CI, 4.5-8.8), and 4.5 (95% CI, 1.7-11.6), respectively, with the differences not being statistically significant.

Efficacy of radiofrequency ablation for recurrent thyroid cancer invading the airways

OBJECTIVES

To evaluate the efficacy of radiofrequency ablation (RFA) in patients with recurrent thyroid cancer invading the airways.

METHODS

We reviewed patients who had undergone RFA for recurrent thyroid cancer in the central compartment after total thyroidectomy between January 2008 and December 2018. All tumors were classified according to their association with the laryngeal structure and trachea. The volume reduction rate (VRR) and complete disappearance rate were calculated, and their differences were determined relative to the association between the tumor and trachea. Complication rates associated with RFA were evaluated.

RESULTS

The study population included 119 patients with 172 recurrent tumors. Mean VRR was 81.2% ± 55.7%, with 124 tumors (72.1%) completely disappearing after a mean follow-up of 47.9 ± 35.4 months. The complete disappearance rate of recurrent tumors not in contact with the trachea was highest, followed by tumors forming acute angles, right angles, and obtuse angles with the trachea, and tumors with intraluminal tracheal invasion (p value < 0.001). The overall complication rate was 21.4%.

CONCLUSIONS

RFA is effective and safe for the local control of recurrent tumors in the central neck compartment after total thyroidectomy, even for tumors invading the airways, and may be considered an alternative to surgical resection. The inverse relationship between RFA efficacy and airway invasion suggests that early RFA may benefit patients with recurrent tumors in the central neck compartment.

KEY POINTS

• RFA achieved a mean VRR of 81.2% ± 55.7% and complete disappearance of 124 tumors (72.1%) after a mean follow-up of 47.9 ± 35.4 months. • The complete disappearance rate of recurrent tumors not in contact with the trachea was the highest, followed by tumors forming acute angles, right angles, and obtuse angles with the trachea, and tumors with intraluminal tracheal invasion. • Stent-assisted RFA may be a good alternative for palliative treatment of recurrent tumors with intraluminal tracheal invasion.

Clinical applications of Doppler ultrasonography for thyroid disease: consensus statement by the Korean Society of Thyroid Radiology

Doppler ultrasonography (US) is widely used for the differential diagnosis of thyroid nodules, metastatic cervical lymph nodes in patients with thyroid cancer, and diffuse parenchymal disease, as well as for guidance in various US-guided procedures, including biopsy and ablation. However, controversies remain regarding the appropriate use and interpretation of Doppler US. Therefore, the Korean Society of Thyroid Radiology organized a taskforce to develop a consensus statement on the clinical use of Doppler US for thyroid disease. The review and recommendations in this article are based on a comprehensive analysis of the current literature and the consensus of experts.

Thin-Section MR Imaging for Carotid Cavernous Fistula

BACKGROUND AND PURPOSE

Carotid-cavernous fistulas are abnormal vascular shunts that can cause various neurologic or orbital symptoms. The purpose of this retrospective study was to evaluate the diagnostic performance of thin-section MR imaging for carotid cavernous fistula in patients with clinically suspected carotid cavernous fistula, and to identify possible imaging predictors of carotid cavernous fistula.

MATERIALS AND METHODS

A total of 98 patients who were clinically suspected of having carotid cavernous fistula (according to their symptoms and physical examinations) between January 2006 and September 2018 were included in this study. The patients underwent pretreatment thin-section MR imaging and DSA. Thin-section MR imaging consisted of 2D coronal T1- and T2WI with 3-mm thickness and 3D contrast-enhanced T1WI with 0.6 mm thickness. The diagnostic performance of thin-section MR imaging for carotid cavernous fistula was evaluated with the reference standard of DSA. Univariate logistic regression analysis was performed to determine possible imaging predictors of carotid cavernous fistula.

RESULTS

Among the 98 patients, DSA confirmed 38 as having carotid cavernous fistula. The overall accuracy, sensitivity, and specificity of thin-section MR imaging were 88.8%, 97.4%, and 83.3%, respectively. Possible imaging predictors on thin-section MR imaging included abnormal contour of the cavernous sinus (OR: 21.7), internal signal void of the cavernous sinus (OR: 15.3), prominent venous drainage flow (OR: 54.0), and orbital/periorbital soft tissue swelling (OR: 40.4).

CONCLUSIONS

Thin-section MR imaging provides high diagnostic performance and possible imaging predictors of carotid cavernous fistula in patients with clinically suspected carotid cavernous fistula. Thin-section MR imaging protocols could help decide appropriate management plans for patients with clinically suspected carotid cavernous fistula.

Diagnostic Accuracy of MRI-Based Morphometric Parameters for Detecting Olfactory Nerve Dysfunction

BACKGROUND AND PURPOSE

Although olfactory dysfunction is a common cranial nerve disorder, there are no simple objective morphometric criteria to assess olfactory dysfunction. The aim of this study was to evaluate the diagnostic performance of MR imaging morphometric parameters for detecting olfactory dysfunction.

MATERIALS AND METHODS

This prospective study enrolled patients from those presenting with olfactory symptoms who underwent both an olfactory function test and MR imaging. Controls without olfactory dysfunction were recruited during the preoperative work-up for pituitary adenoma. Two independent neuroradiologists measured the olfactory bulb in 3D and assessed olfactory bulb concavity on MR imaging while blinded to the clinical data. Diagnostic performance was assessed using receiver operating characteristic curve analysis.

RESULTS

Sixty-four patients and 34 controls were enrolled. The patients were significantly older than the controls (mean age, 57.8 ± 11.9 years versus 47.1 ± 12.1 years; P < .001). Before age adjustment, the olfactory bulb height was the only olfactory bulb parameter showing a significant difference between patients and controls (1.6 ± 0.3 mm versus 2.0 ± 0.3 mm, P < .001). After age adjustment, all parameters and olfactory bulb concavity showed significant intergroup differences, with the olfactory bulb height having the highest area under the curve (0.85). Olfactory bulb height was confirmed to be the only significant parameter showing a difference in the detection of olfactory dysfunction in 22 pairs after matching for age and sex (area under the curve = 0.87, P < .001). Intraclass correlation coefficients revealed moderate-to-excellent degrees of inter- and intrareader agreement.

CONCLUSIONS

MR imaging morphometric analysis can differentiate patients with olfactory dysfunction, with the olfactory bulb height having the highest diagnostic performance for detecting olfactory dysfunction irrespective of age.

Diagnostic Performance of Four Ultrasound Risk Stratification Systems: A Systematic Review and Meta-Analysis

Background: Several ultrasound (US)-based risk stratification systems have been increasingly used for the optimal management of thyroid nodules. However, there are considerable discrepancies across these systems. This study aimed to summarize and compare the category-based diagnostic performance in the detection of thyroid cancer of different US-based risk stratification systems from four societies: the American College of Radiology-Thyroid Imaging Reporting and Data System (ACR-TIRADS), the American Thyroid Association (ATA), the Korean Thyroid Association/Korean Society of Thyroid Radiology (KTA/KSThR; K-TIRADS), and the European Thyroid Association (EU-TIRADS). Methods: MEDLINE/PubMed and EMBASE databases were searched to identify original articles investigating the category-based diagnostic performance according to at least one of the following guidelines: ACR-TIRADS, ATA, K-TIRADS, and EU-TIRADS. Pooled sensitivity and specificity were calculated using a bivariate random-effects model. A subgroup analysis on nodules of 1 cm or larger and a meta-regression analysis to identify factors associated with the diagnostic performance were performed. Results: A total of 29 articles including 33,748 thyroid nodules met the eligibility criteria and were included in the analysis. For ACR-TIRADS, the pooled sensitivity and specificity were, respectively, 66% and 91% for category 5 and 95% and 55% for category 4 or 5. For ATA, the pooled sensitivity and specificity were, respectively, 74% and 88% for category 5 and 91% and 64% for category 4 or 5. For K-TIRADS, the pooled sensitivity and specificity were, respectively, 55% and 95% for category 5 and 89% and 64% for category 4 or 5. For EU-TIRADS, the pooled sensitivity and specificity were, respectively, 82% and 90% for category 5 and 96% and 52% for category 4 or 5. Study location, proportion of female patients and malignant nodules, and study design were associated with study heterogeneity. Conclusions: The overall diagnostic performance of the four US-based risk stratification systems was comparable.

Sonographic Assessment of the Extent of Extrathyroidal Extension in Thyroid Cancer

Objective

This study aimed to determine the sonographic features suggestive of extrathyroidal extension (ETE) of thyroid cancers.

Materials and Methods

We retrospectively reviewed the sonographic images of 1656 consecutive patients who had undergone thyroidectomy in 2017. The diagnostic performance of sonographic features suggestive of ETE was evaluated using operation and histopathologic reports. Sonographic features for gross ETE to the strap muscle and minor ETE were assessed for thyroid cancer abutting the anterolateral thyroid capsule. Sonographic features for tracheal invasion were assessed according to whether the angle between the tumor and the trachea was an acute, right, or obtuse angle. Sonographic features for recurrent laryngeal nerve (RLN) invasion were assessed based on the association between the tumor and tracheoesophageal groove (TEG) as preserved normal tissue, abutting or protruding into the TEG.

Results

ETE was observed in 783 patients (47.3%), including 123 patients with gross ETE (7.4% [strap muscle, n = 97; RLN, n = 24; and trachea, n = 14]) and 660 patients with minor ETE (39.9%). Regarding the diagnosis of gross and minor ETE to the strap muscle, sonographic features of replacement of the strap muscle and capsular disruption showed the highest positive predictive value (75.9% and 58.5%, respectively). Thyroid cancer forming an obtuse angle with the trachea had the highest sensitivity for the diagnosis of tracheal invasion (85.7%), and thyroid cancer protrusion into the TEG showed the highest sensitivity for the diagnosis of RLN (83.3%).

Conclusion

Sonography is considered beneficial in the diagnosis of ETE to the strap muscle, trachea, and RLN. Assessment of ETE is important for the accurate staging of thyroid cancer, which in turn determines the extent of surgery or whether active surveillance is appropriate or not.

Prognostic Value of Radiologic Extranodal Extension in Human Papillomavirus-Related Oropharyngeal Squamous Cell Carcinoma

Objective

To determine whether radiologic extranodal extension (ENE) appearing on pretreatment CT and MRI could predict the prognosis in patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC).

Materials and Methods

The study population was obtained from a historical cohort diagnosed with HPV-related OPSCC. A total of 134 OPSCC patients who had a metastatic lymph node on pretreatment CT or MRI were included, and radiologic ENE was evaluated by two experienced head and neck radiologists. Kaplan-Meier and multivariate Cox regression analyses were performed to evaluate the impact of radiologic ENE on progression-free survival (PFS). The diagnostic performance of CT and MRI for the diagnosis of ENE was also evaluated in patients who underwent neck dissection.

Results

Seventy patients (52.2%) showed radiologic ENE-positive findings. Although patients showing radiologic ENE had a worse 3-year PFS (83.7% vs. 95.3%, p = 0.023), the association between radiologic ENE and PFS was not statistically significant on multivariate analysis (p = 0.141; hazard ratio, 2.68; 95% confidence interval, 0.72–9.97). CT or MRI had a sensitivity of 62%, specificity of 77.8%, and accuracy of 71.9% for predicting pathologic ENE.

Conclusion

Radiologic ENE on CT or MRI did not predict poor PFS in patients with HPV-related OPSCC, although there was a trend towards worse PFS. Further studies are warranted to determine whether radiologic ENE is a useful imaging biomarker to risk-stratify patients with HPV-related OPSCC.

Degenerating Thyroid Nodules: Ultrasound Diagnosis, Clinical Significance, and Management

Degenerating nodules (DNs), which primarily manifest as benign thyroid nodules, are one of the main causes of discordance in ultrasonography (US) and cytological assessments. Intranodular hemorrhage is one of the mechanisms contributing to discordant nodules, and an impaired blood supply may explain further DN shrinkage and infarction. The surgical specimens can be divided into acute and chronic stages based on the histological changes, which usually mimic the US features of malignant tumors. Serial US follow-up should be recommended instead of other unnecessary procedures. However, repeated fine-needle aspiration, diagnostic surgery, or core-needle biopsy may still be necessary for indeterminable or highly suspicious DNs.

Clinical practice guidelines for radiofrequency ablation of benign thyroid nodules: a systematic review

Purpose

Thermal ablation is a novel treatment alternative for benign thyroid nodules, and one of the most promising thermal ablation techniques is radiofrequency ablation (RFA). Considering the increasing use of thyroid RFA, some scientific societies have proposed clinical practice guidelines. We systemically reviewed and compared these guidelines for thyroid RFA to identify a standard treatment strategy that represents the positions of most societies.

Methods

We searched the MEDLINE and EMBASE databases for studies with human participants that were published in English between January 1, 2000 and August 2, 2019. Studies containing clinical practice guidelines for the RFA of benign thyroid nodules were included. We extracted data regarding indications, pre- and post-procedural evaluations, treatment techniques, and the need to obtain informed consent.

Results

Of the 83 studies found, four studies were included, and one study was added after searching the bibliographies of those articles. The five included studies were guidelines developed by the Korean Society of Thyroid Radiology, a group of experts from Italian scientific societies, the Italian Working Group on Minimally Invasive Treatments of the Thyroid, the United Kingdom’s National Institute for Health and Clinical Excellence, and a group of four professional Austrian thyroid associations. Indications, pre- and post-procedural evaluations, and techniques were similar across studies; however, differences in each of these categories were found.

Conclusion

While the reviewed guidelines are similar with regard to major categories, international guidelines for the RFA of benign thyroid nodules should be established in the future.

Effectiveness of Injecting Cold 5% Dextrose into Patients with Nerve Damage Symptoms during Thyroid Radiofrequency Ablation

BACKGROUND

Although radiofrequency ablation (RFA) is a safe treatment for thyroid tumors, nerve damage is a frequent complication. A previous retrospective study suggested that an injection of cold 5% dextrose in water (5% DW) can reduce nerve damage during RFA. This study validated the efficacy of injecting cold 5% DW for management of nerve damage during RFA.

METHODS

Between November 2017 and December 2018, 242 patients underwent 291 RFA sessions for treatment of benign thyroid nodules or recurrent thyroid cancers. Using a standardized technique, cold (0°C to 4°C) 5% DW was immediately injected around the damaged nerve into patients with any symptoms suggesting nerve damage. The incidence of nerve damage, the volume of 5% DW injected, symptom recovery time and the incidence of permanent nerve damage were evaluated.

RESULTS

Nineteen patients experienced nerve damage symptoms related to 21 RFA sessions, including 17 patients during 19 sessions and two patients on the day after two sessions. Patients with nerve damage symptoms detected during RFA were treated by injection of a mean 41 mL (range, 3 to 260) cold 5% DW, but the two patients who experienced symptoms the next day did not receive cold 5% DW injections. Immediate recovery was observed after 15 RFA sessions in 14 patients. No patient experienced permanent nerve damage.

CONCLUSION

Injection of cold 5% DW is effective in managing nerve damage during RFA of thyroid lesions.

Long-Term Results of Thermal Ablation of Benign Thyroid Nodules: A Systematic Review and Meta-Analysis

BACKGROUND

Ultrasound-guided thermal ablations have become one of the main options for treating benign thyroid nodules. To determine efficacy of thermal ablation of benign thyroid nodules, we performed a meta-analysis of studies with long-term follow-up of more than 3 years.

METHODS

Databases were searched for studies published up to August 25, 2019, reporting patients with benign thyroid nodules treated with thermal ablation and with follow-up data of more than 3 years. Data extraction and quality assessment were performed according to PRISMA guidelines. The analysis yielded serial volume reduction rates (VRRs) of ablated nodules for up to 3 years or more, and adverse effect of ablation during follow-up. Radiofrequency ablation (RFA) and laser ablation (LA) were compared in a subgroup analysis.

RESULTS

The pooled VRRs for ablated nodules showed rapid volume reduction before 12 months, a plateau from 12 to 36 months, and more volume reduction appearing after 36 months, demonstrating long-term maintenance of treatment efficacy. Thermal ablation had an acceptable complication rate of 3.8%. Moreover, patients undergoing nodule ablation showed no unexpected delayed complications during the follow-up period. In the subgroup analysis, RFA was shown to be superior to LA in terms of the pooled VRR and the number of patients who underwent delayed surgery.

CONCLUSION

Thermal ablations are safe and effective methods for treating benign thyroid nodules, as shown by a long follow-up analysis of more than 3 years. In addition, RFA showed superior VRRs compared with LA for the treatment of benign thyroid nodules, with less regrowth and less delayed surgery.