Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

Background: This study aimed to investigate the erosive potential of powdered vitamin C on the bovine enamel tooth surface. Methods: The experiment included five groups: Lemona, Vitagran, Korea Eundan, Coca-Cola (positive controls), and artificialsaliva (negative controls). The pH and titratable acidity were measured. Bovine enamel specimens were immersed in the experimental solutions for 15 minutes each day for 7 days. The surface microhardness was measured using the Vickers hardness number before immersion and on the 1st, 3rd, 5th, and 7th days. The surfaces of the bovine enamel specimens were observed by scanning electron microscopy (SEM). Results: The pH of the experimental groups was as follows: Lemona (2.04±0.04) had the lowest pH, followed by Vitagran(2.56±0.01), the positive control group Coca-Cola (2.60±0.03), Korea Eundan (3.14±0.02), and the negative control group artificial saliva (7.06±0.05). Surface microhardness decreased significantly during the immersion period (p＜0.001). The largest surface microhardness reduction value was shown in Lemona (–201.22±20.60), followed by Vitagran (–190.02±14.73), Korea Eundan (–189.27±27.14), Coca-Cola (–99.28±17.21), artificial saliva (–10.99±9.94). According to the SEM findings, the experimental and positive control groups exhibited rough surfaces with micropores, whereas the negative control group exhibited smooth surfaces before specimen immersion. Conclusion Consuming powdered vitamin C at a low pH may degrade the enamel surface. To reduce the erosive effect, it isrecommended to rinse the mouth with water and brush the teeth after an hour.

Background: This study aimed to investigate the erosive potential of powdered vitamin C on the bovine enamel tooth surface. Methods: The experiment included five groups: Lemona, Vitagran, Korea Eundan, Coca-Cola (positive controls), and artificialsaliva (negative controls). The pH and titratable acidity were measured. Bovine enamel specimens were immersed in the experimental solutions for 15 minutes each day for 7 days. The surface microhardness was measured using the Vickers hardness number before immersion and on the 1st, 3rd, 5th, and 7th days. The surfaces of the bovine enamel specimens were observed by scanning electron microscopy (SEM). Results: The pH of the experimental groups was as follows: Lemona (2.04±0.04) had the lowest pH, followed by Vitagran(2.56±0.01), the positive control group Coca-Cola (2.60±0.03), Korea Eundan (3.14±0.02), and the negative control group artificial saliva (7.06±0.05). Surface microhardness decreased significantly during the immersion period (p＜0.001). The largest surface microhardness reduction value was shown in Lemona (–201.22±20.60), followed by Vitagran (–190.02±14.73), Korea Eundan (–189.27±27.14), Coca-Cola (–99.28±17.21), artificial saliva (–10.99±9.94). According to the SEM findings, the experimental and positive control groups exhibited rough surfaces with micropores, whereas the negative control group exhibited smooth surfaces before specimen immersion. Conclusion Consuming powdered vitamin C at a low pH may degrade the enamel surface. To reduce the erosive effect, it isrecommended to rinse the mouth with water and brush the teeth after an hour.

Background: This study aimed to investigate the erosive potential of powdered vitamin C on the bovine enamel tooth surface. Methods: The experiment included five groups: Lemona, Vitagran, Korea Eundan, Coca-Cola (positive controls), and artificialsaliva (negative controls). The pH and titratable acidity were measured. Bovine enamel specimens were immersed in the experimental solutions for 15 minutes each day for 7 days. The surface microhardness was measured using the Vickers hardness number before immersion and on the 1st, 3rd, 5th, and 7th days. The surfaces of the bovine enamel specimens were observed by scanning electron microscopy (SEM). Results: The pH of the experimental groups was as follows: Lemona (2.04±0.04) had the lowest pH, followed by Vitagran(2.56±0.01), the positive control group Coca-Cola (2.60±0.03), Korea Eundan (3.14±0.02), and the negative control group artificial saliva (7.06±0.05). Surface microhardness decreased significantly during the immersion period (p＜0.001). The largest surface microhardness reduction value was shown in Lemona (–201.22±20.60), followed by Vitagran (–190.02±14.73), Korea Eundan (–189.27±27.14), Coca-Cola (–99.28±17.21), artificial saliva (–10.99±9.94). According to the SEM findings, the experimental and positive control groups exhibited rough surfaces with micropores, whereas the negative control group exhibited smooth surfaces before specimen immersion. Conclusion Consuming powdered vitamin C at a low pH may degrade the enamel surface. To reduce the erosive effect, it isrecommended to rinse the mouth with water and brush the teeth after an hour.

Background: Exercise capacity is associated with lung function decline in chronicobstructive pulmonary disease (COPD) patients, but a discrepancy between exercisecapacity and airflow limitation exists. This study aimed to explore factors contributingto this discrepancy in COPD patients. Methods: Data for this prospective study were obtained from the Korean COPD SubgroupStudy. The exercise capacity and airflow limitation were assessed using the6-minute walk distance (6-MWD; m) and forced expiratory volume in 1 second (FEV1).Participants were divided into four groups: FEV1 >50%+6-MWD >350, FEV1 >50%+6-MWD ≤350, FEV1 ≤50%+6-MWD >350, and FEV1 ≤50%+6-MWD ≤350 and their clinicalcharacteristics were compared. Results: A total of 883 patients (male:female, 822:61; mean age, 68.3±7.97 years) wereenrolled. Among 591 patients with FEV1 >50%, 242 were in the 6-MWD ≤350 group, andamong 292 patients with FEV1 ≤50%, 185 were in the 6-MWD >350 group. The multipleregression analyses revealed that male sex (odds ratio [OR], 8.779; 95% confidence interval[CI], 1.539 to 50.087; p=0.014), current smoking status (OR, 0.355; 95% CI, 0.178to 0.709; p=0.003), and hemoglobin levels (OR, 1.332; 95% CI, 1.077 to 1.648; p=0.008)were significantly associated with discrepancies in exercise capacity and airflow limitationin patients with FEV1 >50%. Meanwhile, in patients with FEV1 ≤50%, diffusioncapacity of carbon monoxide (OR, 0.945; 95% CI, 0.912 to 0.979; p=0.002) was significantlyassociated with discrepancies between exercise capacity and airflow limitation. Conclusion The exercise capacity of COPD patients may be influenced by factors otherthan airflow limitation, so these aspects should be considered when assessing andtreating patients.

Background: This study investigated the diagnostic performance of biopsy criteria in four society ultrasonography risk stratification systems (RSSs) for thyroid nodules, including the 2021 Korean (K)-Thyroid Imaging Reporting and Data System (TIRADS). Methods: The Ovid-MEDLINE, Embase, Cochrane, and KoreaMed databases were searched and a manual search was conducted to identify original articles investigating the diagnostic performance of biopsy criteria for thyroid nodules (≥1 cm) in four widely used society RSSs. Results: Eleven articles were included. The pooled sensitivity and specificity were 82% (95% confidence interval [CI], 74% to 87%) and 60% (95% CI, 52% to 67%) for the American College of Radiology (ACR)-TIRADS, 89% (95% CI, 85% to 93%) and 34% (95% CI, 26% to 42%) for the American Thyroid Association (ATA) system, 88% (95% CI, 81% to 92%) and 42% (95% CI, 22% to 67%) for the European (EU)-TIRADS, and 96% (95% CI, 94% to 97%) and 21% (95% CI, 17% to 25%) for the 2016 K-TIRADS. The sensitivity and specificity were 76% (95% CI, 74% to 79%) and 50% (95% CI, 49% to 52%) for the 2021 K-TIRADS1.5 (1.5-cm size cut-off for intermediate-suspicion nodules). The pooled unnecessary biopsy rates of the ACR-TIRADS, ATA system, EU-TIRADS, and 2016 K-TIRADS were 41% (95% CI, 32% to 49%), 65% (95% CI, 56% to 74%), 68% (95% CI, 60% to 75%), and 79% (95% CI, 74% to 83%), respectively. The unnecessary biopsy rate was 50% (95% CI, 47% to 53%) for the 2021 K-TIRADS1.5. Conclusion The unnecessary biopsy rate of the 2021 K-TIRADS1.5 was substantially lower than that of the 2016 K-TIRADS and comparable to that of the ACR-TIRADS. The 2021 K-TIRADS may help reduce potential harm due to unnecessary biopsies.