Objectives: . Differentiated thyroid cancer (DTC) has a favorable prognosis. However, indeterminate lymph nodes (LNs) are common, making it challenging to distinguish recurrent from persistent DTC. Previous studies have not specifically compared the prognosis between recurrent and persistent DTC. Therefore, we aimed to compare prognosis and oncologic characteristics between these two groups. Methods: . This retrospective cohort study was conducted at a single tertiary care institution and included 265 patients with DTC (recurrent, 109; persistent, 156) who underwent reoperation between November 1, 1999, and August 31, 2018, for structural disease. Patients with distant metastasis at the time of initial diagnosis were excluded. Clinical and oncological characteristics, patterns of LN metastasis, disease-free survival (DFS), and overall survival (OS) were compared between the two groups. For DFS, time zero was defined as the date of the second operation. Results: . Recurrent DTC had a higher incidence of central LN metastasis (P=0.003), infield recurrence (P<0.001), and distant metastasis (P<0.001). In contrast, persistent DTC more frequently exhibited lateral LN metastasis (P=0.003) and outfield recurrence (P<0.001). The most common site of neck LN metastasis was ipsilateral level VI/VII (51.4%) in recurrent DTC and ipsilateral level IV (43.0%) in persistent DTC. Ten-year DFS was significantly lower in recurrent DTC than in persistent DTC (41.0% vs. 67.9%; P<0.001). Recurrent DTC, older age, a higher number of metastatic LNs at the second operation (first reoperation), and R1/R2 resection at the second operation were associated with decreased DFS. OS did not significantly differ between recurrent and persistent DTC (P=0.160). Conclusion . Recurrent DTC is associated with poorer DFS than persistent DTC, although OS does not significantly differ between the two groups.

Objective: To evaluate the feasibility of cerebral computed tomography angiography (CTA) obtained with reduced iodine and low radiation at 70 kVp and the effect of deep learning-based augmented contrast enhancement (DL-ACE) and denoising (DL-DN) algorithms on the CTA quality. Materials and Methods: In this prospective study, 47 healthy volunteers (male:female, 31:16; mean age ± standard deviation, 57.8 ± 10.9 years) were randomly assigned to one of three CTA protocols: Group A (n = 16; 100 kVp, 40 mL of 350 mgI/mL), Group B (n = 16; 70 kVp, 40 mL of 270 mgI/mL), and Group C (n = 15; 70 kVp, 28 mL of 270 mgI/mL [ultralow iodine]), with an injection rate of 2.5 mL/s for all. Images were reconstructed using filtered back projection (FBP), and images in Groups B and C were additionally reconstructed using DL-ACE and DL-DN. Arterial attenuation, image noise, contrast-to-noise ratio (CNR), and subjective image quality were compared among five image sets. Results: Compared with Group A, Groups B and C received 23.7% lower radiation doses. With FBP, arterial attenuation was significantly higher in Groups B (435.8 ± 50.2 Hounsfield units [HU]) and C (391.8 ± 52.1 HU) than in Group A (321.1 ± 47.4 HU) (P < 0.001), while CNR did not differ significantly (Group A, 19.9 ± 4.7; Group B, 20.3 ± 3.8; and Group C, 18.4 ± 4.6) due to higher image noise in Groups B and C. After applying DL-ACE and DL-DN in Groups B and C, arterial attenuation increased by 45.4% and image noise decreased by 34.5%, resulting in significantly higher arterial attenuation, CNR, and subjective image quality compared with Group A (P < 0.001). Conclusion Cerebral CTA at 70-kVp using ultralow iodine enhanced arterial attenuation but increased image noise compared with the 100-kVp CTA protocol. DL-ACE and DL-DN significantly increased arterial attenuation and reduced image noise, resulting in higher CNR and better subjective image quality.

Middle meningeal arteriovenous fistulas (MMAVFs) are known as rare diseases, often associated with head trauma, with idiopathic cases being exceedingly uncommon. Here, we present a clinical case of spontaneous and simultaneous bilateral MMAVFs in a 37-year-old woman. She presented with persistent pulsatile tinnitus but no history of head trauma. Bilateral MMAVFs were identified via Time-of-Flight Magnetic Resonance Angiography. Subsequent digital subtraction angiography revealed a fistula between the middle meningeal artery (MMA) and middle meningeal vein (MMV) without definite intracranial venous reflux. We had planned coil embolization via a trans-arterial approach for both sides. Remarkably, after six days, the right-sided MMAVF observed in the previous external carotid artery (ECA) angiogram disappeared spontaneously. The left-sided MMAVF was successfully treated with coil embolization, achieving complete obliteration of fistula flow. Postoperatively, the patient’s pulsatile tinnitus disappeared, and she was discharged without medication. There are a few possible mechanisms of spontaneous MMAVFs, such as middle meningeal artery aneurysm and trivial head trauma. Trans-arterial embolization with coils appears to be an effective and safe treatment option for complete obliteration of fistula flow.

Background/Aims: The Korean guidelines for Helicobacter pylori treatment were revised in 2020, however, the extent of adherence to these guidelines in clinical practice remains unclear. Herein, we initiated a prospective, nationwide, multicenter registry study in 2021 to evaluate the current management of H.pylori infection in Korea. Methods: This interim report describes the adherence to the revised guidelines and their impact on firstline eradication rates. Data on patient demographics, diagnoses, treatments, and eradication outcomes were collected using a web-based electronic case report form. Results: A total of 7,261 patients from 66 hospitals who received first-line treatment were analyzed.The modified intention-to-treat eradication rate for first-line treatment was 81.0%, with 80.4% of the prescriptions adhering to the revised guidelines. The most commonly prescribed regimen was the 14-day clarithromycin-based triple therapy (CTT; 42.0%), followed by tailored therapy (TT; 21.2%), 7-day CTT (14.1%), and 10-day concomitant therapy (CT; 10.1%). Time-trend analysis demonstrated significant increases in guideline adherence and the use of 10-day CT and TT, along with a decrease in the use of 7-day CTT (all p<0.001). Multivariate logistic regression analysis revealed that guideline adherence was significantly associated with first-line eradication success (odds ratio, 2.03; 95% confidence interval, 1.61 to 2.56; p<0.001). Conclusions The revised guidelines for the treatment of H. pylori infection have been increasingly adopted in routine clinical practice in Korea, which may have contributed to improved first-line eradication rates. Notably, the 14-day CTT, 10-day CT, and TT regimens are emerging as the preferred first-line treatment options among Korean physicians.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Background: The Korean National Cancer Screening Program (NCSP) for gastric cancer requires economic evaluation due to the low sensitivity of upper gastrointestinal series (UGIs) and the associated low cancer survival rate. This study aimed to ascertain the most cost-effective strategy for the NCSP. Methods: The hypothetical target population of this study was aged 40 years or older, and no actual participants were involved. Markov simulation models were constructed for 25 strategies, combinations of 1) screening methods (UGIs or endoscopy vs. endoscopy-only), 2) screening intervals (one, two, or three-year), and 3) upper age limit of screening (69, 74, 79 years old, or “no limit”). Costs, utility, and other input parameters were extracted from various databases and previous studies. Cost-utility, sensitivity, and scenario analyses were conducted. Results: The endoscopy-only strategy with a three-year interval with an upper age limit of 69 was the most cost-effective strategy with an incremental cost-utility ratio of KRW 13,354,106 per quality-adjusted life years. According to the probabilistic sensitivity analysis, the uncertainty of the result was significantly small. Scenario analysis is showed that as the screening rate increased, the endoscopy-only strategy saved more costs compared to the current NCSP. Therefore, it is important to maintain a high screening rate when altering the NCSP strategy. Conclusion Endoscopy-only screening was more cost-effective method than UGIs for the NCSP. Furthermore, a three-year interval with an upper-age limit of 69 years was the most cost-effective strategy. Efforts to improve cost-effective screening guidelines will support the efficient use of medical resources. Additionally, maintaining a higher screening rate may maximize the impact of the modification in strategy on cost-effectiveness.

Background: The Korean National Cancer Screening Program (NCSP) for gastric cancer requires economic evaluation due to the low sensitivity of upper gastrointestinal series (UGIs) and the associated low cancer survival rate. This study aimed to ascertain the most cost-effective strategy for the NCSP. Methods: The hypothetical target population of this study was aged 40 years or older, and no actual participants were involved. Markov simulation models were constructed for 25 strategies, combinations of 1) screening methods (UGIs or endoscopy vs. endoscopy-only), 2) screening intervals (one, two, or three-year), and 3) upper age limit of screening (69, 74, 79 years old, or “no limit”). Costs, utility, and other input parameters were extracted from various databases and previous studies. Cost-utility, sensitivity, and scenario analyses were conducted. Results: The endoscopy-only strategy with a three-year interval with an upper age limit of 69 was the most cost-effective strategy with an incremental cost-utility ratio of KRW 13,354,106 per quality-adjusted life years. According to the probabilistic sensitivity analysis, the uncertainty of the result was significantly small. Scenario analysis is showed that as the screening rate increased, the endoscopy-only strategy saved more costs compared to the current NCSP. Therefore, it is important to maintain a high screening rate when altering the NCSP strategy. Conclusion Endoscopy-only screening was more cost-effective method than UGIs for the NCSP. Furthermore, a three-year interval with an upper-age limit of 69 years was the most cost-effective strategy. Efforts to improve cost-effective screening guidelines will support the efficient use of medical resources. Additionally, maintaining a higher screening rate may maximize the impact of the modification in strategy on cost-effectiveness.

Background: The Korean National Cancer Screening Program (NCSP) for gastric cancer requires economic evaluation due to the low sensitivity of upper gastrointestinal series (UGIs) and the associated low cancer survival rate. This study aimed to ascertain the most cost-effective strategy for the NCSP. Methods: The hypothetical target population of this study was aged 40 years or older, and no actual participants were involved. Markov simulation models were constructed for 25 strategies, combinations of 1) screening methods (UGIs or endoscopy vs. endoscopy-only), 2) screening intervals (one, two, or three-year), and 3) upper age limit of screening (69, 74, 79 years old, or “no limit”). Costs, utility, and other input parameters were extracted from various databases and previous studies. Cost-utility, sensitivity, and scenario analyses were conducted. Results: The endoscopy-only strategy with a three-year interval with an upper age limit of 69 was the most cost-effective strategy with an incremental cost-utility ratio of KRW 13,354,106 per quality-adjusted life years. According to the probabilistic sensitivity analysis, the uncertainty of the result was significantly small. Scenario analysis is showed that as the screening rate increased, the endoscopy-only strategy saved more costs compared to the current NCSP. Therefore, it is important to maintain a high screening rate when altering the NCSP strategy. Conclusion Endoscopy-only screening was more cost-effective method than UGIs for the NCSP. Furthermore, a three-year interval with an upper-age limit of 69 years was the most cost-effective strategy. Efforts to improve cost-effective screening guidelines will support the efficient use of medical resources. Additionally, maintaining a higher screening rate may maximize the impact of the modification in strategy on cost-effectiveness.