Background and Objectives: Studies investigating the correlation between papillary thyroid carcinoma (PTC) tumor size and the prevalence of the B-type Raf kinase (BRAF) mutation have yielded conflicting results. Therefore, we evaluated the prevalence of BRAF mutation according to tumor size in a large cohort of PTC patients to clarify this association. Materials and Methods: We retrospectively analyzed 6,438 patients with surgically diagnosed classic PTC between January 2009 and December 2017 at Samsung Medical Center, Seoul, Republic of Korea.During the study period, BRAF mutation testing was attempted on all fine-needle aspiration specimens, except for a small number of inadequate specimens. All other histologic subtypes were excluded. The prevalence of BRAF mutation was assessed based on tumor size, and further analyzed by age group and sex according to tumor size. Results: The overall prevalence of BRAF mutation was 79.2%. When PTCs ≤1 cm were excluded, the prevalence was 77.2%. The prevalence significantly decreased with increasing tumor size (p for trend ＜0.001). It was significantly higher in men than in women (p=0.013), but did not differ by age. The inverse correlation between tumor size and prevalence was prominent in patients aged 20-49 years but was less distinct in those aged 50 years and older. Conclusion In this large cohort of patients with PTC, the prevalence of BRAF mutation significantly decreased with increasing tumor size. These findings suggest that BRAF mutation is enriched in smaller surgically treated classic PTCs and may provide a hypothesis-generating clue regarding its role in early PTC development, although selection bias cannot be excluded.

Purpose: This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control. Methods: We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR. Results: Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37). Conclusion Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.

Purpose: To report the clinical utility of the Barrett True-K formula in predicting multifocal intraocular lens (IOL) power in a patient with corneal deformation caused by radial keratotomy (RK), where postoperative refractive power prediction is challenging.Case summary: A 61-year-old male who underwent RK 30 years ago presented for cataract surgery. Slit-lamp examination showed eight RK incisions in each eye. Refractive error was +3.25 D sph; -1.75 D cyl, axis 70 in the right eye and +2.75 D sph; -1.00 D cyl, axis 110 in the left. Uncorrected visual acuity was 0.32 in the right eye and 0.63 in the left. IOL power was calculated using the Barrett True-K formula on the IOLMaster 700, with a target refraction of -0.25 D, and a multifocal IOL was implanted. Six months after cataract surgery, both eyes achieved a fraction close to emmetropia, with best corrected visual acuity of 0.63 in the right eye and 1.0 in the left. No significant refractive shifts or other complications were observed during surgery or 6-month follow-up. Conclusions The Barrett True-K formula, which measures the actual corneal refractive power to compensate for corneal deformation, is expected to be clinically useful for multifocal IOL implantation during cataract surgery in eyes after RK.

Purpose: To compare the clinical outcomes of early pars plana vitrectomy versus intravitreal antibiotic injection in patients who developed infectious endophthalmitis after cataract surgery. Methods: The medical records of patients diagnosed with infectious endophthalmitis following cataract surgery between 2006 and 2023, whose initial best-corrected visual acuity (BCVA) values were 0.48 to 2.3 in LogMAR units, were retrospectively reviewed. Final BCVA and the degree of visual improvement were compared between early vitrectomy and intravitreal antibiotic injection-only groups. Additionally, patients who underwent delayed vitrectomy within 3 days after the initial intravitreal antibiotic injection (delayed vitrectomy group) were separately analyzed and compared. Results: At 6 months post-treatment, the mean BCVA values were significantly better in the early vitrectomy group (0.37 ± 0.27) than in the injection group (1.02 ± 0.81) (p = 0.004); the early vitrectomy group also had greater visual improvement at both 1 week and 6 months after treatment (p = 0.004, p < 0.001). Compared to the delayed vitrectomy group, the early group demonstrated significantly greater visual improvement at both time points (p = 0.010, p = 0.001). The retreatment rate was higher in the injection group than in the early vitrectomy group. Conclusions In patients who developed infectious endophthalmitis after cataract surgery and had an initial visual acuity between light perception or better and 20/60, early vitrectomy resulted in better visual outcomes compared to intravitreal antibiotic injection alone or delayed vitrectomy.

Background/Aims: Patients with atrial fibrillation (AF) and end-stage kidney disease (ESKD) require careful anticoagulation because thrombotic and bleeding risks are both elevated. We evaluated the efficacy and safety of warfarin, direct oral anticoagulants (DOACs), and no anticoagulation in Korean patients with ESKD and AF. Methods: In this multicenter retrospective study, we included 933 patients with ESKD and nonvalvular AF treated between 2010 and 2023. Patients were assigned to three groups by initial treatment: no anticoagulation (n = 604), warfarin (n = 197), or DOACs (n = 132). The primary efficacy outcome was ischemic stroke or systemic embolism (IS/SE); the primary safety outcome was major bleeding (MB). Secondary outcomes were intracranial hemorrhage (ICH), gastrointestinal bleeding (GIB), and all-cause mortality. Inverse probability of treatment weighting was used to adjust for confounding. Results: Both warfarin (adjusted hazard ratio [aHR], 0.55) and DOACs (aHR, 0.36) significantly reduced the risk of IS/SE compared with no anticoagulation. However, warfarin increased MB risk compared with no anticoagulation (aHR, 2.69), including ICH and GIB. DOACs also increased MB risk versus no anticoagulation (aHR, 1.37), driven primarily by ICH. Compared with warfarin, DOACs showed a lower MB risk (aHR, 0.51). Both warfarin and DOACs reduced all-cause mortality relative to no anticoagulation (aHR, 0.53 and 0.57, respectively). Conclusions Among Korean patients with ESKD and AF, both warfarin and DOACs reduced IS/SE but increased MB. Given their lower MB risk than warfarin, DOACs may be preferable for anticoagulation in this high-risk population.

Background/Aims: Gastric antral vascular ectasia (GAVE) is a rare but important cause of gastrointestinal (GI) bleeding. The clinical course of GAVE is not well-known, and recurrent bleeding from GAVE is a therapeutic challenge. Therefore, we investigated the clinical course of GAVE and identified the risk factors for bleeding from it. Methods: We retrospectively reviewed the records of patients diagnosed with GAVE using upper GI endoscopy at Asan Medical Center between January 2004 and December 2019 and evaluated the clinical course and risk factors for bleeding from GAVE. Results: Of the 348 patients (mean age, 62.3 ± 10.7 years; male, 62%), bleeding from GAVE occurred in 123 (35%) patients during follow-up (median, 17.3 months; interquartile range [IQR], 4.2–46.6). GI bleeding from GAVE was significantly associated with Child–Pugh class B or C liver cirrhosis (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.57–4.16), chronic kidney disease (CKD) (OR, 2.77; 95% CI, 1.52–5.07), use of antithrombotic agents (OR, 2.34; 95% CI, 1.13–4.82), and involvement of the duodenal bulb (OR, 3.21; 95% CI, 1.76–5.86). Rebleeding occurred in 39 of 123 patients (32%), in whom CKD (OR, 2.55; 95% CI, 1.12–5.81) was significantly associated with rebleeding. Endoscopic hemostasis was most commonly performed using argon plasma coagulation, and the median number of endoscopic hemostasis performed was 2 (IQR, 1–3). Conclusions A careful follow-up for bleeding is needed in GAVE patients with liver cirrhosis, CKD, use of antithrombotic agents, and duodenal bulb involvement.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

This video demonstrates the surgical technique of percutaneous endoscopic debridement and drainage (PEDD) for infectious spondylodiscitis performed under local anesthesia. Two representative cases are presented. The first case underwent transforaminal PEDD for L2–3 infectious spondylodiscitis, and the second case underwent combined transforaminal PEDD and drainage of a psoas abscess. In both cases, needle insertion was guided by C-arm fluoroscopy, followed by root block, discography, serial dilation, and insertion of a 3.7-mm endoscope. Under endoscopic visualization, necrotic disc material and infected granulation tissue were removed, and samples were collected for culture and biopsy. The procedure also enabled safe placement of a drainage catheter into the abscess cavity. Postoperatively, one patient improved with intravenous antibiotics after identification of Streptococcus constellatus, while the other was diagnosed with tuberculous spondylodiscitis and treated with antituberculosis therapy. Both patients showed gradual improvement in back pain and normalization of inflammatory markers. This video provides a detailed step-by-step guide to PEDD, highlighting its diagnostic and therapeutic advantages in infectious spondylodiscitis, as well as its educational value for surgeons learning full-endoscopic spine surgery.