Background: Programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) inhibitors are effective treatments for non-small cell lung cancer (NSCLC), but their use can lead to severe pneumonitis. This study aims to evaluate the utility of Krebs von den Lungen-6 (KL-6) for predicting and diagnosing PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. Methods: We conducted a prospective observational study at a university-affiliated tertiary hospital in Korea from February 2022 to June 2023. Baseline KL-6 levels were measured immediately before initiating PD-1/PD-L1 inhibitor therapy. In patients who developed pneumonitis, KL-6 levels were monitored every 1–2 weeks from the onset of pneumonitis. For patients without pneumonitis, KL-6 levels were measured every 6 weeks. We compared clinical characteristics and serial KL-6 levels between the pneumonitis and non-pneumonitis groups. Results: Eighteen patients were enrolled, with 11 developing pneumonitis. Baseline KL-6 levels did not significantly differ between the two groups (261 U/mL in the pneumonitis group vs. 373 U/mL in the non-pneumonitis group, p=0.375). In the pneumonitis group, KL-6 levels generally showed an upward trend, with a median of 412 U/mL at pneumonitis onset. Conversely, KL-6 levels in the non-pneumonitis group showed no clear overall change. Conclusion In this pilot study, baseline KL-6 was not clearly linked to PD-1/PD-L1 inhibitor-related pneumonitis in NSCLC patients. However, increases in KL-6 levels post-baseline were more frequently observed in patients who developed pneumonitis, including cases of all-cause pneumonitis.

Background: The Act on Decisions on Life-Sustaining Treatment (LST) has been implemented in Korea since 2018, yet data on its application in neurocritical care units remain scarce. This study aimed to evaluate the clinical characteristics and outcomes of LST withdrawal or withholding in the neurocritical care unit. Methods: This study was a retrospective analysis conducted at a tertiary university hospital in Busan, South Korea. Among patients admitted to the neurocritical care unit between February 2018 and August 2023, those with documented decisions for LST withdrawal or withholding were enrolled. Demographic and clinical characteristics, underlying and combined conditions, reasons for LST decisions, measures taken, and time from LST withdrawal to death were extracted from medical records. Results: A total of 69 patients were included, with a median age of 67 years, and 38 (55%) were male. Cerebrovascular disease (62%) and traumatic brain injury (22%) were the most common underlying diagnoses. The primary reason for LST decisions was irreversible neurological damage (71%), followed by systemic complications (19%). Mechanical ventilation cessation (91%) and extubation (86%) were most frequently used measures for LST withdrawal. The median time from LST withdrawal to death was 22 minutes. Conclusions Our study demonstrates that LST decisions in the neurocritical care unit predominantly occur among patients with cerebrovascular disease or traumatic brain injury, mostly triggered by neurological deterioration. Most patients died shortly after withdrawal. These findings provide important insight into current LST withdrawal practices in neurocritical care and may assist clinical and ethical decision making in similar settings.

Radical cholecystectomy is the standard procedure for gallbladder (GB) cancer, offering the possibility of cure. Many surgeons have increasingly expanded surgical indications following the growing trend of robotic surgery in hepatobiliary and pancreatic surgery. This study presents our experience with several robotic single-port (SP) plus one-port radical cholecystectomies using the da Vinci system (Intuitive Surgical). Data from five patients who underwent robotic SP radical cholecystectomy for GB cancer between April 2024 and December 2024 were retrospectively reviewed. All patients presented with imaging findings suggestive of localized GB cancer (T2 or lower). The median operative time was 145 minutes (range, 121–153 minutes), and the median number of harvested lymph nodes was five (range, five to eight). The median hospital stay after surgery was 6 days (range, 6–7 days), with no major complications reported. Robotic SP radical cholecystectomy is a safe and feasible option for GB cancer.

The recent approval of trastuzumab deruxtecan for human epidermal growth factor receptor 2 (HER2)–low and HER2-ultralow breast cancer mandates an adequate assessment of these categories. Methods: Seven breast pathologists from the Breast Pathology Study Group of the Korean Society of Pathologists held an on-site expert consensus meeting. Fifteen sets of virtual whole slide images (WSI) of hematoxylin and eosin stain and HER2 immunohistochemistry were provided. The pathologists were given 60 minutes to submit their diagnosis of HER2 expression into null, ultralow, 1+, 2+, or 3+. Afterwards, in-depth discussion and consensus diagnoses were made by real-time visualization of the WSI. Results: After the consensus meeting, unanimous 100% agreements were seen only in five (33.3%) of the examined cases, which consisted of three 1+ cases and two 2+ cases. Two cases (13.3%) had mild disagreement, with only one pathologist’s disagreement. Of note, eight cases (53.3%) showed significant disagreement, defined by more than two pathologists’ disagreement. All HER2-null cases were reclassified as ultralow after consensus review, suggesting potential widespread underclassification of ultralow cases in clinical practice. Conclusions: Experts had significant discrepancies in interpreting HER2-low/ultralow status. It is important to assess if the distinction between HER2-low and ultralow is strictly required and if HER2-null breast cancer exists in reality.

Background: The World Health Organization has declared the end of the coronavirus disease 2019 (COVID-19) public health emergency. However, this did not indicate the end of COVID-19. Several months after the infection, numerous patients complain of respiratory or nonspecific symptoms; this condition is called long COVID. Even patients with mild COVID-19 can experience long COVID, thus the burden of long COVID remains considerable. Therefore, we conducted this study to comprehensively analyze the effects of long COVID using multi-faceted assessments. Materials and Methods: We conducted a prospective cohort study involving patients diagnosed with COVID-19 between February 2020 and September 2021 in six tertiary hospitals in Korea. Patients were followed up at 1, 3, 6, 12, 18, and 24 months after discharge. Long COVID was defined as the persistence of three or more COVID-19-related symptoms. The primary outcome of this study was the prevalence of long COVID after the period of COVID-19. Results: During the study period, 290 patients were enrolled. Among them, 54.5 and 34.6% experienced long COVID within 6 months and after more than 18 months, respectively. Several patients showed abnormal results when tested for post-traumatic stress disorder (17.4%) and anxiety (31.9%) after 18 months. In patients who underwent follow-up chest computed tomography 18 months after COVID-19, abnormal findings remained at 51.9%. Males (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.53; P=0.004) and elderly (OR, 1.04; 95% CI, 1.00–1.09; P=0.04) showed a significant association with long COVID after 12–18 months in a multivariable logistic regression analysis. Conclusion Many patients still showed long COVID after 18 months post SARS-CoV-2 infection. When managing these patients, the assessment of multiple aspects is necessary.

Background: and Purpose Treatments for neuromyelitis optica spectrum disorder (NMOSD) such as eculizumab, ravulizumab, satralizumab, and inebilizumab have significantly advanced relapse prevention, but they remain expensive. Rituximab is an off-label yet popular alternative that offers a cost-effective solution, but its real-world efficacy needs better quantification for guiding the application of newer approved NMOSD treatments (ANTs). This study aimed to determine real-world rituximab failure rates to anticipate the demand for ANTs and aid in resource allocation. Methods: We conducted a nationwide retrospective study involving 605 aquaporin-4-antibody-positive NMOSD patients from 22 centers in South Korea that assessed the efficacy and safety of rituximab over a median follow-up of 47 months. Results: The 605 patients treated with rituximab included 525 (87%) who received continuous therapy throughout the follow-up period (median=47 months, interquartile range=15–87 months). During this period, 117 patients (19%) experienced at least 1 relapse. Notably, 68 of these patients (11% of the total cohort) experienced multiple relapses or at least 1 severe relapse.Additionally, 2% of the patients discontinued rituximab due to adverse events, which included severe infusion reactions, neutropenia, and infections. Conclusions This study has confirmed the efficacy of rituximab in treating NMOSD, as evidenced by an 87% continuation rate among patients over a 4-year follow-up period. Nevertheless, the occurrence of at least one relapse in 19% of the cohort, including 11% who experienced multiple or severe relapses, and a 2% discontinuation rate due to adverse events highlight the urgent need for alternative therapeutic options.

Background: s/Aims: Radiofrequency ablation (RFA) is widely employed for managing recurrent hepatocellular carcinoma (HCC) following transarterial chemoembolization (TACE). However, local tumor progression (LTP) after treatment remains a significant challenge. This study evaluates the efficacy of saline-perfused bipolar RFA using twin internally cooled-perfusion (TICP) electrodes in managing recurrent HCC post-TACE. Methods: Between September 2017 and January 2019, 100 patients with 105 nodules (mean diameter, 1.6±0.5 cm) were prospectively enrolled. Bipolar RFA with TICP electrodes was performed under ultrasound-computed tomography/magnetic resonance fusion guidance. The primary outcome was the 2-year cumulative incidence of LTP. Results: The technical success and technique efficacy rates were 100% and 97%, respectively. During a median follow-up period of 34.0 months (range, 3-41), the estimated LTP rates were 13.3% at 1 year and 17.7% at 2 years. Progression-free survival rates were 37.8% and 27.7% at 1 year and 2 years, respectively. Conclusions Saline-perfused bipolar RFA using TICP electrodes demonstrates promising results for recurrent HCC after TACE, achieving high technical success and effective local tumor control rates.

Purpose: The study aimed to compare the differences in patency between helical interwoven nitinol stents and balloon angioplasty in patients with arteriovenous graft (AVG) malfunction caused by venous anastomosis stenosis. Materials and Methods: This retrospective study included patients who underwent helical interwoven nitinol stent placement (n = 15) or balloon angioplasty (n = 25) between January 2016 and September 2021. The primary and secondary patency rates were compared between the two groups. Results: Dialysis was possible post-intervention in all patients who showed no specific complications, including stent fracture. The average primary patency of the stent placement group was longer than that of the balloon angioplasty group but did not differ significantly (8.5 vs. 6.3 months, p = 0.319). The mean secondary patency period was 17.6 months in the stent placement group, which was shorter than that in the balloon angioplasty group (18.8 months); however, this difference was also not statistically significant (p = 0.660). Conclusion Helical interwoven nitinol stents could maintain patency in patients with AVG malfunction caused by venous anastomosis stenosis, but they did not improve patency compared to balloon angioplasty.