Lecanemab and donanemab have received full U.S. Food and Drug Administration (FDA) approval, and subsequently, lecanemab has been approved by the Korean FDA and it has recently entered commercial use in Korea. This has increased interest in anti-amyloid immunotherapy for Alzheimer’s disease. Anti-amyloid immunotherapy has shown potential to modify the progression of the disease by specifically binding to amyloid β, a key pathological product in Alzheimer’s disease, and eliminating accumulated amyloid plaques in the brain. However, this treatment can be accompanied by a side-effect, amyloid-related imaging abnormalities (ARIA), which requires periodic monitoring by MRI. It is crucial to detect ARIA and accurately assess the severity by radiology. The role of the radiologist is important in this context, requiring proficiency in basic knowledge of ARIA, and in diagnosing/evaluating ARIA. This review aims to comprehensively cover aspects of ARIA, including its definition, pathophysiology, incidence, risk factors, assessment of severity by radiology, differential diagnosis, and management.

The introduction of anti-amyloid therapies for Alzheimer’s disease (AD), such as lecanemab (Lequembi®), which was recently approved in Korea, necessitates careful monitoring for amyloid-related imaging abnormalities (ARIA) using brain MRI. To optimize ARIA monitoring in Korean clinical settings, the Korean Society of Neuroradiology (KSNR) and the Age and Neurodegeneration Imaging (ANDI) Study Group proposed MRI protocol recommendations on essential MR sequences, MRI acquisition parameters, timing and condition of MRI examinations, and essential details to provide a scientific basis for maximizing the safety and efficacy of AD treatment. A customized, standardized MRI protocol focusing on Korea’s healthcare environment can improve ARIA management and ensure patient safety through early detection of potential anti-amyloid therapy side effects, thereby enhancing treatment quality.

The anticancer drugs have evolved significantly, spanning molecular targeted therapeutics (MTTs), immune checkpoint inhibitors (ICIs), chimeric antigen receptor T-cell (CAR-T) therapy, and antibody-drug conjugates (ADCs). Complications associated with these drugs vary widely based on their mechanisms of action. MTTs that target angiogenesis can often lead to complications related to ischemia or endothelial damage across various organs, whereas non-anti-angiogenic MTTs present unique complications derived from their specific pharmacological actions. ICIs are predominantly associated with immunerelated adverse events, such as pneumonitis, colitis, hepatitis, thyroid disorders, hypophysitis, and sarcoid-like reactions. CAR-T therapy causes unique and severe complications including cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. ADCs tend to cause complications associated with cytotoxic payloads. A comprehensive understanding of these drug-specific toxicities, particularly using medical imaging, is essential for providing optimal patient care. Based on this knowledge, radiologists can play a pivotal role in multidisciplinary teams. Therefore, radiologists must stay up-to-date on the imaging characteristics of these complications and the mechanisms underlying novel anticancer drugs.

Clinical trials for chimeric antigen receptor (CAR) T-cell therapy are in the early stages but are expected to progress alongside new treatment approaches. This suggests that imaging will play an important role in monitoring disease progression, treatment response, and treatment-related side effects. There are, however, challenges that remain unresolved, regarding imaging in CAR T-cell therapy. We herein discuss the role of imaging, focusing on how tumor response evaluation varies according to cancer type and target antigens in CAR T-cell therapy. CAR T-cell therapy often produces rapid and significant responses, and imaging is vital for identifying side effects such as cytokine release syndrome and neurotoxicity. Radiologists should be aware of drug mechanisms, response assessments, and associated toxicities to effectively support these therapies. Additionally, this article highlights the importance of the Lugano criteria, which is essential for standardized assessment of treatment response, particularly in lymphoma therapies, and also explores other factors influencing imaging-based evaluation, including emerging methodologies and their potential to improve the accuracy and consistency of response assessments.

Background/Aims: Krebs von den Lungen-6 (KL-6) is associated with prognosis in patients with COVID-19. However, there is limited data on the correlation between the prognosis of COVID-19 and varying KL-6 levels at different time points. We investigated the optimal cutoff values of the initial and peak serum KL-6 levels to predict mortality and evaluated their correlation with mortality. Methods: This retrospective cohort study collected data on serially collected serum KL-6 levels in patients hospitalized with COVID-19 between October 2020 and January 2022 at a single tertiary hospital in South Korea. The area under the receiver operating characteristic curve and Youden index were used to determine the cutoff points for the initial and peak KL-6 levels that best predicted 30-day mortality. The association between the initial and peak KL-6 values was assessed by univariate and multivariate logistic regression models. Results: A total of 349 patients were included in this study. The mean initial and peak KL-6 levels were significantly higher in the non-survivor group than in the survivor group. The initial and peak KL-6 values that best predicted 30-day mortality were 491.85 U/mL and 660.05 U/mL, respectively. An initial KL-6 level greater than 491.85 U/mL and a peak KL-6 level greater than 660.05 U/mL were significantly associated with 30-day mortality. Conclusions The initial and peak levels of KL-6 were significantly associated with 30-day mortality in hospitalized patients with COVID-19. These findings suggest that serially monitoring blood KL-6 levels could be a valuable prognostic indicator for COVID-19.

Purpose: To identify the risk factors and effect of empirical glycopeptide on the failure of single arthroscopic debridement for septic knee arthritis in a native knee joint. Materials and Methods: Patients who underwent arthroscopic debridement for septic knee arthritis from March 2005 to December 2022 at one institution were included in this study. Demographic data, comorbidities, preoperative factors including history of previous surgery, history of injection, laboratory data including preoperative C-reactive protein (CRP) and white blood cell (WBC) count, isolated pathogens from synovial fluid culture, and Gachter stage were analyzed. Statistical analyses using univariate and logistic regression were performed. Results: Out of 132 patients, 17 patients (12.9%) had more than one additional arthroscopic debridement. History of diabetes mellitus (DM) (p<0.001), previous injection (p=0.041), isolated Staphylococcus aureus in synovial fluid (p=0.010), and high Gachter stage (p=0.002) were identified as risk factors, whereas age, history of previous knee surgery at the affected knee, CRP level, preoperative WBC, and preoperative neutrophil count of synovial fluid had no significant relation. Logistic regression analysis showed significant increase of risk in patients with DM [odds ratio (OR) 12.002, 95% confidence interval (CI) 3.243–44.418, p<0.001], previous injection history (OR 4.812, 95% CI 1.367–16.939, p=0.017), and isolation of Staphylococcus aureus in synovial fluid (OR 4.804, 95% CI 1.282–18.001, p=0.031) as independent risk factors for failure of infection eradication after single arthroscopic debridement. Conclusion Comorbidity of DM, history of previous injection, isolated Staphylococcus aureus in synovial fluid, and high Gachter stage were associated with a higher risk of failure to eradicate infection with a single arthroscopic procedure. Empirical glycopeptide administration also showed no significant benefit in reducing the risk of additional surgical procedures for infection control, suggesting against the routine administration of glycopeptide.

Background/Aims: Fexuprazan, a novel potassium-competitive acid blocker, was developed for treating acid-related disorders. Pharmacokinetic and pharmacodynamic properties of fexuprazan, unlike those of proton pump inhibitors, are independent of food effect. This study aims to evaluate differences in efficacy and safety of fexuprazan in patients with erosive esophagitis (EE) according to the timing of dosing. Methods: In this multicenter, open-label noninferiority study, patients who had typical reflux symptoms with endoscopically confirmed EE were randomized 1:1 to receive fexuprazan 40 mg daily 30 minutes before or after meal. Treatment was completed after 2 weeks or 4 weeks when healing was endoscopically confirmed. The primary endpoint was the proportion of patients with healed EE confirmed by endoscopy up to week 4. Safety endpoints included treatment-emergent adverse events (TEAEs). Results: In the prior-to-meal group (n = 89) and after-meal group (n = 86), 4-week EE healing rates were 98.77% and 100.00% (difference, 0.01%; 95% CI, –0.01% to 0.04%) and 2-week EE healing rates were 95.77% and 97.14% (difference, 0.01%; 95% CI, –0.05% to 0.07%), respectively. TEAEs were 9.78% and 8.70% in the prior-to-meal group and the after-meal group, respectively. Conclusions Non-inferiority analysis revealed that taking fexuprazan after meal was non-inferior to taking fexuprazan before meals in patients with EE. The frequency of adverse events was similar between the 2 study groups. The drug is safe and effective for healing EE regardless of the timing of dosing.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) represents a devastating and growing global threat, calling for new antibiotic treatments. In Korea, the challenge of treating CRAB is compounded by high nosocomial acquisition rates and limited availability of novel antibiotics. Minocycline, a semisynthetic tetracycline derivative, has been proposed as a therapeutic option for CRAB infections. Nonsusceptibility to minocycline may occur through the efflux pump, TetB. The prevalence of tetB in A. baumannii has increased, along with higher minocycline minimum inhibitory concentrations (MICs). We aimed to evaluate minocycline susceptibility rates in clinical strains of CRAB, and the association between tetB carriage and minocycline susceptibility across different genotypes. Materials and Methods: Representative CRAB blood isolates were collected from Asan Medical Center, Seoul.Minocycline susceptibility was assessed using the Clinical and Laboratory Standards Institute (CLSI) breakpoint (≤4 mg/L) and the proposed pharmacokinetics (PK)/pharmacodynamics (PD) breakpoint (≤1 mg/L). Tigecycline was used as a comparator, and its susceptibility breakpoint for Enterobacterales defined by EUCAST was applied (≤0.5 mg/L).The presence of tetB was detected by PCR, and multilocus sequence typing (MLST) was performed using seven housekeeping genes. Results: Of the 160 CRAB blood isolates, 83.8% were susceptible to minocycline by the CLSI criteria, and 50.6% were PK-PD susceptible by the PK-PD criteria. The minocycline minimum inhibitory concentration (MIC)50 /MIC90 was 1/8 mg/L. tetB was present in 49% of isolates and was associated with a higher minocycline MIC (MIC50/90 2/8 mg/L vs. 1/2 mg/L). No clear correlation was observed between tetB positivity and tigecycline MIC. Nine MLSTs were identified, with significant differences in tetB carriage rates between the major sequence types. Notably, ST191, associated with non-tetB carriage and greater susceptibility to minocycline, declined over the study period (P=0.004), while ST451, associated with tetB carriage, increased. Conclusion tetB was present in 49% of CRAB isolates and was associated with higher MICs and non-susceptibility by both CLSI and PK-PD criteria. However, absence of tetB was not a reliable predictor of minocycline PK-PD susceptibility. Additionally, shifts over time towards genotypes with reduced minocycline susceptibility were observed. Further research is needed to correlate these findings with clinical outcomes and identify additional resistance mechanisms.

Background: Meniscal scaffold implantation has been introduced as a treatment for meniscal injuries, but there is still no clear consensus on its clinical impact, including its chondroprotective effect. This review aimed to assess the chondroprotective effects, clinical outcomes, and survivorship of meniscal scaffold implantation compared to meniscectomy, as well as among different types of scaffolds. Methods: A comprehensive search strategy was performed on the databases of PubMed, Embase, Cochrane Library, and Google Scholar, encompassing articles published until June 1, 2024. Randomized controlled trials (RCT) and comparative studies published in English that reported results using collagen meniscal implant (CMI) and polyurethane meniscal scaffold for meniscal tear were included. Results: A total of 421 studies were initially identified across databases, and a systematic review was conducted on 8 studies involving 596 patients. Among the 5 studies that addressed the chondroprotective effect, none found that meniscal scaffolds had a higher chondroprotective effect compared to meniscectomy. In studies comparing CMI and meniscectomy, the Lysholm score results showed a mean difference (MD) range between –5.90 and –4.40. In the case of visual analog scale score, the MD ranged from –1.0 to 1.0. In studies comparing polyurethane meniscal scaffolds and CMI, the Tegner score results showed an MD range of –2.0 to 0.4. Conclusions There was no superiority in chondroprotective effects for both CMI and polyurethane meniscal scaffolds compared to meniscectomy. Although meniscal scaffolds may provide improvements in clinical outcomes, no clinically relevant differences were observed in comparison to meniscectomy. There are no discernible differences between the 2 types of scaffolds.