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.

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: Extensive spinal fusion inevitably results in loss of mobility, which may induce stiffness-related disability (SRD) during activities of daily living. Few studies have examined SRD after surgical correction for adolescent idiopathic scoliosis (AIS). This study aimed to investigate SRD following surgical treatment in AIS patients particularly with respect to the lowest instrumented vertebra (LIV). Methods: Patients who underwent surgical correction for AIS between 2014 and 2021 and were followed up for 2 years were included. The degree of SRD was evaluated using the Stiffness-Related Disability Index (SRDI), which consists of 4 categories, each containing 3 questions, giving a total of 12 components of the questionnaire. The SRDI scores were compared according to the LIV level. Correlation analysis was performed to examine the relationship between the SRDI and legacy health-related quality of life (HRQOL) measurements. Results: This study included 174 patients (47 men and 127 women) with a mean age of 13.8 years. Among the 12 items of the SRDI, the scores of 9 items showed a significant increase after surgery. The total sum of the SRDI scores also significantly increased after surgery. Pearson correlation analysis showed that the SRDI scores were significantly correlated with Oswestry disability index, nearly all domains, and the total sum of Scoliosis Research Society-22 questionnaire, and 36-Item Short Form Survey.No differences in the SRDI score were found among cases with the LIV between T12 and L3. However, the SRDI scores of patients with LIV at L4 were significantly higher than those of patients with other LIV levels. Conclusions Various degrees of SRD occurred after spinal fusion for AIS. The SRDI was significantly correlated with the HRQOL measurements. The SRDI score was highest in patients with the LIV at L4 when compared to those with other LIV levels. Fusion can be safely extended to L3 without significantly increasing SRD.

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.

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.