1.Clinical Features and Prognosis of MEK Inhibitor–associated Retinopathy: A Case Series
Tae Hwan KIM ; Christopher Seungkyu LEE ; Suk Ho BYEON ; Sung Soo KIM ; Yong Joon KIM
Journal of Retina 2026;11(1):50-59
Purpose:
To investigate the clinical characteristics, onset timing, and anatomical and functional outcomes of MEK inhibitor–associated retinopathy (MEKAR) in Korean patients receiving systemic MEK inhibitor therapy.
Methods:
This retrospective study included 16 patients diagnosed with MEKAR between January 2011 and August 2025. Best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (CT), and optical coherence tomography (OCT) findings were evaluated at baseline, at MEKAR onset, and at final follow-up.
Results:
Mean age was 57.8 ± 10.6 years, with a male predominance (68.8%). Colorectal cancer was the most common primary malignancy (56.3%), followed by lung cancer and malignant melanoma (18.7% each). MEKAR developed after a median of 3.3 weeks (IQR, 1.9–4.4 weeks) following therapy initiation, and the median time to initial improvement was 2.4 weeks (IQR, 1.3–8.1 weeks). At onset, 62.6% of patients reported ocular symptoms, while 37.4% were asymptomatic. OCT showed reversible retinal changes, most commonly ellipsoid zone thickening (68.8%) and focal subretinal fluid (43.8%), all of which resolved completely. CMT increased transiently at onset compared with baseline (p = 0.002) and normalized at final follow-up (p < 0.001), with no baseline–final difference (p = 0.489). CT remained stable (p = 0.159). BCVA was preserved, with a median of 0.00 logMAR at baseline, onset and final follow-up. Patients undergoing dose modification or interruption showed faster improvement than those continuing therapy (median, 9 vs. 81 days; p = 0.004). One patient showed multiple recurrent episodes, all of which resolved without visual deterioration.
Conclusions
MEKAR developed early after treatment initiation and followed a transient, fully reversible course with preserved visual function. Although dose modification accelerated anatomical recovery, long-term outcomes remained favorable even with continued therapy, supporting close monitoring and individualized management rather than routine interruption, particularly in mild or asymptomatic cases.
2.Lumbar spinal stenosis: current concept of management
Ji-Won KWON ; Kyung-Soo SUK ; Seong-Hwan MOON ; Si-Young PARK ; Namhoo KIM ; Sub-Ri PARK ; Jae-Won SHIN ; Hak-Sun KIM ; Byung Ho LEE
Asian Spine Journal 2026;20(1):143-157
Lumbar spinal stenosis (LSS) is a common degenerative spinal condition where spinal canal narrowing causes symptoms such as neurogenic claudication, radiculopathy, and lower back pain. While non-operative and surgical approaches yield similar long-term outcomes, surgical intervention—particularly decompression—can provide earlier symptom relief, functional recovery, and fall prevention in selected patients with refractory symptoms. Recent advancements in surgical technologies and image guidance have brought about a paradigm shift in LSS management. Biportal endoscopic spine surgery (BESS) has gained global traction as a minimally invasive alternative to traditional decompression methods, offering superior visualization, less soft tissue damage, shorter hospital stays, and faster recovery. High-quality studies, including randomized controlled trials, have shown promising outcomes for this technique. Furthermore, the integration of navigation systems, robot-assisted instrumentation, and artificial intelligence (AI)-driven diagnostics and surgical planning tools is transforming spinal surgery by enhancing precision in preoperative evaluation and intraoperative execution. These innovations enable accurate targeting, reduce complications, and improve reproducibility across diverse surgical settings. This review provides an updated overview of LSS, covering its pathophysiology, clinical assessment, diagnosis, and treatment. Special emphasis is placed on the growing role of BESS and the transformative impact of digital technologies such as navigation, robotics, and AI in the evolving landscape of spinal stenosis care.
3.Association of Sleep Patterns with the Development of Idiopathic Scoliosis:A Nationwide Pediatric Cohort Study
Weonmin CHO ; Soo-Bin LEE ; Sahyun SUNG ; Ji-Won KWON ; Seong-Hwan MOON ; Kyung-Soo SUK ; Hak-Sun KIM ; Si-Young PARK ; Byung Ho LEE
Clinics in Orthopedic Surgery 2026;18(1):78-86
Background:
The etiology of adolescent idiopathic scoliosis is multifactorial, and the influence of lifestyle factors such as sleep is not clearly understood. Differences in scoliosis incidence between urban and rural areas have been reported, but the contributing factors remain unclear. Therefore, this study investigated the association between sleep patterns and the incidence of idiopathic scoliosis and explored whether these patterns contribute to the observed urban-rural disparity.
Methods:
This retrospective study utilized data from the Korea Children and Youth Panel Survey (2010–2016) and the Health Insurance Review and Assessment Service for 4,693 students (age, 7–18 years). Various lifestyle factors including sleep patterns, learning time, and activity times, were compared between urban and rural areas, and a correlation analysis was performed between these factors and the age-specific incidence of idiopathic scoliosis.
Results:
Urban students, who exhibited higher idiopathic scoliosis incidence rates, tended to have later bedtimes and shorter total sleep durations than rural students. Longer learning hours were also observed in urban areas. Significant correlations were found between idiopathic scoliosis incidence and bedtime (p = 0.031), total sleep time (p = 0.026), and changes in total sleep time (p = 0.011).
Conclusions
Our findings indicate that later bedtimes and shorter sleep durations may contribute to idiopathic scoliosis development in children and adolescents. The higher idiopathic scoliosis incidence in urban students than in rural students could be partially explained by these sleep pattern differences, highlighting the need for further research into the role of sleep in scoliosis onset and prevention.
4.Molecular determinants of outcome to gemcitabine, cisplatin, and nab-paclitaxel in patients with advanced biliary tract cancer
Daeseong KIM ; Nam Suk SIM ; Seonjeong WOO ; Min Hwan KIM ; Choong-kun LEE ; Seung Soo HONG ; Sung Hyun KIM ; Ho Kyoung HWANG ; Chang Moo KANG ; Woo Jung LEE ; Jung Hyun JO ; Taek CHUNG ; Sohyun HWANG ; Beodeul KANG ; Jung Sun KIM ; Chang-Il KWON ; Sangwoo KIM ; Hong Jae CHON ; Chang Gon KIM ; Young Nyun PARK ; Hye Jin CHOI
Clinical and Molecular Hepatology 2026;32(2):721-736
Background/Aims:
Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC.
Methods:
Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy.
Results:
With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC.
Conclusions
Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.
5.Germline Mutations Related to Complete Remission After Neoadjuvant Chemotherapy in Patients With Triple-negative Breast Cancer
Jee Hyun AHN ; Ji Soo PARK ; Dongju WON ; Seung-Tae LEE ; Suk Jun LEE ; Seung Hye YANG ; Jee Ye KIM ; Seho PARK ; Seung Il KIM ; Byeong-Woo PARK ; Min Hwan KIM ; Gun Min KIM ; Joohyuk SOHN ; Hyung Seok PARK
Journal of Breast Cancer 2026;29(2):118-127
Purpose:
Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing.
Methods:
A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs.
Results:
The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066).
Conclusion
Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.
6.Developing clinical skills assessment modules for traditional, complementary, and integrative medicine in Korea: a participatory action research study
Yoonjin JEONG ; Seung Hwan MUN ; Eunbyul CHO ; Hye-Yoon LEE ; Sang Woo SHIN ; Soyeon KIM ; Eui-hyoung HWANG ; Man-suk HWANG ; Eunseok KIM ; Jungyun LEE
Journal of Educational Evaluation for Health Professions 2026;23(1):10-
Purpose:
This study aimed to develop pilot clinical skills assessment (CSA) modules for Korean medicine-specific procedures and to examine their preliminary appropriateness, perceived necessity, and feasibility as a foundation for future licensing-related assessment development.
Methods:
A participatory action research framework, supplemented by qualitative interviews, was used to develop 4 CSA modules—acupuncture, Chuna manual therapy, pulse diagnosis, and constitutional diagnosis—in collaboration with expert evaluators, students, and standardized patients. The modules were implemented as formative examinations for third-year Korean medicine students, after which semi-structured interviews were conducted to obtain feedback on module content, implementation processes, and scoring procedures. Each module was also reviewed using the RUMBA checklist (Realistic, Understandable, Measurable, Behavioral, and Achievable), together with ratings of perceived necessity and feasibility for possible future use in licensing-related assessment. Interview data were analyzed inductively at the level of individual responses and then compared across modules and participant groups.
Results:
Qualitative analysis yielded 3 themes: content and scoring criteria, physical environment or simulators, and education or training. Participants emphasized the need to make key aspects of performance more observable, improve authenticity through simulators or task trainers, and strengthen the capacity of scoring systems to distinguish between levels of student performance. Across all modules, mean RUMBA scores were high in the understandable, behavioral, and achievable domains, whereas measurability was more problematic, especially for pulse diagnosis.
Conclusion
These pilot findings clarify both the strengths and the limitations of Korean medicine-specific CSA modules. The modules received favorable ratings for understandability and achievability, whereas lower ratings for measurability and realism identified priorities for refinement before wider use. This study provides preliminary guidance for the continued development and broader evaluation of Korean medicine-specific performance assessments.
7.Impact of Distal Fusion Level on Sacroiliac Joint Degenerative Change Following Adolescent Idiopathic Scoliosis Surgery
Sang-Ho KIM ; Jae-Won SHIN ; Seong-Hwan MOON ; Kyung-Soo SUK ; Si-Young PARK ; Byung-Ho LEE ; Ji-Won KWON ; Joong Won HA ; Yung PARK ; Hak-Sun KIM
Yonsei Medical Journal 2025;66(2):103-110
Purpose:
To evaluate the relationship between distal fusion level in correction and fusion surgery for adolescent idiopathic scoliosis (AIS) and radiologic changes in the sacroiliac (SI) joint.
Materials and Methods:
This retrospective cohort study evaluated patients who underwent correction and fusion for AIS between 2005 and 2017 with at least 5 years of follow-up. We categorized patients into two groups: Group 1 (distal fusion above L2, 74 patients) and Group 2 (distal fusion at L3 and below, 52 patients). Radiologic parameters and SI joint changes were evaluated on plain radiographs obtained from preoperative to 5 years postoperatively. We also investigated other risk factors for SI joint change.
Results:
Analysis of demographic factors revealed no significant difference between the two groups. There was a significant difference in the incidence of SI joint change between Group 1 (5 patients, 6.75%) and Group 2 (18 patients, 34.61%), with Group 2 showing a faster increase in incidence according to the Kaplan-Meier method (p<0.0001). Preoperative lumbar lordosis (LL) and ΔLL had a significant relationship with SI joint changes [preoperative LL, hazard ratio (HR)=0.77, 95% confidence interval (CI)=0.64– 0.93, p=0.008; ΔLL, HR=0.79, 95% CI=0.67–0.95, p=0.01).
Conclusion
After AIS surgery, patients who had fusion to the lower lumbar vertebrae (L3 or L4) experienced a higher incidence and faster progression of degenerative changes in the SI joint. Low preoperative LL and inadequate correction of LL during the operation were also risk factors for SI joint degeneration.
8.Laparoscopic and robotic surgery for colorectal cancer in Korea: a nationwide health insurance database analysis from 2019 to 2023
Eun Ji PARK ; Hyun Gu LEE ; Youn Young PARK ; Sun Jin PARK ; Kil Yeon LEE ; Suk-Hwan LEE
Journal of Minimally Invasive Surgery 2025;28(1):25-35
Purpose:
This study examined nationwide data regarding laparoscopic and robotic surgery for colorectal cancer (CRC) in Korea.
Methods:
Nationwide data concerning patients who underwent surgery for CRC from 2019 to 2023 were obtained from the Health Insurance Review and Assessment Service database.
Results:
From 2019 to 2023, a total of 109,573 patients with CRC underwent surgical resection in Korea. Among these, open, laparoscopic, and robotic surgery comprised 17.2%, 71.5%, and 11.3%, respectively. Open surgery decreased from 18.3% in 2019 to 15.2% in 2023, whereas robotic surgery increased from 10.3% in 2019 to 12.7% in 2023. Regarding rectal cancer, the rate of robotic surgery increased from 23.0% in 2019 to 28.2% in 2023, and the rate of minimally invasive surgery (MIS) increased from 86.9% in 2019 to 89.2% in 2023.Patients with National Health Insurance had significantly shorter lengths of hospital stay after surgery than those with medical aid for all surgical methods (p < 0.0001). With respect to hospital size, 74,282 CRC surgeries (67.8%) were performed in tertiary general hospitals and 33,050 (30.2%) in general hospitals. By the region, 47,140 cases (43.0%) were performed in Seoul, 19,961 (18.2%) in Gyeonggi, and 7,417 (6.8%) in Daegu. Ostomy was created in 16,222 CRC surgeries (14.8%).
Conclusion
The rate of MIS adoption for CRC in Korea has increased, reaching 84.7% in 2023. The rate of laparoscopic surgery exceeded 70% and has plateaued. In contrast, the rate of robotic surgery adoption has steadily increased, particularly for rectal cancer, where it surpassed 28% in 2023.
9.Characteristics and Prevalence of Sequelae after COVID-19: A Longitudinal Cohort Study
Se Ju LEE ; Yae Jee BAEK ; Su Hwan LEE ; Jung Ho KIM ; Jin Young AHN ; Jooyun KIM ; Ji Hoon JEON ; Hyeri SEOK ; Won Suk CHOI ; Dae Won PARK ; Yunsang CHOI ; Kyoung-Ho SONG ; Eu Suk KIM ; Hong Bin KIM ; Jae-Hoon KO ; Kyong Ran PECK ; Jae-Phil CHOI ; Jun Hyoung KIM ; Hee-Sung KIM ; Hye Won JEONG ; Jun Yong CHOI
Infection and Chemotherapy 2025;57(1):72-80
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.
10.Comparing Outcomes between Cage Alone and Plate Fixation in Single-Level Anterior Cervical Fusion: A Retrospective Clinical Series
Jae-Won SHIN ; Han-Bin JIN ; Yung PARK ; Joong-Won HA ; Hak-Sun KIM ; Kyung-Soo SUK ; Sung-Hwan MOON ; Si-Young PARK ; Byung-Ho LEE ; Ji-Won KWON ; In-Uk KIM
Clinics in Orthopedic Surgery 2025;17(3):417-426
Background:
To identify the optimal surgical technique for single-level anterior cervical discectomy and fusion (ACDF), this study compared surgical outcomes and incidence of adjacent segment degeneration (ASD) in patients undergoing single-level ACDF using cage alone single-level fusion and plate fixation techniques.
Methods:
This single-center retrospective study (2003–2018) included patients who underwent single-level ACDF with either plate fixation (PLATE) or cage (CAGE) alone. The radiologic and clinical outcomes between the 2 surgical groups were compared over a 4-year follow-up period. Outcomes of interest included parameters related to range of motion, sagittal alignment, as well as fusion, subsidence, and ASD rates. Clinical outcomes were evaluated using the Neck Disability Index (NDI) and visual analog scale (VAS) for pain. Dysphagia and hoarseness rates were estimated based on medical records.
Results:
Forty-seven patients were included (n=17 in CAGE group). In the CAGE group, 94.1% of the patients had Bridwell grade 1 or 2, compared to 83.3% in the PLATE group (p = 0.396). Subsidence occurred in 12.5% and 3.6% of the CAGE and PLATE cases, respectively (p = 0.543). Segmental kyphosis progressed in the CAGE group compared to the PLATE group at 12, 24, and 48 months (p < 0.001). Radiographic ASD was observed in 41.2% and 30.0% of patients in the CAGE and PLATE groups, respectively, with a higher incidence in the upper segments for both groups. Preoperative NDI scores were similar between the groups; however, postoperatively, the CAGE group had significantly lower NDI scores (3.50 ± 2.74 vs. 8.00 ± 5.81) at 4 years (p = 0.020). Neck pain VAS scores also showed significant improvement in the CAGE group (2.33 ± 2.94) compared with that in the PLATE group (3.07 ± 2.31) at 4 years (p = 0.045). Both groups showed comparable arm pain VAS scores at 2 and 4 years postoperatively. Postoperative dysphagia occurred in 1 patient in the PLATE group, resolving almost completely by 1 year.
Conclusions
Single-level ACDF using a cage alone technique demonstrated favorable radiologic and clinical outcomes overall compared to plate-augmented ACDF. However, plate augmentation is recommended for patients with severe cervical kyphosis or those at high risk of subsidence.

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