In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Spinocerebellar ataxia type 3 (SCA3) is an autosomal-dominant neurodegenerative disorder caused by an expanded polyglutamine repeat in the ataxin-3 gene. The resulting mutant ataxin-3 protein forms intraneuronal inclusions that lead to neurodegeneration in the cerebellum and other brain regions. This study aimed to develop a novel nonhuman primate model of SCA3 to address the limitations of existing knock-in and transgenic models using an adeno-associated virus (AAV) to deliver the mutant gene. AAV viral vectors carrying mutant ataxin-3 were stereotaxically injected into the cerebellum of monkeys. The animals were monitored over an 8-week period, during which behavioral and neuroimaging assessments were conducted. This was followed by a detailed pathological examination. The AAV vector successfully spread throughout the cerebellum, and the expression of mutant ataxin-3 was confirmed. Neuroimaging revealed a reduction in N-acetylaspartate (NAA) levels, whereas histological analysis showed significant damage to the Purkinje cell layer. Notably, the monkeys exhibited sleep disturbances, a prodromal symptom commonly observed in human patients with SCA3. AAV-mediated delivery of mutant ataxin-3 can effectively replicate the key pathological and clinical features of SCA3 in primates. This approach offers a promising new model for studying disease mechanisms and evaluating potential therapies.

The increasing detection of papillary thyroid microcarcinoma (PTMC) has raised concerns about overtreatment.For low-risk PTMC, either immediate surgery or active surveillance (AS) can be considered. To support AS implementation, the Korean Thyroid Association convened a multidisciplinary panel and developed the first Korean guideline. AS is recommended to adults with pathologically proven Bethesda V-VI PTMC without clinical evidence of lymph node or distant metastasis, gross extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, or aggressive histology. Baseline assessment requires high‑resolution cervical ultrasound by experienced operators to rule out extrathyroidal extension, tracheal or recurrent laryngeal nerve invasion, and lymph node metastasis;contrast‑enhanced neck computed tomography is optional. Patient characteristics such as age, comorbidities, and capacity for long-term follow-up should be assessed. Shared decision-making should weigh the benefits and risks of surgery and AS, expected oncologic outcomes, complications, quality of life, anxiety, medical cost, and patient preference. Follow-up includes cervical ultrasound and thyroid function test every six months for two years, then annually. Disease progression, defined as significant tumor growth or newly detected nodal or distant metastasis, warrants surgery. Despite remaining uncertainties, this guideline offers a framework to ensure oncologic safety and support patient-centered active surveillance.

The surgical reconstruction of the anterior cruciate ligament (ACL) has shown continuous advances, but concerns persist regarding its instability, the occurrence of post-traumatic osteoarthritis, and the high frequency of re-ruptures. Despite the lack of consensus regarding the precise structure of the anterolateral ligament (ALL) complex, this structure is anatomically present, and it can be damaged concurrently with the ACL, providing resistance to rotational instability. The debate regarding the timing and necessity of additional surgeries during ACL reconstruction is ongoing. Some authors advocate for concurrent procedures because of various risk factors, despite the widely varying opinions on this issue. Common adjunctive surgical techniques include ALL reconstruction and lateral extra-articular tenodesis. These procedures typically use various grafts and generally produce favorable clinical outcomes. Nevertheless, additional surgeries should be considered in certain cases because standard ACL reconstruction techniques may not be suitable for all patients. These cases include revision reconstructions, patients under 20 years old with high activity levels, those experiencing significant rotational instability, and individuals with specific anatomical risk factors. In such cases, procedures targeting the ALL complex may offer added benefits.

Background and Objectives: The leakage of cerebrospinal fluid due to damage to the ethmoid roof and cribriform plate (CP) is one of the most serious complications of endoscopic sinus surgery (ESS). For the risk of skull base injury during ESS, the Keros classification has been widely used, but recently the Gera classification has been introduced as a tool for risk assessment. This study evaluated the risk of skull base damage using the Gera classification in Koreans.Subjects and Method We analyzed 592 left and right sides of 296 paranasal sinus CTs, and measure the angle between the lateral lamella of CP and the lateral extension of the horizontal plane passing through CP, namely the Gera angle. The angles were classified into three categories: the type I (>80°, low risk), type II (45° to 80°, medium risk), and type III (<45°, high risk). Results: The type III, which is vulnerable to skull base damage, accounted for 11.7% of the study subjects. The Gera angle in females (64.0°±12.3°) was greater than that in males (61.3°± 14.0°), showing a significant gender difference (p=0.015). Although there was no difference between the left and the right side of the Gera angle (p=0.155), there was a significant difference between the left and the right side in the Gera classification (p<0.001). Age and the Gera angle showed a negative correlation (r=-0.116, p=0.005). Conclusion The type III of the Gera classification was observed in 11.7% of the total study group. For the type III, extra care is required during ESS.

Background and Objectives: The maxillary sinus disease is mainly treated through the middle meatal antrostomy, but there is a disadvantage in that it does not approach the lesions of the anterior wall of the maxillary sinus. On the other hand, the prelacrimal recess approach (PLA) can be used to access the lesions of the anterior wall of the maxillary sinus. However, complications after PLA may include nasal bleeding, infection, epiphora, and neurological symptoms. We investigated the possibility of neurological morbidity (anterior superior alveolar nerve injury) after PLA by imaging.Subjects and Method A total of 253 people were studied by using 506 samples of paranasal sinus CT. According to the Simmen and Arosio methods, the study groups were classified into the following categories: PLA type I (<3 mm), type II (3-7 mm), and type III (>7 mm), internal angle of pyriform notch (IAPN), type A (below 45°), type B (from 45° to 60°), and type C (60° excessive). Results: Of the PLA types, the IAPN value was the largest in the type III and smallest in the type I, and there were significant differences among the three groups (p<0.001). Conclusion CT Evaluation prior to PLA would help physicians to predict the likelihood of neurological morbidity such as maxillary sensory abnormalities.

Non-human primates, due to their high genetic similarity to humans, are used as laboratory animals in biotechnology researches. The growing demand has recently led to a shortage of primate resources, which has become a significant issue both domestically and internation-ally. This shortage has been further exacerbated by the COVID-19 pandemic. Consequently, the importance of resource conservation through effective primate management is increas-ing. This requires the establishment of proper quarantine procedures and infectious disease control. Quarantine is an important process that protects not only animal health but also pub-lic health significance. Non-human primate quarantine procedures were organized in order.We compared the differences in quarantine procedures not only in Korea but also in variouscountries such as the US, EU, and Australia. In addition, the etiology, clinical symptoms, diagnosis, and treatment methods of representative infectious diseases of quarantine concern(tuberculosis, monkeypox, monkey immunodeficiency virus, salmonellosis, and shigellosis) were summarized. A literature review of nonhuman primate quarantine procedures in other countries revealed minimal differences in the basic structure. The quarantine periods were similar around 30 days, but we found some differences in details such as legal requirements, documentation forms, and quarantine authorities. These findings are expected to contributeto the development of strategies for improving methods to prevent the spread of infectious diseases and enhancing quarantine management methods.

Non-human primates, due to their high genetic similarity to humans, are used as laboratory animals in biotechnology researches. The growing demand has recently led to a shortage of primate resources, which has become a significant issue both domestically and internation-ally. This shortage has been further exacerbated by the COVID-19 pandemic. Consequently, the importance of resource conservation through effective primate management is increas-ing. This requires the establishment of proper quarantine procedures and infectious disease control. Quarantine is an important process that protects not only animal health but also pub-lic health significance. Non-human primate quarantine procedures were organized in order.We compared the differences in quarantine procedures not only in Korea but also in variouscountries such as the US, EU, and Australia. In addition, the etiology, clinical symptoms, diagnosis, and treatment methods of representative infectious diseases of quarantine concern(tuberculosis, monkeypox, monkey immunodeficiency virus, salmonellosis, and shigellosis) were summarized. A literature review of nonhuman primate quarantine procedures in other countries revealed minimal differences in the basic structure. The quarantine periods were similar around 30 days, but we found some differences in details such as legal requirements, documentation forms, and quarantine authorities. These findings are expected to contributeto the development of strategies for improving methods to prevent the spread of infectious diseases and enhancing quarantine management methods.

Thyroid nodules represent a prevalent condition that is detectable via palpation or ultrasound. In recent years, there has been a paradigm shift toward enhanced diagnostic precision and less aggressive therapeutic approaches, highlighting the growing necessity for tailored clinical recommendations to optimize patient outcomes. The Korean Thyroid Association (KTA) has developed guidelines for managing patients with thyroid nodules, following a comprehensive review by task force members of the relevant literature identified via electronic database searches. The recommendations are provided with a level of recommendation for each section. The guidelines encompass thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, role of pathologic and molecular marker testing in making a diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major revisions that were made in the 2023 guidelines were the definition of high-risk groups for thyroid cancer screening, application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), addition of the role of core needle biopsy and molecular marker tests, application of active surveillance in patients with low-risk papillary thyroid microcarcinoma, and updated indications for nonsurgical treatment of benign thyroid nodules. In the 2024 revision of the KTA guidelines for thyroid cancer, the evidence for some recommendations has been updated to address the tumor size in the context of active surveillance in patients with low-risk thyroid cancer and the surgical size cutoff. These evidence-based recommendations serve to inform clinical decision-making in the management of thyroid nodules, thereby facilitating the delivery of optimal and efficacious treatments to patients.

Pediatric differentiated thyroid cancers (DTCs), mostly papillary thyroid cancer (PTC, 80-90%), are diagnosed at more advanced stages with larger tumor sizes and higher rates of locoregional and/or lung metastasis. Despite the higher recurrence rates of pediatric cancers than of adult thyroid cancers, pediatric patients demonstrate a lower mortality rate and more favorable prognosis. Considering the more advanced stage at diagnosis in pediatric patients, preoperative evaluation is crucial to determine the extent of surgery required. Furthermore, if hereditary tumor syndrome is suspected, genetic testing is required. Recommendations for pediatric DTCs focus on the surgical principles, radioiodine therapy according to the postoperative risk level, treatment and follow-up of recurrent or persistent diseases, and treatment of patients with radioiodine-refractory PTCs on the basis of genetic drivers that are unique to pediatric patients.