1.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
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.
2.Why large language models cannot possess consciousness: an integrated information theory perspective
Dong Ah SHIN ; Pyung Goo CHO ; Gyu Yeul JI ; Sang Hyuk PARK ; Soo Heon KIM ; Yoo Jin CHOO ; Min Cheol CHANG
Journal of Yeungnam Medical Science 2025;42(1):79-
Background:
The question of whether large language models (LLMs) possess consciousness has been increasingly debated. Integrated information theory (IIT) offers a quantitative framework for assessing consciousness through a measure of integrated information.
Methods:
This study applied IIT principles to the architecture of transformer-based LLMs, focusing on causal integration, temporal persistence, and system irreducibility. Ablation experiments on Generative Pretrained Transformer 2 (GPT-2) were performed, selectively removing individual attention heads and measuring changes in perplexity as a behavioral proxy for integrated information to empirically approximate the measure of integrated information.
Results:
The ablation study of a single attention head produced minimal or negative changes in perplexity in four out of five representative sentences, indicating redundancy or noise. Only one sentence revealed a significant increase in perplexity change (ΔPPL +11.29), reflecting a localized but nonessential contribution. A comparison with biological systems demonstrated that LLMs meet the IIT criterion of differentiation, but fail to meet the criteria of integration, causal closure, and temporal persistence. These findings confirm that LLMs are architecturally decomposable, lack persistent internal states, and do not sustain global causal irreducibility. Philosophical considerations, including Searle’s Chinese Room argument, further support the idea that the linguistic fluency of LLMs arises from syntactic manipulation rather than semantic understanding.
Conclusion
Current LLMs do not satisfy the structural and informational requirements of consciousness under IIT. Although capable of simulating intelligent language, LLMs remain unconscious systems with a negligible amount of integrated information, underscoring the distinction between linguistic competence and conscious experience.
3.2025 Korean Thyroid Association Clinical Management Guideline on Active Surveillance for Low-Risk Papillary Thyroid Carcinoma
Eun Kyung LEE ; Min Joo KIM ; Seung Heon KANG ; Bon Seok KOO ; Kyungsik KIM ; Mijin KIM ; Bo Hyun KIM ; Ji-hoon KIM ; Shin Je MOON ; Kyorim BACK ; Young Shin SONG ; Jong-hyuk AHN ; Hwa Young AHN ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Jeongmin LEE ; Ji Ye LEE ; Kyong Yeun JUNG ; Chan Kwon JUNG ; Yoon Young CHO ; Dong-Jun LIM ; Sun Wook KIM ; Young Joo PARK ; Dong Gyu NA ; Jee Soo KIM
International Journal of Thyroidology 2025;18(1):30-64
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.
4.Institution-Specific Autosegmentation for Personalized Radiotherapy Protocols
Wonyoung CHO ; Gyu Sang YOO ; Won Dong KIM ; Yerim KIM ; Jin Sung KIM ; Byung Jun MIN
Progress in Medical Physics 2024;35(4):205-213
Purpose:
This study explores the potential of artificial intelligence (AI) in optimizing radiotherapy protocols for personalized cancer treatment. Specifically, it investigates the role of AI-based segmentation tools in improving accuracy and efficiency across various anatomical regions.
Methods:
A dataset of 500 anonymized patient computed tomography scans from Chungbuk National University Hospital was used to develop and validate AI models for segmenting organs-atrisk. The models were tailored for five anatomical regions: head and neck, chest, abdomen, breast, and pelvis. Performance was evaluated using Dice Similarity Coefficient (DSC), Mean Surface Distance, and the 95th Percentile Hausdorff Distance (HD95).
Results:
The AI models achieved high segmentation accuracy for large, well-defined structures such as the brain, lungs, and liver, with DSC values exceeding 0.95 in many cases. However, challenges were observed for smaller or complex structures, including the optic chiasm and rectum, with instances of segmentation failure and infinity values for HD95. These findings highlight the variability in performance depending on anatomical complexity and structure size.
Conclusions
AI-based segmentation tools demonstrate significant potential to streamline radiotherapy workflows, reduce inter-observer variability, and enhance treatment accuracy. Despite challenges with smaller structures, the integration of AI enables dynamic, patient-specific adaptations to anatomical changes, contributing to more precise and effective cancer treatments.Future work should focus on refining models for anatomically complex structures and validating these methods in diverse clinical settings.
5.Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 4: Liver and locally recurrent rectal cancer
Hwa Kyung BYUN ; Gyu Sang YOO ; Soo-Yoon SUNG ; Jin-Ho SONG ; Byoung Hyuck KIM ; Yoo-Kang KWAK ; Yeon Joo KIM ; Yeon-Sil KIM ; Kyung Su KIM
Radiation Oncology Journal 2024;42(4):247-256
In this paper, we review the use of hypofractionated radiotherapy for gastrointestinal malignancies, focusing on primary and metastatic liver cancer, and recurrent rectal cancer. Technological advancements in radiotherapy have facilitated the direct delivery of high-dose radiation to tumors, while limiting normal tissue exposure, supporting the use of hypofractionation. Hypofractionated radiotherapy is particularly effective for primary and metastatic liver cancer where high-dose irradiation is crucial to achieve effective local control. For recurrent rectal cancer, the use of stereotactic body radiotherapy offers a promising approach for re-irradiation, balancing efficacy and safety in patients who have been administered previous pelvic radiotherapy and in whom salvage surgery is not applicable. Nevertheless, the potential for radiation-induced liver disease and gastrointestinal complications presents challenges when applying hypofractionation to gastrointestinal organs. Given the lack of universal consensus on hypofractionation regimens and the dose constraints for primary and metastatic liver cancer, as well as for recurrent rectal cancer, this review aims to facilitate clinical decision-making by pointing to potential regimens and dose constraints, underpinned by a comprehensive review of existing clinical studies and guidelines.
6.Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 3. Genitourinary and gynecological cancers
Gyu Sang YOO ; Soo-Yoon SUNG ; Jin Ho SONG ; Byoung Hyuck KIM ; Yoo-Kang KWAK ; Kyung Su KIM ; Hwa Kyung BYUN ; Yeon-Sil KIM ; Yeon Joo KIM
Radiation Oncology Journal 2024;42(3):171-180
Hypofractionated radiotherapy (RT) has become a trend in the modern era, as advances in RT techniques, including intensity-modulated RT and image-guided RT, enable the precise and safe delivery of high-dose radiation. Hypofractionated RT offers convenience and can reduce the financial burden on patients by decreasing the number of fractions. Furthermore, hypofractionated RT is potentially more beneficial for tumors with a low α/β ratio compared with conventional fractionation RT. Therefore, hypofractionated RT has been investigated for various primary cancers and has gained status as a standard treatment recommended in the guidelines. In genitourinary (GU) cancer, especially prostate cancer, the efficacy, and safety of various hypofractionated dose schemes have been evaluated in numerous prospective clinical studies, establishing the standard hypofractionated RT regimen. Hypofractionated RT has also been explored for gynecological (GY) cancer, yielding relevant evidence in recent years. In this review, we aimed to summarize the representative evidence and current trends in clinical studies on hypofractionated RT for GU and GY cancers addressing several key questions. In addition, the objective is to offer suggestions for the available dose regimens for hypofractionated RT by reviewing protocols from previous clinical studies.
7.Practice guidelines for managing extrahepatic biliary tract cancers
Hyung Sun KIM ; Mee Joo KANG ; Jingu KANG ; Kyubo KIM ; Bohyun KIM ; Seong-Hun KIM ; Soo Jin KIM ; Yong-Il KIM ; Joo Young KIM ; Jin Sil KIM ; Haeryoung KIM ; Hyo Jung KIM ; Ji Hae NAHM ; Won Suk PARK ; Eunkyu PARK ; Joo Kyung PARK ; Jin Myung PARK ; Byeong Jun SONG ; Yong Chan SHIN ; Keun Soo AHN ; Sang Myung WOO ; Jeong Il YU ; Changhoon YOO ; Kyoungbun LEE ; Dong Ho LEE ; Myung Ah LEE ; Seung Eun LEE ; Ik Jae LEE ; Huisong LEE ; Jung Ho IM ; Kee-Taek JANG ; Hye Young JANG ; Sun-Young JUN ; Hong Jae CHON ; Min Kyu JUNG ; Yong Eun CHUNG ; Jae Uk CHONG ; Eunae CHO ; Eui Kyu CHIE ; Sae Byeol CHOI ; Seo-Yeon CHOI ; Seong Ji CHOI ; Joon Young CHOI ; Hye-Jeong CHOI ; Seung-Mo HONG ; Ji Hyung HONG ; Tae Ho HONG ; Shin Hye HWANG ; In Gyu HWANG ; Joon Seong PARK
Annals of Hepato-Biliary-Pancreatic Surgery 2024;28(2):161-202
Background:
s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021.
Methods:
Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop.
Results:
In November 2021, the finalized draft was presented for public scrutiny during a formal hearing.
Conclusions
The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.
8.The Clinical Efficacy of Colorectal Cancer Patients with Pulmonary Oligometastases by Sterotactic Body Ablative Radiotherapy: A Meta-Analysis
Jae-Uk JEONG ; Chai Hong RIM ; Gyu Sang YOO ; Won Kyung CHO ; Eui Kyu CHIE ; Yong Chan AHN ; Jong Hoon LEE ;
Cancer Research and Treatment 2024;56(3):809-824
Purpose:
There is increasing interest in the efficacy of stereotactic ablative radiotherapy (SABR) for treating colorectal cancer (CRC) patients with oligometastases (OM), recently. The purpose of this meta-analysis was to evaluate local control (LC), progression-free survival (PFS), and overall survival (OS) of CRC patients with pulmonary OM treated with SABR and toxicities.
Materials and Methods:
Studies that reported SABR for CRC patients with pulmonary OM were searched from MEDLINE and Embase. Treatment outcomes including LC, PFS, OS, and toxicities of grade 3 or higher were assessed.
Results:
A total of 19 studies with 1,668 patients were chosen for this meta-analysis. Pooled 1-, 2-, and 3-year LC rates were 83.1%, 69.3%, and 63.9%, respectively. PFS rates were 44.8%, 26.5%, and 21.5% at 1, 2, and 3 years, respectively. OS rates at 1-, 2-, and 3-year were 87.5%, 69.9%, and 60.5%, respectively. The toxicity rate of grade 3 or higher was 3.6%. The effect of dose escalation was meta-analyzed using available studies.
Conclusion
Application of SABR to CRC patients with pulmonary OM achieved modest local control with acceptable toxicity according to the present meta-analysis. Further studies establishing the clinical efficacy of SABR are guaranteed.
9.Study Design and Protocol for a Randomized Controlled Trial to Assess Long-Term Efficacy and Safety of a Triple Combination of Ezetimibe, Fenofibrate, and Moderate-Intensity Statin in Patients with Type 2 Diabetes and Modifiable Cardiovascular Risk Factors (ENSEMBLE)
Nam Hoon KIM ; Juneyoung LEE ; Suk CHON ; Jae Myung YU ; In-Kyung JEONG ; Soo LIM ; Won Jun KIM ; Keeho SONG ; Ho Chan CHO ; Hea Min YU ; Kyoung-Ah KIM ; Sang Soo KIM ; Soon Hee LEE ; Chong Hwa KIM ; Soo Heon KWAK ; Yong‐ho LEE ; Choon Hee CHUNG ; Sihoon LEE ; Heung Yong JIN ; Jae Hyuk LEE ; Gwanpyo KOH ; Sang-Yong KIM ; Jaetaek KIM ; Ju Hee LEE ; Tae Nyun KIM ; Hyun Jeong JEON ; Ji Hyun LEE ; Jae-Han JEON ; Hye Jin YOO ; Hee Kyung KIM ; Hyeong-Kyu PARK ; Il Seong NAM-GOONG ; Seongbin HONG ; Chul Woo AHN ; Ji Hee YU ; Jong Heon PARK ; Keun-Gyu PARK ; Chan Ho PARK ; Kyong Hye JOUNG ; Ohk-Hyun RYU ; Keun Yong PARK ; Eun-Gyoung HONG ; Bong-Soo CHA ; Kyu Chang WON ; Yoon-Sok CHUNG ; Sin Gon KIM
Endocrinology and Metabolism 2024;39(5):722-731
Background:
Atherogenic dyslipidemia, which is frequently associated with type 2 diabetes (T2D) and insulin resistance, contributes to the development of vascular complications. Statin therapy is the primary approach to dyslipidemia management in T2D, however, the role of non-statin therapy remains unclear. Ezetimibe reduces cholesterol burden by inhibiting intestinal cholesterol absorption. Fibrates lower triglyceride levels and increase high-density lipoprotein cholesterol (HDL-C) levels via peroxisome proliferator- activated receptor alpha agonism. Therefore, when combined, these drugs effectively lower non-HDL-C levels. Despite this, few clinical trials have specifically targeted non-HDL-C, and the efficacy of triple combination therapies, including statins, ezetimibe, and fibrates, has yet to be determined.
Methods:
This is a multicenter, prospective, randomized, open-label, active-comparator controlled trial involving 3,958 eligible participants with T2D, cardiovascular risk factors, and elevated non-HDL-C (≥100 mg/dL). Participants, already on moderate-intensity statins, will be randomly assigned to either Ezefeno (ezetimibe/fenofibrate) addition or statin dose-escalation. The primary end point is the development of a composite of major adverse cardiovascular and diabetic microvascular events over 48 months.
Conclusion
This trial aims to assess whether combining statins, ezetimibe, and fenofibrate is as effective as, or possibly superior to, statin monotherapy intensification in lowering cardiovascular and microvascular disease risk for patients with T2D. This could propose a novel therapeutic approach for managing dyslipidemia in T2D.
10.Evaluation of the Efficacy and Safety of DW1903 in Patients with Gastritis: A Randomized, Double-Blind, Noninferiority, Multicenter, Phase 3 study
Jie-Hyun KIM ; Hwoon-Yong JUNG ; In Kyung YOO ; Seon-Young PARK ; Jae Gyu KIM ; Jae Kyu SUNG ; Jin Seok JANG ; Gab Jin CHEON ; Kyoung Oh KIM ; Tae Oh KIM ; Soo Teik LEE ; Kwang Bum CHO ; Hoon Jai CHUN ; Jong-Jae PARK ; Moo In PARK ; Jae-Young JANG ; Seong Woo JEON ; Jin Woong CHO ; Dae Hwan KANG ; Gwang Ha KIM ; Jae J. KIM ; Sang Gyun KIM ; Nayoung KIM ; Yong Chan LEE ; Su Jin HONG ; Hyun-Soo KIM ; Sora LEE ; Sang Woo LEE
Gut and Liver 2024;18(1):70-76
Background/Aims:
H2 receptor antagonists (H2RA) have been used to treat gastritis by inhibiting gastric acid. Proton pump inhibitors (PPIs) are more potent acid suppressants than H2RA.However, the efficacy and safety of low-dose PPI for treating gastritis remain unclear. The aim was to investigate the efficacy and safety of low-dose PPI for treating gastritis.
Methods:
A double-blind, noninferiority, multicenter, phase 3 clinical trial randomly assigned 476 patients with endoscopic erosive gastritis to a group using esomeprazole 10 mg (DW1903) daily and a group using famotidine 20 mg (DW1903R1) daily for 2 weeks. The full-analysis set included 319 patients (DW1903, n=159; DW1903R1, n=160) and the per-protocol set included 298 patients (DW1903, n=147; DW1903R1, n=151). The primary endpoint (erosion improvement rate) and secondary endpoint (erosion and edema cure rates, improvement rates of hemorrhage, erythema, and symptoms) were assessed after the treatment. Adverse events were compared.
Results:
According to the full-analysis set, the erosion improvement rates in the DW1903 and DW1903R1 groups were 59.8% and 58.8%, respectively. According to the per-protocol analysis, the erosion improvement rates in the DW1903 and DW1903R1 groups were 61.9% and 59.6%, respectively. Secondary endpoints were not significantly different between two groups except that the hemorrhagic improvement rate was higher in DW1903 with statistical tendency. The number of adverse events were not statistically different.
Conclusions
DW1903 of a low-dose PPI was not inferior to DW1903R1 of H2RA. Thus, lowdose PPI can be a novel option for treating gastritis (ClinicalTrials.gov Identifier: NCT05163756).

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