Background: This study aimed to investigate the densitometric characteristics and qualitative bone status in patients with normocalcemic primary hyperparathyroidism (PHPT) compared with those in controls who were younger adults under 50 years. Methods: This retrospective study included 60 controls and 31 patients with PHPT who underwent dual energy X-ray absorptiometry (DXA) of the lumbar spine (LS), femoral neck (FN), and total hip (TH). Trabecular bone score (TBS) was derived from LS DXA images. Bone mineral density (BMD) values were assessed using Z-scores, and correlations between TBS, BMD, and laboratory parameters were examined. Results: The median ages of the control and PHPT groups were 41 and 42 years, respectively. The proportion of individuals classified as “below the expected range for age” based on Z-scores differed significantly between groups only when considering any site collectively. Median TBS was significantly lower in PHPT patients than in controls, even when BMD values at LS, FN, and TH fell within similar diagnostic categories. In controls, TBS and BMD demonstrated very low correlation coefficients. In contrast, PHPT patients showed a stronger correlation between TBS and femoral BMD, whereas the association between TBS and LS BMD was largely absent. Among laboratory markers, only serum intact parathyroid hormone was significantly negatively correlated with TBS. Conclusions Young adults with PHPT exhibit impaired bone quality despite relatively preserved BMD, suggesting early microarchitectural deterioration. These findings support the combined use of LS and femoral BMD with TBS for more accurate assessment of skeletal health in PHPT.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area.Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version.Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

Background: Postsurgical hypocalcemia is the most common and troublesome consequence of thyroidectomy. We investigated the potential role of routine calcium or vitamin D supplementation in preventing postsurgical hypocalcemia. Methods: We searched MEDLINE and Embase for English-language publications using the keywords “calcium,” “vitamin D,” and “thyroid cancer.” The primary outcome was any postoperative hypocalcemia, and the secondary outcome was symptomatic hypocalcemia. Results: Four studies that included 381 patients were eligible for this meta-analysis. A random-effects model showed no significant difference in the occurrence of hypocalcemia between calcium/vitamin D treatment and placeboo treatment. However, the occurrence of symptomatic hypocalcemia was lower in patients with calcium/vitamin D treatment. In the combined results, preoperative calcium and vitamin D supplementation were associated with a reduced incidence of symptomatic hypocalcemia. Conclusions Our findings support the use of preoperative calcium and vitamin D supplementation in conjunction with routine postsurgical supplementation for patients after total thyroidectomy.

Background: Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized by various combinations of parkinsonism, cerebellar ataxia, autonomic dysfunction and pyramidal signs. Two clinical subtypes are recognized: MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P). The aim of this study was to compare pathological features between MSA-C and MSA-P. Methods: Two autopsy confirmed cases with MSA were included from the Pusan National University Hospital Brain Bank. Case 1 had been clinically diagnosed as MSA-C and case 2 as MSA-P. The severity of neuronal loss and gliosis as well as the glial and neuronal cytoplasmic inclusions were semiquantitatively assessed in both striatonigral and olivopontocerebellar regions. Based on the grading system, pathological phenotypes of MSA were classified as striatonigral degeneration (SND) predominant (SND type), olivopontocerebellar degeneration (OPC) predominant (OPC type), or equivalent SND and OPC pathology (SND=OPC type). Results: Both cases showed widespread and abundant α-synuclein positive glial cytoplasmic inclusions in association with neurodegenerative changes in striatonigral or olivopontocerebellar structures, leading to the primary pathological diagnosis of MSA. Primary age-related tauopathy was incidentally found but Lewy bodies were not in both cases. The pathological phenotypes of MSA were MSA-OPC type in case 1 and MSA-SND=OPC type in case 2. Conclusions Our data suggest that clinical phenotypes of MSA reflect the pathological characteristics.

Background: The aim of this study was to develop a scoring system to stratify the risk of papillary thyroid cancer (PTC) and to select the proper management. Methods: We performed a systematic search of MEDLINE and Embase. Data regarding patients’ prognoses were obtained from the included studies. Odds ratios (ORs) with statistical significance were extracted from the publications. To generate a risk scoring system (RSS), ORs were summed (RSS1), and summed after natural-logarithmic transformation (RSS2). RSS1 and RSS2 were compared to the eighth edition of the American Joint Committee on Cancer (AJCC) staging system and the 2015 American Thyroid Association (ATA) guidelines for thyroid nodules and differentiated thyroid carcinoma. Results: Five meta-analyses were eligible for inclusion in the study. Eight variables (sex, tumour size, extrathyroidal extension, BRAF mutation, TERT mutation, histologic subtype, lymph node metastasis, and distant metastasis) were included. RSS1 was the best of the analysed models. Conclusion We developed and validated a new RSS derived from previous meta-analyses for patients with PTC. This RSS seems to be superior to previously published systems.

We spend about one-third of our lives either sleeping or attempting to sleep. Therefore, the socioeconomic implications of sleepdisorders may be higher than expected. However, the fundamental mechanisms and functions of sleep are not yet fully understood.Neuroimaging has been utilized to reveal the connectivity between sleep and the brain, which is associated with thephysiology of sleep. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) imagingstudies have become increasingly common in sleep research. Recently, significant progress has been made in understanding thephysiology of sleep through neuroimaging and the use of various radiopharmaceuticals, as the sleep–wake cycle is regulated bymultiple neurotransmitters, including dopamine, adenosine, glutamate, and others. In addition, the characteristics of rapid eye andnon-rapid eye movement sleep have been investigated by measuring cerebral glucose metabolism. The physiology of sleep hasbeen investigated using PET to study glymphatic function as a means to clear the amyloid burden. However, the basic mechanismsand functions of sleep are not yet fully understood. Further studies are needed to investigate the effects and consequencesof chronic sleep deprivation, and the relevance of sleep to other diseases.

Purpose: This study aimed to construct a database of the effective doses (ED) from F-18 fluorodeoxyglucose (FDG) torso positron emission tomography/computed tomography (PET/CT) in Korea to provide data that supports the reduction of the CT dose of PET/CT and optimization of PET/CT protocols in Korea. Methods: We investigated data of ED and CT parameters of FDG PET/CT. The data were analyzed by body weight groups. Results: A total of 31 hospitals participated in the survey (99 adults). The mean total EDs (± SD) were 8.77 ± 2.76, 10.93 ± 3.14, and 12.57 ± 3.79 mSv for the 55-, 70-, and 85-kg groups, respectively. The FDG EDs were 4.80 ± 0.98, 6.05 ± 1.15, and 6.89 ± 1.52 mSv, and the CT EDs were 4.00 ± 2.12, 4.88 ± 2.51, and 5.68 ± 2.89 mSv, respectively. Of the enrolled hospitals, 54.5% used ultra-low-dose CT protocols, and their CT ED was significantly lower than low-dose CT group in all groups (2.9 ± 1.0, 3.2 ± 1.1, and 3.3 ± 1.0 mSv vs. 6.6 ± 1.6, 7.2 ± 2.1, and 7.9 ± 2.2 mSv, all p < 0.001, respectively). In the ultra-low-dose CT group, the CT ED with the iterative reconstruction was significantly lower than that of CT without iterative reconstruction in the 55-kg group (2.4 ± 0.9 vs. 3.3 ± 0.9, p = 0.04). Conclusions These results and current recommendations can be helpful for optimizing PET/CT diagnostic reference level (DRL) and reducing unnecessary PET/CT radiation exposure.