Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder affecting the sacroiliac joints and axial spine. Along with pharmacotherapy, non-pharmacological interventions for axSpA are crucial and constitute the cornerstone of treatment. Here, we review the evidence for non-pharmacological treatment of axSpA as a basis for the 2023 Korean treatment recommendations for patients with axSpA. The effectiveness of the core non-pharmacological approaches, such as education, smoking cessation, and exercise, has been reaffirmed. High-quality research on surgical treatment is limited. However, total hip replacement is advised in patients with ongoing pain or disability and visible structural damage to the hip on imaging. Urgent spinal intervention should be considered in cases of acute spinal pain with neurological deficiency or concurrent unstable fractures. Evidence for complementary therapies, including spas and acupuncture, remains insufficient.

Background: Primary Merkel cell carcinoma of the salivary gland is currently not listed in the World Health Organization classification. However, cases of Merkel cell type neuroendocrine carcinomas of the salivary gland with perinuclear cytokeratin 20 positivity have been intermittently reported. We here investigated the clinicopathologic features of additional cases. Methods: Data of four cases of Merkel cell type small cell neuroendocrine carcinoma of the salivary gland were retrieved. To confirm the tumors’ primary nature, clinical records and pathologic materials were reviewed. Optimal immunohistochemical staining was performed to support the diagnosis. Results: All tumors were located in the parotid gland. Possibilities of metastasis were excluded in all cases through a meticulous clinicopathological review. Tumor histology was consistent with the diagnosis of small cell neuroendocrine carcinoma. Tumors’ immunohistochemical phenotypes were consistent with Merkel cell carcinoma, including Merkel cell polyomavirus large T antigen positivity in two of the four cases. Conclusions Merkel cell carcinomas can originate in salivary glands and are partly associated with Merkel cell polyomavirus infection as in cutaneous Merkel cell carcinomas.

Background: Complete revascularization has demonstrated better outcomes in patients with acute myocardial infarction (AMI) and multivessel disease. However, in the case of left main (LM) culprit lesion AMI with multivessel disease, there is limited evidence to suggest that complete revascularization is better. Methods: We reviewed 16,831 patients in the Korea Acute Myocardial Infarction Registry who were treated from July 2016 to June 2020, and 399 patients were enrolled with LM culprit lesion AMI treated with percutaneous coronary intervention. We categorized the patients as those treated with complete revascularization (n=295) or incomplete revascularization (n=104). The study endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, myocardial infarction, ischemia-driven revascularization, stent thrombosis, and stroke. We performed propensity score matching (PSM) and analyzed the incidence of MACCE at 1 year. Results: After PSM, the two groups were well balanced. There was no significant difference between the two groups in MACCE at 1 year (12.1% vs. 15.2%; hazard ratio, 1.28; 95% confidence interval, 0.60–2.74; p=0.524) after PSM. The components of MACCE and major bleeding were also not significantly different. Conclusion There was no significant difference in clinical outcomes between the groups treated with complete or incomplete revascularization for LM culprit lesion AMI with multivessel disease.

Purpose: Patients with stage I colorectal cancer (CRC) rarely experience recurrence after curative resection. Therefore, the risk factors for stage I CRC recurrence are yet to be established. We aimed to identify risk factors for stage I CRC recurrence. Methods: MEDLINE, Embase, and Cochrane Library were searched for articles published between 1990 and 2022. The pooled proportions and hazard ratios (HRs) were calculated. Fixed- or random-effect models were considered based on heterogeneity, using Cochran’s Q-statistic and the I2 -test. Results: Nine studies involving 19,440 patients were included. Nine analyzed risk factors were identified. T2 stage (pooled HR, 2.070; 95% confidence interval [CI], 1.758–2.438; P < 0.001; I2 =0.0%), lymphovascular invasion (HR, 1.685; 95% CI, 1.420–1.999; P < 0.001; I2 = 0.0%), venous invasion (HR, 1.794; 95% CI, 1.515–2.125; P < 0.001; I2 = 0.0%), CEA level (HR, 1.472; 95% CI, 1.093–1.983; P = 0.011; I2 = 1.8%) and rectal cancer (HR, 2.981; 95% CI, 2.378–3.735; P < 0.001; I2 = 0.0%) were risk factors for the recurrence. However, the risk of recurrence in right-sided colon cancer was lower than in leftsided colon cancer. (HR, 0.712; 95% CI, 0.537–0.944; P = 0.018; I2 = 0.0%). No statistically significant differences were observed in the number of harvested lymph nodes, age, and sex. Conclusion T2 stage, lymphovascular invasion, venous invasion, CEA level, rectal cancer, and left-sided colon cancer were risk factors for recurrence in stage I CRC. Intensive monitoring and surveillance are warranted for patients with high-risk features of recurrence.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules, recurrent thyroid cancers (RTCs), and primary thyroid microcarcinomas. The Korean Society of Thyroid Radiology (KSThR) initially developed recommendations for the optimal use of RFA for thyroid tumors in 2009 and revised them in 2012 and 2017. As new meaningful evidence has accumulated since 2017 and in response to a growing global interest in the use of RFA for treating malignant thyroid lesions, the task force committee members of the KSThR decided to update the guidelines on the use of RFA for the management of RTCs based on a comprehensive analysis of current literature and expert consensus.

PURPOSE: The aim of this study was to evaluate the clinical performance and survival rate of implant-supported zirconia-lithium disilicate (Zr-LiSi) bilayered ceramic prostheses over 3 years. MATERIALS AND METHODS: This study included 71 patients, including 34 with implant-supported metal-ceramic prostheses (control group) and 37 with implant-supported Zr-LiSi bilayered ceramic prostheses (test group). The implant survival rate and incidence of prosthetic and biological complications (veneer fractures, dislodgement of screw-access hole filling material, screw loosening, peri-implant mucositis and peri-implantitis, and marginal bone loss) were investigated. The survival rate was analyzed using Kaplan-Meier survival curves, and the identity between two groups was confirmed by the log-rank test. RESULTS: Both groups showed a 100% survival rate, whereas the prosthetic survival rates were 77% and 73% for the metal-ceramic and Zr-LiSi groups, respectively. Biological complications did not appear in the metal-ceramic group, and 16.2% of peri-implant mucositis occurred in the Zr-LiSi group, which was significant (P < .05). Prosthetic complications occurred in 5.8% of the metal-ceramic group with veneer fractures and did not occur in the Zr-LiSi bilayered ceramic group. CONCLUSION This study revealed that posterior Zr-LiSi bilayered ceramic implant prostheses showed high survival rates and similar survival rates to metal-ceramic implant prostheses; however, additional consideration should be given to avoid overcontouring. Zr-LiSi bilayered ceramic implant prostheses may be an option for posterior implant-supported prosthetic treatment.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder affecting the sacroiliac joints and axial spine. Along with pharmacotherapy, non-pharmacological interventions for axSpA are crucial and constitute the cornerstone of treatment. Here, we review the evidence for non-pharmacological treatment of axSpA as a basis for the 2023 Korean treatment recommendations for patients with axSpA. The effectiveness of the core non-pharmacological approaches, such as education, smoking cessation, and exercise, has been reaffirmed. High-quality research on surgical treatment is limited. However, total hip replacement is advised in patients with ongoing pain or disability and visible structural damage to the hip on imaging. Urgent spinal intervention should be considered in cases of acute spinal pain with neurological deficiency or concurrent unstable fractures. Evidence for complementary therapies, including spas and acupuncture, remains insufficient.