The American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging classification of thyroid cancer can predict death but cannot determine the type and frequency of follow-up testing. Risk stratification is a concept proposed by the American Thyroid Association that uses additional prognostic factors that are not included in the AJCC/UICC classification, such as number or size of metastatic lymph nodes, genetic mutations, and vascular invasion in follicular cancer, to further refine the prognosis of thyroid cancer. The risk of recurrence was categorized as low, intermediate, and high risk, and the need for total thyroidectomy, radioiodine therapy, or thyroid-stimulating hormone suppression was determined depending on each risk level. This approach has been accepted worldwide, and the previous recommendations of the Korean Thyroid Association followed a similar line of thinking but these have been modified in the revised 2024 guidelines.For the revised initial risk stratification, after careful review of the results of the recent meta-analyses and large observational studies and after a multidisciplinary meeting, four major changes were made: 1) thyroid cancer was reclassified according to the World Health Organization (WHO) 2022 tumor classification system; 2) recurrence risk was stratified by combining encapsulated follicular variant papillary thyroid cancer, follicular thyroid cancer, and oncocytic thyroid cancer, which have similar recurrence risk and associated factors, into follicular-patterned tumor; 3) low-risk groups were defined as those with a known recurrence rate of ≤5%, high-risk groups were upgraded to those with a known recurrence rate of ≥30%, and intermediate-risk groups were those with a recurrence risk of 5–30%; and 4) the intermediate risk group had the recurrence rate presented according to various clinicopathological factors, mainly based on reports from Korea. Thus, it is recommended to evaluate the initial risk group by predicting the recurrence rate by combining each clinical factor in individual patients, rather than applying the recurrence rate caused by single risk factor.

Only a small percentage of patients (2-5%) with differentiated thyroid cancer (DTC) exhibit distant metastasis at the initial diagnosis or during the disease course. The most common metastatic sites of DTC are the lungs, followed by the bones. Radioactive iodine (RAI) therapy is considered the primary treatment for RAI-avid distant metastatic DTC. Depending on the characteristics of metastatic lesions, local treatment such as surgical resection, radiofrequency ablation, and external beam radiation therapy may be considered for some patients with metastatic DTC. Slowly growing and asymptomatic metastases can be monitored with follow-up while receiving thyroid-stimulating hormone (TSH) suppression therapy. In patients with a limited number of lung metastases and good performance status, surgical removal of the metastatic lesions may be considered. Systemic therapy should be considered for patients with progressive RAI refractory DTC. In this clinical guideline, we aim to outline the treatment principles for patients with lung, bone, and brain metastases of DTC.

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

Purpose: To investigate the characteristics and treatment results of patients aged ≥ 85 years who were diagnosed with treatment-naïve neovascular age-related macular degeneration (nAMD). Methods: The medical records of patients diagnosed with treatment-naïve nAMD who were ≥ 85 years old at the time of diagnosis with at least 12 months follow-up were retrospectively reviewed. The number of intravitreal injections of anti-vascular endothelial growth factor (VEGF) and agents used during the entire period were investigated. Best-corrected visual acuity and optical coherence tomography results before and after treatment were analyzed. Visual acuity of the fellow eye was also collected. Results: A total of 40 eyes of 40 patients with mean age of 87.5 ± 2.4 were included in the study. The mean logarithm of the minimal angle of resolution visual acuity was 0.85 ± 0.57, and the mean of the fellow eye was 0.93 ± 0.99. Compared to before the treatment, there was no significant difference after intravitreal injection in terms of visual acuity. Central retinal thickness showed significant reduction at all time points after treatment. Conclusions In patients aged ≥ 85 years at the time of diagnosis, intravitreal injections of anti-VEGF prevented deterioration of visual acuity and showed successful anatomical outcomes. Especially, many had poor visual acuity in the fellow eye, suggesting the importance of maintaining visual acuity. Therefore, active treatment is necessary in the elderly.

Purpose: The da Vinci single-port (SP) system has been used in various surgical fields, including colorectal surgery.However, limited experience has been reported on its safety and feasibility. This study aims to evaluate the short-term outcomes of SP robotic surgery for the treatment of rectal cancer compared with multiport (MP) robotic surgery. Methods: Rectal cancer patients who underwent curative resection in 2020 were reviewed. A total of 43 patients underwent robotic total mesorectal excision (TME), of which 26 (13 in each group, SPTME vs. MPTME) were included in the case-matched cohort for analysis. Intraoperative and postoperative outcomes and pathological results were compared between the 2 groups. Results: Median tumor height was similar between the 2 groups (SPTME vs. MPTME : 5.9 cm [range, 2.2–9.6 cm] vs. 6.7 cm [range, 3.4–10.0 cm], P = 0.578). Preoperative chemoradiotherapy was equally performed (38.5%). The median estimated blood loss was less (20.0 mL [range, 5.0–20.0 mL] vs. 30.0 mL [range, 20.0–30.0 mL], P = 0.020) and the median hospital stay was shorter (7 days [range, 6–8 days] vs. 8 days [range, 7–9 days], P = 0.055) in the SPTME group. Postoperative complications did not differ (SPTME vs. MPTME : 7.7% vs. 23.1%, P = 0.587). One patient in the SPTME group and 3 in the MPTME group experienced anastomotic leakage. Conclusion SP robotic TME showed perioperative outcomes similar to MP robotic TME. The SP robotic system can be considered a surgical option for the treatment of rectal cancer. Further prospective randomized trials with larger cohorts are required.

Purpose: This study investigated the utility of second-line contrast-enhanced ultrasonography (CEUS) using Sonazoid in Liver Imaging Reporting and Data System category 3 (LR-3) and 4 (LR-4) observations on gadoxetate-enhanced magnetic resonance imaging (MRI). Methods: This retrospective study included LR-3 or LR-4 observations on gadoxetate-enhanced MRI subsequently evaluated with CEUS from 2013 to 2017. The presence of MRI features, CEUSarterial phase hyperenhancement (CEUS-APHE), and Kupffer phase defect (KPD) was evaluated. Multivariable logistic regression analysis was performed to identify significant imaging features associated with the diagnosis of hepatocellular carcinoma (HCC). The optimal diagnostic criteria were investigated using the McNemar test. Results: In total, 104 patients with 104 observations (63 HCCs) were included. The presence of both CEUS-APHE and KPD on CEUS enabled the additional detection of 42.3% (11/26) of LR-3 HCCs and 78.4% (29/37) of LR-4 HCCs. Transitional phase (TP) hypointensity (adjusted odds ratio [OR], 10.59; P<0.001), restricted diffusion (adjusted OR, 7.55; P=0.004), and KPD (adjusted OR, 7.16; P=0.003) were significant imaging features for HCC diagnosis. The presence of at least two significant imaging features was optimal for HCC diagnosis (sensitivity, specificity, and accuracy: 88.9%, 78.1%, and 84.6%, respectively), with significantly higher sensitivity than the presence of both CEUS-APHE and KPD (sensitivity, specificity, and accuracy: 63.5% [P=0.001], 92.7% [P=0.077], and 75.0% [P=0.089], respectively). Conclusion The combined interpretation of gadoxetate-enhanced MRI and second-line CEUS using Sonazoid, focusing on TP hypointensity, restricted diffusion, and KPD, may be optimal for further characterizing LR-3 and LR-4 observations.

Background/Aims: Despite proper use of pharmaceuticals, adverse drug reactions (ADRs) can lead to problems related to patient safety. We analyzed the characteristics of ADRs, particularly serious adverse events (SAEs), in a single tertiary medical institution. Methods: Spontaneous ADR report data collected from 2010 to 2019 in Seoul National University Hospital were assessed. Causality was evaluated according to the World Health Organization-Uppsala Monitoring Centre criteria. Age, sex, onset, severity, seriousness, and system organ class (SOC) of ADRs and SAEs were analyzed. Results: During the study period, a total of 49,955 individual case safety reports were assessed as possible, probable, or certain. Although the number of gastrointestinal ADR reports was high (25.9%), severe cases were uncommon (2.6%). By contrast, the number of hematologic disorders was low (6.6%) but 39.2% of them were severe. Among ADRs, 10.2% were assessed as SAEs, the proportion of which was high at extreme ages and in males. Body as a whole-general disorders were the most frequently reported SOC for SAEs, followed by skin and appendage disorders. Antineoplastic agents and antibiotics were the most common causative agents of SAEs and ADRs. Anaphylactic reaction was the most frequent SAE (6.5%). Conclusions The proportion of SAE differs according to SOC and drug. Attention should be paid to SAEs in children and older adults because the rate of SAEs is significantly higher at extreme ages.

Objective: To intraindividually compare hepatocellular carcinoma (HCC) washout between MRIs using hepatobiliary agent (HBA) and extracellular agent (ECA). Materials and Methods: This study included 114 prospectively enrolled patients with chronic liver disease (mean age, 55 ± 9 years; 94 men) who underwent both HBA-MRI and ECA-MRI before surgical resection for HCC between November 2016 and May 2019. For 114 HCCs, the lesion-to-liver visual signal intensity ratio (SIR) using a 5-point scale (-2 to +2) was evaluated in each phase. Washout was defined as negative visual SIR with temporal reduction of visual SIR from the arterial phase. Illusional washout (IW) was defined as a visual SIR of 0 with an enhancing capsule. The frequency of washout and MRI sensitivity for HCC using LR-5 or its modifications were compared between HBA-MRI and ECA-MRI. Subgroup analysis was performed according to lesion size (< 20 mm or ≥ 20 mm). Results: The frequency of portal venous phase (PP) washout with HBA-MRI was comparable to that of delayed phase (DP) washout with ECA-MRI (77.2% [88/114] vs. 68.4% [78/114]; p = 0.134). The frequencies were also comparable when IW was allowed (79.8% [91/114] for HBA-MRI vs. 81.6% [93/114] for ECA-MRI; p = 0.845). The sensitivities for HCC of LR-5 (using PP or DP washout) were comparable between HBA-MRI and ECA-MRI (78.1% [89/114] vs. 73.7% [84/114]; p = 0.458). In HCCs < 20 mm, the sensitivity of LR-5 was higher on HBA-MRI than on ECA-MRI (70.8% [34/48] vs. 50.0% [24/48]; p = 0.034). The sensitivity was similar to each other if IW was added to LR-5 (72.9% [35/48] for HBA-MRI vs. 70.8% [34/48] for ECA-MRI; p > 0.999). Conclusion Extracellular phase washout for HCC diagnosis was comparable between MRIs with both contrast agents, except for tumors < 20 mm. Adding IW could improve the sensitivity for HCC on ECA-MRI in tumors < 20 mm.

Background/Aims: Despite proper use of pharmaceuticals, adverse drug reactions (ADRs) can lead to problems related to patient safety. We analyzed the characteristics of ADRs, particularly serious adverse events (SAEs), in a single tertiary medical institution. Methods: Spontaneous ADR report data collected from 2010 to 2019 in Seoul National University Hospital were assessed. Causality was evaluated according to the World Health Organization-Uppsala Monitoring Centre criteria. Age, sex, onset, severity, seriousness, and system organ class (SOC) of ADRs and SAEs were analyzed. Results: During the study period, a total of 49,955 individual case safety reports were assessed as possible, probable, or certain. Although the number of gastrointestinal ADR reports was high (25.9%), severe cases were uncommon (2.6%). By contrast, the number of hematologic disorders was low (6.6%) but 39.2% of them were severe. Among ADRs, 10.2% were assessed as SAEs, the proportion of which was high at extreme ages and in males. Body as a whole-general disorders were the most frequently reported SOC for SAEs, followed by skin and appendage disorders. Antineoplastic agents and antibiotics were the most common causative agents of SAEs and ADRs. Anaphylactic reaction was the most frequent SAE (6.5%). Conclusions The proportion of SAE differs according to SOC and drug. Attention should be paid to SAEs in children and older adults because the rate of SAEs is significantly higher at extreme ages.

Objective: To intraindividually compare hepatocellular carcinoma (HCC) washout between MRIs using hepatobiliary agent (HBA) and extracellular agent (ECA). Materials and Methods: This study included 114 prospectively enrolled patients with chronic liver disease (mean age, 55 ± 9 years; 94 men) who underwent both HBA-MRI and ECA-MRI before surgical resection for HCC between November 2016 and May 2019. For 114 HCCs, the lesion-to-liver visual signal intensity ratio (SIR) using a 5-point scale (-2 to +2) was evaluated in each phase. Washout was defined as negative visual SIR with temporal reduction of visual SIR from the arterial phase. Illusional washout (IW) was defined as a visual SIR of 0 with an enhancing capsule. The frequency of washout and MRI sensitivity for HCC using LR-5 or its modifications were compared between HBA-MRI and ECA-MRI. Subgroup analysis was performed according to lesion size (< 20 mm or ≥ 20 mm). Results: The frequency of portal venous phase (PP) washout with HBA-MRI was comparable to that of delayed phase (DP) washout with ECA-MRI (77.2% [88/114] vs. 68.4% [78/114]; p = 0.134). The frequencies were also comparable when IW was allowed (79.8% [91/114] for HBA-MRI vs. 81.6% [93/114] for ECA-MRI; p = 0.845). The sensitivities for HCC of LR-5 (using PP or DP washout) were comparable between HBA-MRI and ECA-MRI (78.1% [89/114] vs. 73.7% [84/114]; p = 0.458). In HCCs < 20 mm, the sensitivity of LR-5 was higher on HBA-MRI than on ECA-MRI (70.8% [34/48] vs. 50.0% [24/48]; p = 0.034). The sensitivity was similar to each other if IW was added to LR-5 (72.9% [35/48] for HBA-MRI vs. 70.8% [34/48] for ECA-MRI; p > 0.999). Conclusion Extracellular phase washout for HCC diagnosis was comparable between MRIs with both contrast agents, except for tumors < 20 mm. Adding IW could improve the sensitivity for HCC on ECA-MRI in tumors < 20 mm.