• Journal of the Korean Society of Radiology
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• v.83 no.6
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• pp.1240-1258
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• 2022

The lymphatic system provides a route for the spread of inflammation and malignancies. The identification of nodal stations and lymphatic pathways of tumor spread is important for tumor staging, choice of therapy, and the prediction of the prognosis of patients with malignant diseases. Because lymph node metastasis is common in primary intra-abdominal malignant tumors, its detection is essential for radiologists to understand the pattern of disease spread. Using schematic pictures and color-coded CT images, this pictorial essay describes the locations and nomenclature of the abdominal lymph nodes. Furthermore, the lymphatic drainage pathways of the upper and lower gastrointestinal tracts, liver, gallbladder, bile duct, and pancreas have been highlighted. In addition, lymph nodes belonging to the regional lymph nodes in malignant tumors arising from each organ are described, and certain cases are presented with images from patients.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.808-829
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• 2022

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively on multiphasic CT and MRI based on its distinctive imaging findings. These features include arterial phase hyperenhancement and washout on portal or delayed phase images. However, radiologists face significant diagnostic challenges because some HCCs exhibit atypical imaging characteristics. In addition to many HCC-mimicking lesions, such as arterioportal shunts, combined HCC-cholangiocarcinoma, intrahepatic cholangiocarcinoma, and hemangioma present a challenge for radiologists in actual clinical practice. The ability to distinguish HCCs from mimickers on initial imaging examinations is crucial for appropriate management and treatment decisions. Therefore, this pictorial review presents the imaging findings of atypical HCCs and HCCs mimicking malignant and benign lesions and discusses important clues that may help narrow down the differential diagnosis.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.999-1008
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• 2023

Thyroid cancer, characterized by high incidence rates, good prognosis, and frequent recurrence, is typically treated surgically. However, since the early 2000s, radiofrequency ablation, which is commonly utilized in liver, lung, and kidney cancers, is being performed for management of primary and recurrent thyroid cancers. Many studies have focused on inoperable cases of low-risk papillary microcarcinoma (≤ 1 cm) and some have investigated its role in larger lesions (up to 4 cm). Overall, these studies have reported positive results. Radiofrequency ablation for recurrent cancer has primarily been performed for locally recurrent cervical cancer, and this therapeutic approach has been attempted for treatment of distant metastases in lungs and bones, with encouraging outcomes. A growing global trend, particularly in South Korea, the United States, and Europe supports radiofrequency ablation for thyroid cancer. However, this therapy is currently not recognized as a treatment option recommended by universally accepted clinical guidelines such as those established by the National Comprehensive Cancer Network. Based on past efforts and future research, radiofrequency ablation is expected to play a key role in thyroid cancer treatment in the near future.

• Korean Journal of Radiology
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• v.22 no.5
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• pp.714-724
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• 2021

Objective: To evaluate the value of ¹⁸F-fluorodeoxyglucose PET/MRI added to contrast-enhanced CT (CECT) in initial staging, assessment of resectability, and postoperative follow-up of biliary tract cancer. Materials and Methods: This retrospective study included 100 patients (initial workup [n = 65] and postoperative follow-up [n = 35]) who had undergone PET/MRI and CECT for bile duct or gallbladder lesions between January 2013 and March 2020. Two radiologists independently reviewed the CECT imaging set and CECT plus PET/MRI set to determine the likelihood of malignancy, local and overall resectability, and distant metastasis in the initial workup group, and local recurrence and distant metastasis in the follow-up group. Diagnostic performances of the two imaging sets were compared using clinical-surgical-pathologic findings as standards of reference. Results: The diagnostic performance of CECT significantly improved after the addition of PET/MRI for liver metastasis (area under the receiver operating characteristic curve [A_z]: 0.77 vs. 0.91 [p = 0.027] for reviewer 1; 0.76 vs. 0.92 [p = 0.021] for reviewer 2), lymph node metastasis (0.73 vs. 0.92 [p = 0.004]; 0.81 vs. 0.92 [p = 0.023]), and overall resectability (0.79 vs. 0.92 [p = 0.007]; 0.82 vs. 0.94 [p = 0.021]) in the initial workup group. In the follow-up group, the diagnostic performance of CECT plus PET/MRI was significantly higher than that of CECT imaging for local recurrence (0.81 vs. 1.00 [p = 0.029]; 0.82 vs. 0.94 [p = 0.045]). Conclusion: PET/MRI may add value to CECT in patients with biliary tract cancer both in the initial workup for staging and determination of overall resectability and in follow-up for local recurrence.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7989-7993
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• 2014

Background: The Khon Kaen Cancer Registry (KKCR) was established in 1984. Previous population-based incidences and survivals of childhood cancer in Thailand were determined using a short cancer registration period. Materials and Methods: Data were retrieved of all children residing in Khon Kaen, between 0-15 years, diagnosed as having cancer and registered in the KKCR (1985-2009). The follow-up censored date was December 31, 2012. The childhood cancers were classified into 12 diagnostic groups, according to the International Classification of Childhood Cancer. The incidence was calculated by the standard method. Survival of childhood cancer was investigated using the KKCR population-based registration data and overall survival calculated using the Kaplan Meier method. Results: In the study period, 912 newly diagnosed cases of childhood cancer were registered. The respective mean and median age was 6.4 (SD=4.6) and 6 (0-14) years. The age-peak for incidence was 0-4 years. The age-standardized rate (ASR) was 83 per million. Leukemia was the most common cancer (N=360, ASR 33.8) followed by neoplasms of the central nervous system (CNS, N=150, ASR 12.8) and lymphoma (N=79, ASR 7.0). The follow-up duration totaled 101,250 months. The death rate was 1.11 per 100 person-months (95%CI: 1.02 -1.20). The 5-year overall survival was 52% (95%CI: 53-56.9) for all cancers. The respective 5-year overall survival for (1) acute lymphoblastic leukemia (ALL), (2) acute non-lymphoblastic leukemia (ANLL), (3) lymphoma, (4) germ cell tumors, (5) renal tumors, (6) retinoblastoma, (7) soft tissue tumors, (8) CNS tumors, (9) bone tumors, (10) liver tumors, and (11) neuroblastoma was (1) 51%, (2) 37%, (3) 63%, (4) 74%, (5) 67%, (6) 55%, (7) 46%, (8) 44%, (9) 36%, (10) 34%, and (11) 25%. Conclusions: The incidence of childhood cancer is lower than those of western countries. Respective overall survival for ALL, lymphoma, renal tumors, liver tumors, retinoblastoma, soft tissue tumors is lower than that reported in developed countries while survival for CNS tumors, neuroblastoma and germ cell tumors is comparable.

• Journal of Gastric Cancer
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• v.17 no.4
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• pp.374-383
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• 2017

Purpose: Bleeding is one of the most serious complications of advanced gastric cancer (AGC) and is associated with a poor prognosis. This study aimed to evaluate the clinical outcomes of endoscopic hemostasis for bleeding in patients with unresectable AGC. Materials and Methods: This study included 106 patients with bleeding associated with gastric cancer who had undergone endoscopic hemostasis between January 2010 and December 2013. Clinical characteristics, treatment outcomes, including rates of successful endoscopic hemostasis and rebleeding, risk factors for rebleeding, and overall survival (OS) were investigated. Results: Successful initial hemostasis was achieved in 83% of patients. Rebleeding occurred in 28.3% of patients within 30 days. The median OS after initial hemostasis was lower in patients with rebleeding than in those without rebleeding (2.7 and 3.9 months, respectively, P=0.02). There were no significant differences in disease status and rebleeding rates among patients with partial response or stable disease (n=4), progressive disease (n=64), and first diagnosis of disease (n=38). Univariate and multivariate analyses (P=0.038 and 0.034, respectively) revealed that transfusion of ${\geq}5$ units of RBCs was a significant risk factor for rebleeding. Conclusions: Despite favorable success rates of endoscopic hemostasis for bleeding associated with gastric cancer, the 30-day rebleeding rate was 28.3% and the median OS was significantly lower in patients with rebleeding than in those without rebleeding. Massive transfusion (${\geq}5$ units of RBCs) was the only significant risk factor for rebleeding. Patients with bleeding associated with AGC who have undergone massive transfusion should be observed closely following endoscopic hemostasis. Further research on approaches to reduce rebleeding rate and prevent death is needed.

• Journal of Gastric Cancer
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• v.16 no.2
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• pp.72-77
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• 2016

Purpose: During laparoscopic gastrectomy, an aberrant left hepatic artery (ALHA) arising from the left gastric artery (LGA) is occasionally encountered. The aim of this study was to define when an ALHA should be preserved during laparoscopic gastrectomy. Materials and Methods: From August 2009 to December 2014, 1,340 patients with early gastric cancer underwent laparoscopic distal gastrectomy. One hundred fifty patients presented with an ALHA; of the ALHA was ligated in 116 patients and preserved in 34 patients. Patient characteristics, postoperative outcomes and perioperative liver function tests were reviewed retrospectively. Correlations between the diameter of the LGA measured on preoperative abdominal computed tomography and postoperative liver enzyme levels were analyzed. Results: Pearson's correlation analysis showed a positive correlation between the diameter of the LGA and serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels on postoperative day 1 in the ALHA-ligated group (P=0.039, P=0.026, respectively). Linear regression analysis estimated the diameter of the LGA to be 5.1 mm and 4.9 mm when AST and ALT levels were twice the normal limit on postoperative day 1. Conclusions: We suggest preserving the ALHA arising from a large LGA, having diameter greater than 5 mm, during laparoscopic gastrectomy to prevent immediate postoperative hepatic dysfunction.

• Radiation Oncology Journal
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• v.34 no.2
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• pp.88-95
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• 2016

Purpose: The purpose of this study was to estimate the clinical utilization of radiation therapy (RT) in Korea between 2009 and 2013. Materials and Methods: We analyzed open claims data from the Health Insurance Review and Assessment Service. The subjects were patients who had diagnostic codes C00-C97 or D00-D48 according to the 10th revision of the International Classification of Diseases, with procedure codes indicating RT treatment. Results: The total number of patients who received RT in 2009, 2010, 2011, 2012, and 2013 were 45,571, 49,593, 54,671, 59,172, and 61,485, respectively. Among them, the total numbers of male and female patients were 20,780/24,791 in 2009, 22,711/26,882 in 2010, 24,872/29,799 in 2011, 27,101/32,071 in 2012, and 27,941/33,544 in 2013. The five cancers that were most frequently treated with RT between 2009 and 2012 were breast, lung, colorectal, liver, and uterine cervical cancers. However, the fifth most common cancer treated with RT that replaced uterine cervical cancer in 2013 was prostate cancer. The three leading types of cancer among the male patients were lung, colorectal, and liver cancers, whereas in female patients, they were breast, uterine cervical, and lung cancers. The type of cancer most commonly treated by RT was cancer of the central nervous system in patients aged 20 years or less, breast cancer in patients aged 30-50 years, and lung cancer in patients aged 60 years or more. Conclusion: Data from this study provided the clinical utilization of RT in Korea between 2009 and 2013.

• Journal of Gastric Cancer
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• v.21 no.2
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• pp.191-202
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• 2021

Purpose: A near-infrared (NIR) fluorescence imaging is a promising tool for cancer-specific image guided surgery. Human epidermal receptor 2 (HER2) is one of the candidate markers for gastric cancer. In this study, we aimed to synthesize HER2-specific NIR fluorescence probes and evaluate their applicability in cancer-specific image-guided surgeries using an animal model. Materials and Methods: An NIR dye emitting light at 800 nm (IRDye800CW; Li-COR) was conjugated to trastuzumab and an HER2-specific affibody using a click mechanism. HER2 affinity was assessed using surface plasmon resonance. Gastric cancer cell lines (NCI-N87 and SNU-601) were subcutaneously implanted into female BALB/c nu (6-8 weeks old) mice. After intravenous injection of the probes, biodistribution and fluorescence signal intensity were measured using Lumina II (Perkin Elmer) and a laparoscopic NIR camera (InTheSmart). Results: Trastuzumab-IRDye800CW exhibited high affinity for HER2 (K_D=2.093(3) pM). Fluorescence signals in the liver and spleen were the highest at 24 hours post injection, while the signal in HER2-positive tumor cells increased until 72 hours, as assessed using the Lumina II system. The signal corresponding to the tumor was visually identified and clearly differentiated from the liver after 72 hours using a laparoscopic NIR camera. Affibody-IRDye800CW also exhibited high affinity for HER2 (K_D=4.71 nM); however, the signal was not identified in the tumor, probably owing to rapid renal clearance. Conclusions: Trastuzumab-IRDye800CW may be used as a potential NIR probe that can be injected 2-3 days before surgery to obtain high HER2-specific signal and contrast. Affibody-based NIR probes may require modifications to enhance mobilization to the tumor site.

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.313-322
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• 2021

Purpose: To find diagnostic image features, to compare diagnostic performance of multiphase CT versus gadoxetic acid disodium-enhanced MRI (GAD-MRI), and to evaluate the impact of analyzing Liver Imaging Reporting and Data System (LI-RADS) imaging features, for distinguishing combined hepatocellular-cholangiocarcinoma (CHC) from hepatocellular carcinoma (HCC). Materials and Methods: Ninety-six patients with pathologically proven CHC (n = 48) or HCC (n = 48), diagnosed June 2008 to May 2018 were retrospectively analyzed in random order by three radiologists with different experience levels. In the first analysis, the readers independently determined the probability of CHC based on their own knowledge and experiences. In the second analysis, they evaluated imaging features defined in LI-RADS 2018. Area under the curve (AUC) values for CHC diagnosis were compared between CT and MRI, and between the first and second analyses. Interobserver agreement was assessed using Cohen's weighted κ values. Results: Targetoid LR-M image features showed better specificities and positive predictive values (PPV) than the others. Among them, rim arterial phase hyperenhancement had the highest specificity and PPV. Average sensitivity, specificity, and AUC values were higher for MRI than for CT in both the first (P = 0.008, 0.005, 0.002, respectively) and second (P = 0.017, 0.026, 0.036) analyses. Interobserver agreements were higher for MRI in both analyses (κ = 0.307 for CT, κ = 0.332 for MRI in the first analysis; κ = 0.467 for CT, κ = 0.531 for MRI in the second analysis), with greater agreement in the second analysis for both CT (P = 0.001) and MRI (P < 0.001). Conclusion: Rim arterial phase hyperenhancement on GAD-MRI can be a good indicator suggesting CHC more than HCC. GAD-MRI may provide greater accuracy than CT for distinguishing CHC from HCC. Interobserver agreement can be improved for both CT and MRI by analyzing LI-RADS imaging features.