Bong Keun Choe

Pelvic Bone Complications After Radiation Therapy of Uterine Cervical Cancer: Evaluation with MRI

OBJECTIVE The purpose of this study was to assess the prevalence and distribution of radiation-induced insufficiency fractures and to investigate other bony complications of the female pelvis associated with radiation therapy using MR images. MATERIALS AND METHODS Two radiologists retrospectively evaluated pelvic MR images of 510 patients (mean age, 54.7 years) who underwent pelvic irradiation for uterine cervical cancer for the presence and location of insufficiency fractures by consensus. We calculated the cumulative prevalence of pelvic insufficiency fractures on the basis of their results. In addition, we identified other associated bony complications of the female pelvis by reviewing the MR images. RESULTS Insufficiency fractures were diagnosed in 100 patients; the 5-year cumulative prevalence was 45.2%. An insufficiency fracture was diagnosed a median of 16.9 months after radiation therapy. The fracture sites were the sacrum body and alae, medial side of the iliac bone, the roof of the acetabulum, superior rami of the pubic bone, femoral heads, and L5 vertebra. Sixty-one patients (61%) developed multiple fractures, and among them, 40 (40%) had bilateral symmetric lesions of the sacral alae. Other complications associated with the radiation therapy, as determined by evaluation of the MR images, were osteolysis and avascular necrosis of the femoral head. CONCLUSION Radiation-induced pelvic insufficiency fractures are a frequent complication of radiation therapy for uterine cervical cancer. Osteolysis and avascular necrosis of the femoral head were also diagnosed using MRI after radiation therapy.

Health and economic burden of major cancers due to smoking in Korea

Cigarette smoking is one of the most important public health concerns in Korea and worldwide. A number of studies have been conducted to measure the health and economic burden of smoking, but these did not reflect recent changes such as the decrease in smoking rate and the increase in the incidence of cancer. The purpose of this study was to provide up-to-date estimates of the health and economic burden of cancer caused by smoking and to compare the results with those of previous studies. Cancer-related burden was assessed with nationally representative data such as claims data from the National Health Insurance Corporation, and cause of death records from the National Statistical Office and the Korea Health Panel. We determined the smoking-attributable burden by multiplying the smoking-attributable fraction by the total burden. As a result, the burden of major cancers due to smoking was found to be substantial despite a recent sharp decrease in smoking by the Korean population. The total economic cost reaches

Tumor spatial heterogeneity in myxoid-containing soft tissue using texture analysis of diffusion-weighted MRI

2,234.0 million in males and

A missense polymorphism (rs11895564, Ala380Thr) of integrin alpha 6 is associated with the development and progression of papillary thyroid carcinoma in Korean population

870.0 million in females. Also, the health burden of cancers due to smoking is 2,038.9 disability adjusted life years (DALYs) per 100,000 individuals in men and 732.2 DALYs per 100,000 individuals in women. Among all cancers, cancers of the trachea, lungs and bronchus are the leading causes of health and economic burden. The huge burden caused by cancers linked to smoking makes it imperative that adequate policies to decrease the prevalence of smoking be developed, particularly considering the recent increase in smoking rate among women.

Suppression of GLTSCR2 expression in renal cell carcinomas.

The objective of this study was to examine the tumor spatial heterogeneity in myxoid-containing soft-tissue tumors (STTs) using texture analysis of diffusion-weighted imaging (DWI). A total of 40 patients with myxoid-containing STTs (23 benign and 17 malignant) were included in this study. The region of interest (ROI) was manually drawn on the apparent diffusion coefficient (ADC) map. For texture analysis, the global (mean, standard deviation, skewness, and kurtosis), regional (intensity variability and size-zone variability), and local features (energy, entropy, correlation, contrast, homogeneity, variance, and maximum probability) were extracted from the ADC map. Student’s t-test was used to test the difference between group means. Analysis of covariance (ANCOVA) was performed with adjustments for age, sex, and tumor volume. The receiver operating characteristic (ROC) analysis was performed to compare diagnostic performances. Malignant myxoid-containing STTs had significantly higher kurtosis (P = 0.040), energy (P = 0.034), correlation (P<0.001), and homogeneity (P = 0.003), but significantly lower contrast (P<0.001) and variance (P = 0.001) compared with benign myxoid-containing STTs. Contrast showed the highest area under the curve (AUC = 0.923, P<0.001), sensitivity (94.12%), and specificity (86.96%). Our results reveal the potential utility of texture analysis of ADC maps for differentiating benign and malignant myxoid-containing STTs.

Interposition of the Posterior Cruciate Ligament into the Medial Compartment of the Knee Joint on Coronal Magnetic Resonance Imaging

Purpose Integrins play crucial roles in the pathogenesis of papillary thyroid carcinoma (PTC). The aim of this study was to investigate whether two single nucleotide polymorphisms (SNPs) (rs2141698, -1687A/G; rs11895564, Ala380Thr) of the integrin alpha 6 (ITGA6) gene are associated with the development and clinicopathologic characteristics of PTC such as the size (<1 cm and ≥1 cm), number (unifocality and multifocality), location (one lobe and both lobes), extrathyroid invasion, and cervical lymph node metastasis. Methods We enrolled 104 PTC patients and 318 control subjects. Genotypes of each SNP were determined by direct sequencing. SNPStats, SNPAnalyzer, and Helixtree programs were used to evaluate odds ratios (ORs), 95% confidence intervals (CIs), and P-values. Multiple logistic regression models were performed to analyze genetic data. Results A missense SNP rs11895564 was associated with the development of PTC. The A allele frequency of rs11895564 was higher in PTC patients than in controls (13.5% vs. 7.1%; P = 0.005; OR, 2.04; 95% CI, 1.24 to 3.37). In the clinicopathologic characteristics, the A allele frequency of rs11895564 showed difference in the size (19.6% in <1 cm vs. 6.9% in ≥1 cm; P = 0.010; OR, 0.30; 95% CI, 0.12 to 0.75) and number (8.5% in unifocality vs. 20.8% in multifocality; P = 0.015; OR, 2.85; 95% CI, 1.23 to 6.59) of PTC. Conclusion These results suggest that the A allele of rs11895564 (Ala380Thr) in ITGA6 may be a risk factor of PTC, and also contribute to the progression of PTC in the Korean population.

l-myc Polymorphism in Gastric Cancer, Lung Cancer, and Hepatocellular Carcinoma

Nucleolar protein PICT-1/GLTSCR2 (GLTSCR2) has both tumor suppressive and oncogenic activities, depending on the types of cancer tissue and its expression level. The role of GLTSCR2 in renal cell carcinoma (RCC) has not yet been addressed. The aims of this study were to evaluate GLTSCR2 expression in RCC tissue and to determine pathological significance of GLTSCR2 in terms of tumor grade. RCC and adjacent normal tissue from 84 different patients was retrieved from nephrectomy specimens. The expression level of GLTSCR2 in RCC tissues was determined via immunohistochemical staining and invasion was determined using transwell chambers with Matrigel-coated membranes. The expression of GLTSCR2 was suppressed in about 80% of the carcinoma specimens compared to noncancerous renal tissue and inversely correlated with Fuhrman nuclear grade (r=-0.40, p<0.05). Knockdown of GLTSCR2 expression increased the invasiveness of SNU267 RCC cells. The expression of GLTSCR2 was suppressed in RCCs and its downregulation accentuated the malignant phenotype.

Increases in cell proliferation and apoptosis in dentate gyrus of anorexia (anx/anx) mice.

Objective The purpose of our study was to evaluate the overall prevalence and clinical significance of interposition of the posterior cruciate ligament (PCL) into the medial compartment of the knee joint in coronal magnetic resonance imaging (MRI). Materials and Methods We retrospectively reviewed 317 consecutive patients referred for knee MRI at our institution between October 2009 and December 2009. Interposition of the PCL into the medial compartment of the knee joint on proton coronal MRI was evaluated dichotomously (i.e., present or absent). We analyzed the interposition according to its prevalence as well as its relationship with right-left sidedness, gender, age, and disease categories (osteoarthritis, anterior cruciate ligament tear, and medial meniscus tear). Results Prevalence of interposition of PCL into the medial compartment of the knee joint was 47.0% (149/317). There was no right (50.0%, 83/166) to left (43.7%, 66/151) or male (50.3%, 87/173) to female (43.1%, 62/144) differences in the prevalence. There was no significant association between the prevalence and age, or the disease categories. Conclusion Interposition of the PCL into the medial compartment of the knee joint is observed in almost half of patients on proton coronal MRI of the knee. Its presence is not associated with any particular factors including knee pathology and may be regarded as a normal MR finding.

Is Lesion Size an Independent Indication for Endoscopic Resection of Biopsy-Proven Low-Grade Gastric Dysplasia?

PURPOSE This study was performed to see if a particular polymorphism in the l-myc, a nuclear oncogene at the 1p32 locus, might be associated with greater risk of gastric cancer, lung cancer and hepatocellular carcinomas (HCC) in Korean patients. MATERIALS AND METHODS Genomic DNA, derived from patients diagnosed with gastric cancer (n=57), lung cancer (n=39), HCC (n=35) and healthy individuals (n= 176), was examined. The l-myc polymorphism under study was visualized by PCR followed by EcoRI digestion. RESULTS There was no significant difference in the distribution of the l-myc polymorphism genotypes and allele frequencies between the cancer patients and the controls. CONCLUSION The l-myc polymorphism does not appear to be indicative of elevated risk of cancers of the stomach, lung and HCC.