• Journal of Gastric Cancer
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• v.16 no.4
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• pp.215-220
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• 2016

Purpose: This study aimed to evaluate the rate, patterns, and risk factors associated with tumor recurrence in patients with T1N0 gastric cancer. Materials and Methods: The medical records of 8,753 patients with pathological T1N0M0 gastric cancer who underwent gastrectomy between 1994 and 2014 at Sungkyunkwan University School of Medicine were examined. Results: Among the 8,753 patients, 95 patients (1.1%) experienced tumor recurrence; this included 31 remnant, 27 hematogenous, 9 lymph nodal, 5 peritoneal, and 23 multiple-site recurrences. When patients were divided into two groups according to the presence of tumor recurrence, the following characteristics were higher in the recurrence group than in the non-recurrence group: older age (${\geq}65years$), male gender, undifferentiated histology, submucosal invasion, and venous invasion. In multivariate analysis, older age, male gender, tumor depth (sm2 and sm3 invasion), and venous invasion were independent risk factors for tumor recurrence. The recurrence rates were 0.7% in patients with less than two risk factors, 1.7% in those with two risk factors, 3.0% in those with three risk factors, and 6.3% in those with four risk factors (P<0.001). Conclusions: Although tumor recurrence is rare in pT1N0M0 gastric cancer, some patients with certain risk factors demonstrate an increased rate of tumor recurrence. Careful follow-up is required for patients with three or four risk factors.

• Genomics & Informatics
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• v.15 no.1
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• pp.48-50
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• 2017

Tumor tissues from biopsies or surgery are major sources for the next generation sequencing (NGS) study, but these procedures are invasive and have limitation to overcome intratumor heterogeneity. Recent studies have shown that driver alterations in tumor tissues can be detected by liquid biopsy which is a less invasive technique capable of both capturing the tumor heterogeneity and overcoming the difficulty in tissue sampling. However, it is still unclear whether the driver alterations in liquid biopsy can be detected by targeted NGS and how those related to the tissue biopsy. In this study, we performed whole-exome sequencing for a breast cancer tissue and identified PTEN p.H259fs*7 frameshift mutation. In the plasma DNA (liquid biopsy) analysis by targeted NGS, the same variant initially identified in the tumor tissue was also detected with low variant allele frequency. This mutation was subsequently validated by digital polymerase chain reaction in liquid biopsy. Our result confirm that driver alterations identified in the tumor tissue were detected in liquid biopsy by targeted NGS as well, and suggest that a higher depth of sequencing coverage is needed for detection of genomic alterations in a liquid biopsy.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.47-53
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• 1996

Synovial sarcoma is an uncommon malignant soft tissue tumor which usually occurs in young-aged person, and frequently involves the lower extremities. Many authors recommended wide excision, adjuvant chemotherapy and radiation therapy. The proposed factors that affect the prognosis are age, size of tumor, site of tumor in the body, depth of tumor, histologic grade and method of treatment. The purpose of the study is to analyze the factors that affect the 5-year survival rate. We retrospectively evaluated 19 cases of synovial sarcoma treated in the Kosin University Medical Center from Jan. 1982 to Dec. 1994. The overall 5-year survival rate was 47.6% and the 5-year survival rates were significantly higher(P<0.05) in the group with smaller size of mass. The significantly lower 5-year survival rates were observed in the patient with deeply located lesion and with higher histologic grade. The 5-year survival rates were higher in the patients treated with wide excision than in the patients treated with amputation. But there was no significant difference between these groups. The adjuvant chemotherapy and radiotherapy were performed. In conclusion, we suggest that the better prognosis will be observed in the patients with smaller size of tumor mass, superficially located and lower histologic grade.

• Brain Tumor Research and Treatment
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• v.6 no.2
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• pp.47-53
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• 2018

Brain tumors represent a diverse spectrum of histology, biology, prognosis, and treatment options. Although MRI remains the gold standard for morphological tumor characterization, positron emission tomography (PET) can play a critical role in evaluating disease status. This article focuses on the use of PET with radiolabeled glucose and amino acid analogs to aid in the diagnosis of tumors and differentiate between recurrent tumors and radiation necrosis. The most widely used tracer is $^{18}F$-fluorodeoxyglucose (FDG). Although the intensity of FDG uptake is clearly associated with tumor grade, the exact role of FDG PET imaging remains debatable. Additionally, high uptake of FDG in normal grey matter limits its use in some low-grade tumors that may not be visualized. Because of their potential to overcome the limitation of FDG PET of brain tumors, $^{11}C$-methionine and $^{18}F$-3,4-dihydroxyphenylalanine (FDOPA) have been proposed. Low accumulation of amino acid tracers in normal brains allows the detection of low-grade gliomas and facilitates more precise tumor delineation. These amino acid tracers have higher sensitivity and specificity for detecting brain tumors and differentiating recurrent tumors from post-therapeutic changes. FDG and amino acid tracers may be complementary, and both may be required for assessment of an individual patient. Additional tracers for brain tumor imaging are currently under development. Combinations of different tracers might provide more in-depth information about tumor characteristics, and current limitations may thus be overcome in the near future. PET with various tracers including FDG, $^{11}C$-methionine, and FDOPA has improved the management of patients with brain tumors. To evaluate the exact value of PET, however, additional prospective large sample studies are needed.

• Journal of Gastric Cancer
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• v.14 no.2
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• pp.111-116
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• 2014

Purpose: The standard surgical procedure recommended to treat gastric cancer in advanced cases is dissection of D2 lymph nodes (LNs). However, the optimum number of LNs that should be retrieved in advanced gastric cancer (AGC) remains debatable. Therefore, this study aimed to investigate the optimum number of retrieved LNs and determine the clinical implications of retrieved LN numbers on the treatment of AGC. Materials and Methods: Of 575 AGC patients reviewed, 369 who underwent open curative gastrectomy with D2 or more extensive LN dissection at our institution were analyzed according to their clinicopathologic characteristics and number of LNs retrieved. Results: Multivariate regression analysis revealed that tumor size (P=0.006), depth of invasion (P=0.000), LN metastasis (P=0.000), and stage (P=0.000) were independent variables with predictive value. The 5-year survival rates were differed significantly according to the numbers of LNs retrieved ([1] 15~25 vs. >25 and [2] 15~39 vs. ${\geq}40$) in patients with differentiated carcinoma. Conclusions: Tumor size, depth of invasion, LN metastasis, and stage were independent predictive factors for survival. The number of retrieved LNs was significantly associated with a long-term survival benefit in patients with differentiated carcinoma. Therefore, our data suggest that the retrieval of a minimum of 15 LNs may not be sufficient to warrant a recommendation for further curative surgery and that extensive LN dissection should be considered in advanced carcinoma of the differentiated type.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3141-3145
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• 2015

Background: Gastric cancer (GC) is one the common lethal cancers in Iran. Detection of GC in the early stages would assesses to improve the survival of patients. In this study, we attempt to evaluate the accuracy of EUS in detection depth of invasion of GC among Iranian Patients. Materials and Methods: This study is a retrospective study of patients with pathologically confirmed GC. They underwent EUS before initiating the treatment. The accuracy of EUS and agreement between the two methods was evaluated by comparing pre treatment EUS finding with post operative histopathological results. Results: The overall accuracy of EUS for T and N staging was 67.9% and 75.47, respectively. Underestimation and overestimation was seen in 22 (14.2%) and 40 (25.6%) respectively. The EUS was more accurate in large tumors and the tumors located in the middle and lower parts of the stomach. The EUS was more sensitive in T3 staging. The values of weighted Kappa from the T and N staging were 0.53 and 0.66, respectively. Conclusions: EUS is a useful modality for evaluating the depth of invasion of GC. The accuracy of EUS was higher if the tumor was located in the lower parts of the stomach and the size of the tumor was more than 3 cm. Therefore, judgments made upon other criteria evaluated in this study need to be reconsidered.

• Journal of Gastric Cancer
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• v.12 no.2
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• pp.81-87
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• 2012

Purpose: The aim of the present study was to assess the association between the pre-operative plasma fibrinogen level and the adjacent organ involvement in advanced gastric cancer. Materials and Methods: A total of 923 pre-operative plasma samples were obtained from 923 patients diagnosed clinically as having advanced gastric cancer, and fibrinogen levels were measured by immunoassay. Associations between fibrinogen levels and clinicopathologic findings (depth of tumor, adjacent organ involvement, and lymph node metastasis), along with survival were examined by univariate and multivariate analyses. Results: Tumor size, tumor depth, and the presence of lymph node metastasis were found to be positively correlated with the preoperative plasma fibrinogen levels (P<0.001). Fifty (5.4%) patients had adjacent organ involvement. Lymphatic invasion (P<0.001), tumor size (P<0.001), clinical T (depth of invasion) stage (P<0.001), and clinical nodal stage (P=0.018) were found to be associated with adjacent organ involvement. Univariate and multivariate regression analyses showed that a preoperatively elevated plasma fibrinogen level was associated with adjacent organ involvement (P<0.001, 0.028), and Kaplan-Meier analysis showed that it was associated with poorer survival (P<0.001). Conclusions: Plasma fibrinogen was found to be a clinically useful marker of adjacent organ involvement and overall survival. When a high fibrinogen level is encountered, preoperatively, adjacent organ involvement should be suspected in clinically advanced gastric cancer.

• The Journal of the Korean bone and joint tumor society
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• v.18 no.2
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• pp.72-77
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• 2012

Purpose: Unplanned excision of a soft tissue sarcoma is defined as the operation performed for gross removal of a soft tissue sarcoma without regard for preoperative imaging or the necessity to removal a margin of normal tissue covering the cancer. We report our experience of treating primary soft tissue sarcoma after an unplanned excision. Materials and Methods: We retrospectively reviewed 31 patients referred to our hospital after unplanned excision at other hospitals for treatment of a STS. The clinical information was reviewed with a focus on the patient's age, gender, tumor location, tumor size, tumor depth, presumptive diagnoses at the previous surgery, refer hospital, definitive diagnosis, interval between the initial and additional surgery and local recurrence. Results: There were 19 males and 12 females with a median age of 48 years (range, 17-75 years) at the time of referral. Seventeen patients (54.8%) had tumors in their lower limb, 6 (19.4%) had tumors in their upper limb, and 8 (25.8%) had tumors in their trunk. Tumor depth could be determined for 8 patients (25.8%), with superficial and 22 deep tumors (71%). The medial interval between unplanned excision to re-excision ranged from 2 weeks to 1 year (median, 5 weeks). Local recurrence was detected in 2 patients. All patients were alive without metastasis at last follow up. Conclusion: Even in upper class general hospital, many unplanned excision had been performed, which is considered to be avoided. When the relatively huge mass located in deeper layer it requires enough preoperative imaging studies and biopsy.

• Progress in Medical Physics
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• v.16 no.2
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• pp.104-109
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• 2005

Photodynamic therapy (PDT) is one of the expectable current cure operation methods. Tumor tissue is treated by abundant oxygen in a body and generated singlet or free radical from exterior laser diode and photosensitizer. Current problem of PDT is the low penetration power of the light beam in a deep seated large tumor and solid tumor thus results in low treatment outcome. In the study, we tried to develop interstitial photodynamics therapy treatment to solve this problem. As the accurate determination of light dosimetry in biological tissue is one of the most important factors affecting the effectiveness of PDT, parameters used in this study are the optical property of biological tissue. Since biological tissues have large scattering coefficient to visible light the penetration depth of a biological tissue in visible light region is only $15\~20$ mm. We showed that it is possible to measure fluence rate and penetration depth within the biological tissues by Monte Carlo simulation very well. Based on the MC simulation study, the effectiveness of interstitial photodynamic therapy on tumor control in solid tumor was proved through in vivo animal experiment.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.340-342
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• 2001

본 논문은 유방질환 중에서 Duct(관)에 발생하는 유방 종양을 benign(양성종양)/DCIS (Ductal Carcinoma In Situ)/NOS(Invasive ductal carcinoma)로 자동 분류하기 위한 분류방법을 제안한다. 분류기 생성에서 가장 중요한 단계인 특징 추출단계에서는 wavelet 변환을 적용하였으며, wavelet 변환의 각 depth에 따라 분류기를 생성하여, depth와 생성된 분류기의 분류 정확도와의 상관관계를 비교.분석하였다. 현미경 100배 배율과 400배 배율의 유방 질환 영상을 1, 2, 3, 4단계(depth)의 wavelet 변환을 적용한 후, 분할된 서브밴드에서 GLCM을 이용하여 질감 특징(Entropy, Energy, Contrast, Homogeneity)을 추출하여, 이 특징값들을 조합하여 판별분석에 의해 분류기(classifier)를 생성한 후, 분류 정확도를 검증하였다. Benign/DCIS/NOS를 분류하려면 최소 3단계 이상의 wavelet 변환을 적용해야 하고, 400배 배율 영상보다는 100배 배율의 영상이 더 나은 결과를 보였다.