• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.9
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• pp.807-814
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• 2013

A fundamental study on laser-tissue interaction was conducted with the aim of developing a therapeutic medical device that can remove lesions on the intestinal wall by irradiating a high-power 808-nm infrared laser light incorporated in an endoscopic system. The perforation depth was linearly increased in the range of 1~4 mm in proportional to laser output (3~12 W) and irradiation time (5~20 s). We demonstrated that the perforation depth during laser irradiation was varied according to the tissue property of each extracted porcine organ. The measurement of the temperature distribution suggests that the energy is localized in the irradiation spot and transferred to deep tissue, which protects the surrounding tissue from thermal injury. These results can be used to set the driving parameters for a laser incision technique as an alternative to conventional surgical interventions.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.665-671
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• 2004

Background: Lymph node metastasis is commonly reported in thoracic esophageal cancer, even in the early esophageal cancer which may be localized only in the mucosa or within the submucosal layer. Although lymph node metastasis greatly influence long-term outcome and cure of the disease, endoscopic mucosal resection or photodynamic therapy without lymph node dissection is widely attempted. The investigation of the pattern of lymph node metastasis and results of surgical resection of superficial esophageal cancer is needed. Material and Method: Pattern of lymph node metastsis and depth of tumor invasion were studied retrospectively from 44 patients with early esophageal cancer who underwent radical resection of the tumor from December, 1995 to August, 2001. Result: Lymph node metastasis was found in 10 patients (22.7%) out of total of 44 patients. Lymph node metastasis was found in 0% (0 of 3), 0% (0 of 4), 50% (2 of 4), and 24.24% (8 of 33) of tumors that invaded the intraepitherium, lamina propria, muscularis mucosa, and submucosa respectively. Anatomically distant lymph node metastases were found more frequently in recurrent laryngeal nerve node(5 cases of 10 patients) and in intraperitoneal node (8 cases of 10). than intrathoracic node (3 cases of 10). There was no operative mortality, however, there were 1 hospital death in patient with lamina propria cancer, 1 late death in patient with submucosal cancer. Three-year survival rates (except hospital death) were 100% in mucosal cancer and 97.0% in submucosal cancer (p>0.05), and 100% in the node negative group and 90.0% in the node positive group (p>0.05). Conclusion: The survival rate of superficial esophageal cancer patient who was recieved operative resection was excellent. But, lymph node metastasis were found in superficial esophageal cancer, even in esophageal cancer limited to the muscularis mucosa. Systemic lymph node dissection which includes recurrent laryngeal nerve nodes and intraperitoneal nodes was recommended for favorable outcome in superficial esophageal cancer.

• Journal of Gastric Cancer
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• v.6 no.2
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• pp.109-113
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• 2006

Purpose: Various minimally invasive surgical techniques, such as an endoscopic mucosal resection and a laparoscopic gastrectomy, are becoming common practice for some cases of early gastric cancer (EGC) defined in terms of the depth of invasion being limited to the mucosa or submucosa. However, there are rare cases of early gastric cancer with massive lymph-node metastasis. Materials and Methods: From 6 university hospitals of Korea, 2,772 EGC cases were resected during the various period of analysis (1,432 cases of mucosal cancer and 1,340 of submucosal cancer). Results: As control data, we used the data from a single institute, CHA University Hospital. There were nine cases of early gastric cancer (9/2,772, 0.32%) with N3 lymph node metastasis defined by more than 15 lymph nodes being metastasized according to the UICC-TNM classification (pT1N3, stage IV). Two cases were mucosal cancer (2/1,432, 0.1 4%), and seven cases were submucosal cancer (7/1,340, 0.52%). Metastasized lymph nodes varied in number from 18 to 52. There were three male and six female patients with a mean age of 57. This is a totally reversed sex ratio compared to the usual gastric cancer or EGC. Among the total of 9 EGC patients, there were 5 who had superficial spreading carcinomas with surface areas larger than $25\;cm^2$. This is a significantly higher proportion compared to the general EGC population. When we compared the tumor size according to the LN status, the N3 group was definitely larger than the other groups. 78% of the pT1N3 cases showed lymphatic invasion, which is very high compared to the 4.7% in general EGC cases. Among the 9 cases, 6 patients had too short a follow-up period to evaluate the correct prognosis, but there was one patient with a non-curative resection and two patients with early recurrence. Although the sample size is small and the follow-up period is short, we can expect a very poor prognosis when we consider the common prognosis of EGC that is widely known and accepted. Conclusion: From these results, we can a conclude that the risk factors for pT1N3 gastric cancer are female patients, submucosal invasion, larger tumor size, and lymphatic invasion. However rare, the existence of pT1N3 gastric cancer needs to be taken into consideration, especially during the diagnosis. Furthermore, minimally invasive treatment for EGC needs to be chosen with great precaution. Since the prognosis of pT1N3 gastric cancer is expected to be poor, aggressive adjuvant chemotherapy may be necessary. (J Korean Gastric Cancer Assoc 2006;6:109-113)

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.177-185
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• 2009

Purpose: Preoperative clinical staging of gastric cancer is very important for determining the treatment plans and predicting the prognosis. The previous reports regarding the accuracy of computed tomography or endoscopic ultrasound for the preoperative staging of gastric cancer have shown various outcomes. We analyzed the diagnostic performance of CT and EUS, which are important staging tools for the staging of TN gastric cancer. Materials and Methods: We retrospectively analyzed 1,174 patients who underwent gastrectomy for gastric cancer at Seoul National University Bundang Hostpital from May, 2003 to December, 2007. We derived the Kappa value to examine the agreement of the preoperative staging obtained from CT and EUS with the pathological staging. Results: The mean age of the 1,174 patients was $59.31{\pm}11.98$ years. Six hundred thirty seven patients had early gastric cancer and 536 had advanced gastric cancer. The diagnostic performance between CT and EUS for the T staging showed no significant difference between CT and EUS for the kappa values. The kappa values showed moderate agreement at 0.4039 (P=0.021) and 0.4201 (P=0.026), respectively. This suggests that there is no difference between the two examinations for the overall T staging. Analysis of the discrimination of mucosal and submucosal lesions with EUS showed an accuracy of 58.92% and a Kappa value of 0.206 (P<0.001), suggesting fair agreement and a lower diagnostic performance than expected. To differentiate lesions with stages higher than or equal to T2 or T3 from the lesion with stages lower than T2 or T3, respectively, adoption of the higher stage from the CT staging or the EUS staging showed a larger AUC of 0.84 than that from either stage alone. The CT-derived node stage had the higher diagnostic performance (68.55%) than that of the EUS-derived node stage (60.82%) for the node staging. Conclusion: The CT-derived stage and EUS-derived stage showed comparable results for determining the T stage of gastric cancer. Yet the higher stage of the two stages from CT and EUS most accurately discriminated between those lesions with stages higher than T2 and those lesions with stages lower than T2.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.69-84
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• 1997

Background : Although the overall prognosis of patients with lung cancer is poor, highly effective treatment exists for the small subset of patients with early lung cancer(carcinoma in situ/micro- invasive cancer). But very few patients have benefit from them because these lesions are difficult to detect and localize with conventional white-light bronchoscopy. To overcome this problem, a Lung Imaging Fluorescence Endoscopic device(LIFE) was developed to detect and clearly delineate the exact location and extent of premalignant and early lung cancer lesions using differences in tissue autofluorescence. Purpose : The purpose of this study was to determine the difference of sensitivity and specificity in detecting dysplasia and carcinoma between fluorescence imaging and conventional white light bronchoscopy. Material and Methods : 35 patients (16 with abnormal chest X-ray, 2 with positive sputum study, 2 with undiagnosed pleural effusion, 15 with respiratory symptom) have been examined by LIFE imaging system. After a white light bronchoscopy, the patients were submitted to fluorescence bronchoscopy and the findings of both examinations have been classified in 3 categories(class I, II, III). From of all class n and III sites, 79 biopsy specimens have been collected for histologic examination: a comparison between histologic results and white light or fluorescence bronchoscopy has been performed for assessing sensitivity and specificity of the two methods. Results : 1) Total 79 sires in 35 patients were examined. Histology demonstrated 8 normal mucosa, 21 hyperplasia, 23 dysplasia, and 27 microinvasive and invasive carcinoma. 2) The sensitivity of white light or fluorescence bronchoscopy in detecting dysplasia was 60.9% and 82.6%, respectively. 3) The results of this study showed 70.3 % sensitivity for microinvasive or invasive carcinoma with LIFE system, versus 100% sensitivity for white light in 27 cases of carcinoma. The false negative study of LIFE system was 8 cases(3 adenocarcinoma and 5 small cell carcinoma), which were infiltrated in submucosal area and had normal epithelium. Conclusion : To improve the ability 10 diagnose and stage more accurately, fluorescence imaging may become an important adjunct to conventional bronchoscopic examination because of its high detection rate of premalignant and malignant epithelial lesion. But. it has limitation to detect in submucosal infiltrating carcinoma.

• Journal of Yeungnam Medical Science
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• v.22 no.1
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• pp.81-89
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• 2005

Background: Hysteroscopy is considered to be the gold standard not only for visualizing the cervical canal and the uterine cavity, but also for treating many different types of benign pathologies localized to those regions. The advent and evolution of endoscopic imaging and surgery during the last two decades has added new dimensions to the armamentarium of a gynecologist to combat intrauterine lesions. Office hysteroscopy is increasingly being used as a first line investigation for abnormal uterine bleeding and other diseases involving the uterine cavity. The aim of our study is to assess the diagnostic and operative efficacy of office hysteroscopy. Materials and Methods: In our department, 140 patients underwent a hysteroscopy examination and 18 of these underwent an office based hysteroscopy examination from September 1995 to March 2005. The cases who underwent an office based hysteroscopy examination were reviewed in order to assess the clinical usefulness and significance in the management of intrauterine lesions. Results: Major indication was abnormal uterine bleeding(12 cases, 66.7%). The others were a missed IUD and infertility. The hysteroscopic findings were a normal uterine cavity(6 cases, 33.3%), IUD in situ, polyp, submucosal myoma, endometrial hyperplasia and a placenta remnant. Conclusion: Office hysteroscopy is a safe, quick and effective method for making an intrauterine evaluation. In addition, it provides immediate results, offers the capacity of direct targeted biopsies of suspicious focal lesions, and offers the direct treatment of some intrauterine conditions.