• Journal of Biomedical Engineering Research
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• v.14 no.1
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• pp.17-22
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• 1993

Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided intro two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weights). The other group received no Photofrin E Mice from both groups were irradiated for approximately 15 minutes at 100,300, or $500{\;}mW/\textrm{cm}^2$ with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photofrin II increased surface temperature by at least 40% and the temperature rise due to $300{\;}mW/\textrm{cm}^2$ irradiation exceeded values for hyperthermia. Lights and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise.

• Journal of Multimedia Information System
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• v.5 no.1
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• pp.35-42
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• 2018

Direct volume rendering (DVR) is an important 3D visualization method for medical images as it depicts the full volumetric data. However, because DVR renders the whole volume, regions of interests (ROIs) such as a tumor that are embedded within the volume maybe occluded from view. Thus, conventional 2D cross-sectional views are still widely used, while the advantages of the DVR are often neglected. In this study, we propose a new visualization algorithm where we augment the 2D slice of interest (SOI) from an image volume with volumetric information derived from the DVR of the same volume. Our occlusion-based DVR augmentation for SOI (ODAS) uses the occlusion information derived from the voxels in front of the SOI to calculate a depth parameter that controls the amount of DVR visibility which is used to provide 3D spatial cues while not impairing the visibility of the SOI. We outline the capabilities of our ODAS and through a variety of computer tomography (CT) medical image examples, compare it to a conventional fusion of the SOI and the clipped DVR.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.222-224
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• 2002

In proton and heavy ion radiotherapy, compensators are required to modify the energy of heavy ion, to compensate the local difference of tumor depth. Conventional compensators have to be created, exchanged, and stored for each patient and for each irradiation directions. A Cylinder Type Liquid Variable Compensator is and is under development. Hexagonal cylinders will be arranged in honeycomb structure. In which air and fluid are divided by hexagonal pistons. The position of each piston will be changed in each cylinder for adjusting the thickness of fluid for variable compensator. The location of each hexagonal piston is determined by each controlling cylinder connected to the hexagonal cylinder by inlet pipes of fluid. Each controlling cylinder includes controlling a piston, which is moved mechanically. Each controlling cylinder is to be moved by a motor driven by a computer.

• Journal of Gastric Cancer
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• v.16 no.4
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• pp.254-259
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• 2016

Purpose: Owing to increased life expectancy, the number of elderly patients with gastric cancer has increased. This study aimed to identify the outcomes of gastric cancer patients aged 80 years or older through comparison of their clinicopathological characteristics, surgical outcomes, and oncologic outcomes. Materials and Methods: Between January 2006 and December 2013, the records of 478 patients who underwent surgery for gastric cancer were retrospectively evaluated. Patients were divided into two groups: patients <80 years old (n=446) and patients ${\geq}80$ years old (n=32). Results: There were no significant differences in sex, body mass index, length of hospital stay, duration of surgery, depth of invasion, nodal metastasis, histologic type, or tumor size between the two groups. However, significant differences were found for the American Society of Anesthesiologist score and the serum albumin level between the two groups. Postoperative morbidity, mortality, disease-free survival, and recurrence rate did not differ between curatively resected patients in the two groups. Conclusions: In elderly patients with gastric cancer, active treatment including radical gastrectomy is necessary.

• The Korean Journal of Cytopathology
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• v.5 no.2
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• pp.99-105
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• 1994

We studied cervical cytology of 175 cases of histologically confirmed microinvasive squamous cell carcinoma of the uterine cervix in Cheil General Hospital from 1991 to 1993. Excluding 32 cases of insufficient smear, 143 cases were reviewed in view of background, cellularity, smear pattern, nuclear chromatin and presence of nucleoli. The characteristic findings of microinvasive carcinoma were syncytia and/or individual tumor cells in the focally necrotic inflammatory background. Nuclear chromatin was clear or fine. Nucleoli were observed in 55%. The prediction rate of microinvasive carcinoma was 74%. There is no significant relationship between the cellular features and depth of invasion.

• Journal of Gastric Cancer
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• v.20 no.2
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• pp.212-224
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• 2020

Purpose: miR-205 is a tumor suppressor and plays an important role in tumor invasiveness. However, the role of miR-205 in human gastric cancer (GC) epithelial-mesenchymal transition (EMT) remains unclear. The aim of this study was to investigate the molecular mechanism of miR-205 in the regulation of EMT in GC invasion. Materials and Methods: Quantitative polymerase chain reaction (qPCR) was used to detect the expression of miR-205 in GC. Further, the correlation between the pathological parameters and prognosis of GC was statistically analyzed. A transwell model was used to evaluate the effect of miR-205-3p on the invasion and migration of GC cells. qPCR, western blotting, and luciferase assay were performed to analyze the relationship and target effects between miR-205-3p and the expression of zinc finger electron box binding homologous box 1 (ZEB1) and 2 (ZEB2). Results: We found that the levels of miR-205-3p were significantly lower (P<0.05) in GC tissues than in matched normal tissues. Additionally, the expression of miR-205-3p was related to the tumor invasion depth, lymph node metastasis, lymph node invasion, and tumor, node, metastasis stage. Patients with lower miR-205-3p expression levels in the tumors had a poorer prognosis. The in vitro assays indicated that miR-205-3p could affect the invasion ability and EMT of GC cells by targeting the expression of both ZEB1 and ZEB2. Conclusions: miR-205-3p promotes GC progression and affects the prognosis of patients by targeting both ZEB1 and ZEB2 to directly influence EMT.

• Journal of Gastric Cancer
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• v.4 no.3
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• pp.137-142
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• 2004

Purpose: There have been some controversies over the therapeutic principles of advanced gastric cancer, and the results of treatment have been variable, especially for stage III disease. This study was conducted to define the prognostic factors of stage III gastric cancer. Materials and Methods: This retrospective study was based on the medical records of 179 patients with stage III disease who received a gastrectomy from January 1990 to December 1994. The 5-year survival rate was analyzed according to the age, sex, tumor location, tumor size, Borrmann's type, depth of invasion, lymph-node metastasis, ratio of metastatic lymph nodes, type of surgical resection, extent of lymphnode dissection, curability of resection, postoperative chemotherapy, and pathological stage. The statistical analysis was done by using the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards model. Results: The overall 5-year survival rate was $61.6\%$ the 5-year survival rates according to subgroup were $69.7\%$ for stage IIIa ($100\%$ for $T_{2}N_{2}$, $70.0\%$ for $T_{3}N_{1}$, $68.6\%$ for $T_{4}N_{0}$), and $54.1\%$ for stage IIIb ($T_{3}N_{2}$) (P<0.05). Among various clinicopathologic factors of stage III gastric cancer, the age of the patient, the tumor location, the gross type of tumor, the type of gastric resection, the extent of lymph-node dissection, the curability of resection, and the subgroups of stage III were statistically significant in the univariate survival analysis. The multivariate analysis defined the curability of resection, the extent of lymph-node dissection, the type of operation, the stage of disease, and the age of the patient as independent prognostic factors. Conclusion: A curative surgical resection and an extended lymph-node dissection are thought to be most important for improving the survival rate in stage III gastric cancer patients.

• Journal of Gastric Cancer
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• v.13 no.2
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• pp.93-97
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• 2013

Purpose: Endoscopic submucosal dissection has recently been practiced on a differentiated type of early gastric cancer. However, there is no clear evidence for endoscopic treatments of signet ring cell carcinoma. The aim of this study is to identify the predictive clinicopathological factors for lymph node metastasis in signet ring cell carcinoma for assisting endoscopic submucosal dissection trials. Materials and Methods: A total of 186 patients with early signet ring cell carcinoma who underwent radical curative gastrectomy between January 2001 and September 2009 were enrolled in this study. Retrospective reviews of their medical records are being conducted. Several clinicopathologic factors were being investigated in order to identify predictive factors for lymph nodes metastasis: age, gender, tumor size, type of operation, tumor location, gross type, ulceration, Lauren's classification, depth of invasion, and lymphatic invasion. Results: The lymph node metastasis rate for signet ring cell carcinoma was 4.3% (n=8). Of the 186 lesions with early signet ring cell carcinoma, 91 (48.9%) tumors were larger than 15 mm in size and 40 (21.5%) showed submucosal invasions in the resection specimens. In multivariate analysis, only the lymphatic invasion (P<0.0001) showed an association with lymph node metastasis. To evaluate cutoff values for tumor sizes in the presence of lymph node metastasis, early signet ring cell carcinomas with lymphatic invasions were excluded. In the absence of lymphatic invasion, mucosal cancer with tumor sizes <15 mm had no lymph node metastasis. Conclusions: Endoscopic submucosal dissection can be performed on patients with early signet ring cell carcinoma limited to the mucosa and less than 15 mm.

• Journal of Gastric Cancer
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• v.6 no.4
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• pp.221-226
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• 2006

Purpose: Controversy still exists over in the prognostic significance of microscopic tumor cell dissemination in patients with cancer. This study evaluated the prognostic implication of isolated tumor cells in the bone marrow of patients with gastric cancer. Materials and Methods: Four hundred nineteen (419) patients who underwent surgery for gastric cancer between June 1998 and July 2000 were enrolled in the study. Bone marrow aspirate was obtained from the iliac crest before removal of the primary tumor. Mononuclear cells were isolated and stained with AE-1/AE-3 PAN-CYTOKERATIN. Results: Cytokeratin-positive cells were found in the bone marrow of 219 patients (52.3%). The incidence varied significantly with the depth of invasion (P=0.021) and the stage (P=0.026). The five-year survival rate of patients with cytokeratin-positive cells was 74.1% and that of patients without cytokeratin-positive cells was 81.1%(P=0.2481). There were no significant differences in the recurrence rate and the site of recurrence according to whether or not cytokeratin-positive cells were present in the bone marrow. Conclusion: The presence of cytokeratin-positive cells in the bone marrow of patients with gastric cancer did not predict outcome and recurrence. Therefore, it cannot be used as a prognostic factor.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.1
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• pp.26-34
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• 2009

Purpose: The purpose of this study was to find out what clinicopathologic or immunohistochemical parameter that may affect FDG uptake of primary tumor in PET/CT scan of the gastric carcinoma patient. Materials and Methods: Eighty-nine patients with stomach cancer who underwent pre-operative FDG PET/CT scans were included. In cases with perceptible FDG uptake in primary tumor, the maximum standardized uptake value (SUVmax) was calculated. The clinicopathologic results such as depth of invasion (T stage), tumor size, lymph node metastasis, tumor differentiation and Lauren's classification and immunohistochemical markers such as Ki-67 index, expression of p53, EGFR, Cathepsin D, c-erb-B2 and COX-2 were reviewed. Results: Nineteen out of 89 gastric carcinomas showed imperceptible FDG uptake on PET/CT images. In cases with perceptible FDG uptake in primary tumor, SUVmax was significantly higher in T2, T3 and T4 tumors than T1 tumors ($5.8{\pm}3.1$ vs. $3.7{\pm}2.1$, p=0.002). SUVmax of large tumors (above or equal to 3 cm) was also significantly higher than SUVmax of small ones (less than 3 cm) ($5.7{\pm}3.2$ vs. $3.7{\pm}2.0$, p=0.002). The intestinal types of gastric carcinomas according to Lauren showed higher FDG uptake compared to the non-intestinal types ($5.4{\pm}2.8$ vs. $3.7{\pm}1.3$, p=0.003). SUVmax between p53 positive group and negative group was significantly different ($6.0{\pm}2.8$ vs. $4.4{\pm}3.0$, p=0.035). No significant difference was found in presence of LN metastasis, tumor differentiation, Ki-67 index, and expression of EGFR, Cathepsin D, c-erb-B2 and COX-2. Conclusion: T stage of gastric carcinoma influenced the detectability of gastric cancer on FDG PET PET/CT scan. When gastric carcinoma was perceptible on PET/CT scan, T stage, size of primary tumor, Lauren's classification and p53 expression were related to degree of FDG uptake in primary tumor.