• Radiation Oncology Journal
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• v.18 no.2
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• pp.150-156
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• 2000

Purpose : Stereotactic radiation therapy (SRT) can deliver highly focused radiation to a small and spherical target lesion with very high degree of mechanical accuracy. For non-spherical and large lesions, however, inclusion of the neighboring normal structures within the high dose radiation volume is inevitable in SRT This is to report the beam shaping using the partial closure of the independent jaw in SRT and the verification of dose calculation and the dose display using a home-made soft ware. Materials and Methods : Authors adopted the idea to partially close one or more independent collimator jaw(5) in addition to the circular collimator cones to shield the neighboring normal structures while keeping the target lesion within the radiation beam field at all angles along the arc trajectory. The output factors (OF's) and the tissue-maximum ratios (TMR's) were measured using the micro ion chamber in the water phantom dosimetry system, and were compared with the theoretical calculations. A film dosimetry procedure was peformed to obtain the depth dose profiles at 5 cm, and they were also compared with the theoretical calculations, where the radiation dose would depend on the actual area of irradiation. Authors incorporated this algorithm into the home-made SRT software for the isodose calculation and display, and was tried on an example case with single brain metastasis. The dose-volume histograms (DVH's) of the planning target volume (PTV) and the normal brain derived by the control plan were reciprocally compared with those derived by the plan using the same arc arrangement plus the independent collimator jaw closure. Results : When using 5.0 cm diameter collimator, the measurements of the OF's and the TMR's with one independent jaw set at 30 mm (unblocked), 15.5 mm, 8.6 mm, and 0 mm from th central beam axis showed good correlation to the theoretical calculation within 0.5% and 0.3% error range. The dose profiles at 5 cm depth obtained by the film dosimetry also showed very good correlation to the theoretical calculations. The isodose profiles obtained on the home-made software demonstrated a slightly more conformal dose distribution around the target lesion by using the independent jaw closure, where the DVH's of the PTV were almost equivalent on the two plans, while the DVH's for the normal brain showed that less volume of the normal brain receiving high radiation dose by using this modification than the control plan employing the circular collimator cone only. Conclusions : With the beam shaping modification using the independent jaw closure, authors have realized wider clinical application of SRT with more conformal dose planning. Authors believe that SRT, with beam shaping ideas and efforts, should no longer be limited to the small spherical lesions, but be more widely applied to rather irregularly shaped tumors in the intracranial and the head and neck regions.

• Journal of Chest Surgery
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• v.33 no.9
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• pp.697-706
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• 2000

Background: Isolated lung perfusion(ILP) was developed as a new treatment approach to non-resectable primary or metastatic lung cancer, because of its ability to reduce systemic toxicity while delivering high-dose chemotherapeutic agents to the target organs. This research was planned to evaluate the direct toxic effect of high-dose cisplatin to the lung tissue during isolated lung perfusion. Material and Method: Fifteen mongrel dogs were divided in the perfusate for 40 minutes. The second group was composed of 5 mongrel dogs which underwent ILP with cisplatin 2.5 mg/Kg added to the perfusate for 30 minutes and 10 minutes with washing solution without cisplatin. The third group underwent the same procedure as the second group except cisplatin 5.0 mg/Kg in the perfusate. Activities of serum angiotensin converting enzyme(ACE), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and concentration of serum lactate dehydrogenase(LDH) and blood urea nitrogen/creatinine (BUN/Cr) were analyzed in each groups at the time of pre-perfusion, 1 hour, 1 day, 1 week, and 2 weeks after ILP. Result: Serum ACE activities before and 1 hour, 1 day, 1 week, and 2 weeks after ILP in control group were 45.1$\pm$6.3, 44.6$\pm$9.3, 46.7$\pm$9.5, 50.8$\pm$9.1, 46.1$\pm$4.3 U/L. Those in cisplatin 2.5 and 5.0 mg/Kg groups were 49.4$\pm$12.6, 39.0$\pm$8.6, 42.3$\pm$15.9, 50.0$\pm$2.6, 53.8$\pm$8.3 and 55.5$\pm$12.3, 47.0$\pm$6.3, 45.1$\pm$6.9, 74.8$\pm$19.5, 60.2$\pm$12.0 U/L, respectively. Serum TNF-$\alpha$ activities in each group before and after ILP were 5.0$\pm$1.5 / 7.7$\pm$2.2 / 6.6$\pm$2.5 / 4.3$\pm$1.3 / 5.2$\pm$1.1(control), 8.7$\pm$1.6 / 9.9$\pm$2.2 / 7.9$\pm$1.5 / 6.3$\pm$2.2 / 7.4$\pm$2.4 (cisplatin 2.5 mg/Kg), and 6.9$\pm$0.7 / 8.9$\pm$3.4 / 7.9$\pm$4.0 / 3.3$\pm$0.9 / 5.8$\pm$1.3 pg/ml(cisplatin 5.0 mg/Kg). Mean LDH levels of each group were 225.7 / 271.3 / 328.9 / 350.8 / 255.7(control), 235.7 / 265.7 / 336.0 / 379.5 / 299.2 (cisplatin 2.5 mg/Kg), and 259.6 / 285.2 / 340.6 / 433.4 / 292.4 IU/L(cisplatin 5.0 mg/Kg). So there was no significant difference in serum ACE, TNF-$\alpha$, and LDH activity changes after ILP between the 3 groups. And, there was no significant changes in BUN/Cr in each groups, which was independent of ILP and perfused concentration of cisplatin. In addition, all dogs survived the ILP and there was no significant evidence of pulmonary vascular injury after 2 weeks of ILP with cisplatin. Conclusion: There was no harmful effect of cisplatin to the lund tissue of the mongrel dog up to 5.0 mg/Kg in perfusate. Therefore, it is perceived to be safe and effective to deliver high-dose cisplatin to the lung without pulmonary toxicity and renal damage with ILP.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.387-395
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• 1993

To identify pretreatment prognostic factors in carcinoma of the uterine cervix, a retrospective analysis was undertaken of 510 patients treated with curative radiation therapy in Seoul National University Hospital during the 7 year period, from March 1979 through December 1986. According to FIGO classification,35 patients were stage I B,89 were stage IIA, 232 were stage IIB,8 were stage IIIA, 134 were IIIB, and 12 were stage IVA. Five year locoregional control (LRC) rates in stage I B, II A, II B, IIIA, IIIB, and IVA were $79\%,78\%,70\%,58\%,51\%\;and\;27\%,$ respectively. Five year disease free survival (DFS) rates were $76\%,67\%,60\$,57\%,40\%,\;and\;25\%,$ respectively. Overall survival (OS) rates at five years were $82\%,72\%,67\%,67\%,51\%,\;and\;33\%,$ respectively. In univariate analyses, stage, age, initial hemoglobin level, type of histology, tumor size, and several CT findings including pelvic lymph node (LN) status, paraaortic lymph node (PAN) status, extent of parametrial invasion, bladder invasion, and rectal invasion were significant factors in terms of LRC. All these factors and elevation of BUN or creatinine were associated with DFS. In terms of overall survival, stage, initial hemoglobin level, type of histology, tumor size, elevation of BUN or creatinine, and five CT findings associated with LRC were prognostically significant. In multivariate analysis excluding CT findings, stage IV disease, non-squamous histology, and tumor size $\ge$4 cm were associated with poor LRC and DFS. Stage IV disease and tumor size significantly affected OS. in multivariate analysis including CT findings, histology, tumor size, and pelvic LN status on CT were uniformly significant in terms of LRC, DFS, and 05, PAN status on CT affected overall survival only.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.309-322
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• 2018

Naturally occurring asbestos (NOA) occurs in rocks and soils as a result of natural weathering and human activities. It is proved that inhalation of asbestos fibers can lead to increase risk of developing several diseases such as lung cancer and malignant mesothelioma. The parent rocks of asbestos have been mainly associated with (ultra)mafic and carbonate rock. The previous studies on NOA were mainly limited to (ultra)mafic rock-hosted asbestos, but studies on carbonate rock-hosted asbestos are relatively rare in S. Korea. Therefore, this study was aimed to examine mineralogical characteristics of carbonate rock-hosted NOA at three sites including Muju and Jangsu, Jeonbuk province and Asan, Chungnam province. Types of rocks at the three sites mainly consisted of Precambrian metasedimentary rocks, carbonate rock, and Cretaceous and Jurassic granites. Asbestos-containing carbonate rock samples were obtained for mineralogical characterization. XRD, PLM, EPMA, SEM and EDS analyses were used to characterize mineralogical characteristics of the carbonate rock-hosted NOA. From the carbonate rock, fibrous minerals were occurred acicular and columnar forms in the three sites. Fibrous minerals were composed of mainly tremolite and associated minerals included possibly asbestos containing materials (ACM) such as talc, vermiculite, and sepiolite. The length and aspect ratios of tremolite were similar to the standard asbestiform (length >$5{\mu}m$, length:width = 3:1). These results indicate that both non-asbestiform and asbestiform tremolite with acicular forms occurred in carbonate rocks at three sites. Geological and geochemical characteristics and mineral assemblages indicate tremolite and associated minerals might be formed by hydrothermal alternation and/or hydrothermal veins of carbonate rocks due to intrusion of acidic igneous rocks.

• Health Policy and Management
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• v.12 no.3
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• pp.1-22
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• 2002

Health is a fundamental human right and a sine qua non for happiness of people and for national development. Government has a responsibility for the provision of health services for their people. Recent changes of disease pattern, i.e. decrease of Infectious diseases and increase of chronic and degenerative diseases Including cancer and cardiovascular diseases, together with universal coverage of health insurance and improved living standard have prompted medical care utilization and skyrocketed the national health expenses. The goal of national health policy is improving the quality of life through the betterment of health level. To achieve this goal it is necessary to establish a healthcare system for lifetime, to improve the efficiency of healthcare delivery system, and to strengthen the public health services for disease prevention and health promotion. The current public health service programs are Inefficient due to an inconsistent policy for health service program, lack of health information system, irrational health program planning and evaluation, and Inadequate training of health workers. Local government has a legal responsibility for health service program planning and promoting the competence of health workers. Thus, municipal and provincial health departments should expand their roles and strengthen their function. The strategies for developing public health service programs at local level are ${\circled}1$ stipulating the goals of health policy, ${\circled}2$ promoting the ability for health program planning and evaluation, ${\circled}3$ establishing health information and surveillance system, ${\circled}4$ training of health workers, ${\circled}5$ establishing an institution for health information management and training of health workers, and ${\circled}61$ collaboration with local universities.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.227-235
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• 1997

Cytogenetic studies were performed in peripheral blood lymphocytes from hospital workers occupationally exposed to low doses of radiation (0.30 - 40.07mSv). The workers were divided into three groups according to their job area : 18 diagnostic radiology, 17 therapeutic radiology, and 16 nuclear medicine. The control group consisted of 49 non-radiation workers with no history of exposure to radiation. A higher percentage of cells with aberration(1.275%) was observed in the workers compared to the controls(0.677%) and the difference was statistically significant(p<0.001). The frequency of chromosomal aberration was $0.706{\times}10^{-2}$/cell in the exposed and $0.344{\times}10^{-2}$/cell in the control(p<0.05). Chromosomal exchange frequency was $0.083{\times}10^{-2}$/cell in the control vs $0.245{\times}10^{-2}$/cell in the workers. There was no evidence of significant increase of chromosome aberration related to age or to the duration of employment. The frequency of chromosomal exchange in workers of nuclear medicine was $0.313{\times}10^{-2}$/cell, which was significantly higher than in the control($0.083{\times}10^{-2}$/cell) or other working groups: therapeutic radiology($0.265{\times}10^{-2}$/cell), and diagnostic radiology($0.167{\times}10^{-2}$/cell). No dose-effect relation was found between chromosome aberration and total cumulative doses, recent 5 yr, recent 2 yr cumulative dose. But in case of last 1 yr cumulative dose, dose-dependant increase was observed when controls were considered(p<0.05). The radiation dose which workers have received was much lower than the maximum permissible dose, but there was a significant difference in the frequency of chromosome aberration between occupationally exposed workers and control. So, it is clear that chromosome aberration is a quite sensitive indicator of radiation exposure and it can be detected at very low dose level of occupational exposure.

• Radiation Oncology Journal
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• v.22 no.1
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• pp.55-63
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• 2004

Purpose : To evaluate the reflection of tumor motion according to the planning CT scan time. Material and Methods : A model of N-shape, which moved aiong the longitudinal axis during the ventilation caused by a mechanical ventilator, was produced. The model was scanned by planning CT, while setting the relative CT scan time (T: CT scan time/ventilatory period) to 0.33, 0.50, 0.67, 0.75, 1.00, 1.337, and 1.537. In addition, three patients with non-small cell lung cancer who received stereotactic radiosurgery In the Department of Radiation Oncology, Asan Medical Center from 03/19/2002 to 05/21/2002 were scanned. Slow (10 Premier, Picker, scan time 2.0 seconds per slice) and fast CT scans (Lightspeed, GE Medical Systems, with a scan time of 0.8 second per slice) were peformed for each patient. The magnitude of reflected movement of the N-shaped model was evaluated by measuring the transverse length, which reflected the movement of the declined bar of the model at each slice. For patients' scans, all CT data sets were registered using a stereotactic body frame scale with the gross tumor volumes delineated in one CT image set. The volume and three-dimensional diameter of the gross tumor volume were measured and analyzed between the slow and fast CT scans. Results : The reflection degree of longitudinal movement of the model increased in proportion to the relative CT scan times below 1.00 7, but remained constant above 1.00 T Assuming the mean value of scanned transverse lengths with CT scan time 1.00 T to be $100\%$, CT scans with scan times of 0.33, 0.50, 0.57, and 0.75 T missed the tumor motion by 30, 27, 20, and $7.0\%$ respectively, Slow (scan time 2.0 sec) and Fast (scan time 0.8 sec) CT scans of three patients with longitudinal movement of 3, 5, and 10 mm measured by fluoroscopy revealed the increases in the diameter along the longitudinal axis Increased by 6.3, 17, and $23\%$ in the slow CT scans. Conculsion : As the relative CT scan time increased, the reflection of the respiratory tumor movement on planning CT also Increased, but remained constant with relative CT scan times above 1.00 T When setting the planning CT scan time above one respiration period (>1.00 T), only the set-up margin is needed to delineate the planning target volume. Therefore, therapeutic ratio can be increased by reducing the radiation dose delivered to normal lung tissue.

• The Journal of Korean Society for Radiation Therapy
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• v.16 no.1
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• pp.57-65
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• 2004

Introduction : The phantom that includes high density materials such as steel was custom-made to fix lung and bone in order to evaluation inhomogeneity correction at the time of conducting radiation therapy to treat lung cancer. Using this, values resulting from the inhomogeneous correction algorithm are compared on the 2 and 3 dimensional radiation therapy planning systems. Moreover, change in dose calculation was evaluated according to inhomogeneous by comparing with the actual measurement. Materials and Methods : As for the image acquisition, inhomogeneous correction phantom(Pig's vertebra, steel(8.21g/cm3), cork(0.23 g/cm3)) that was custom-made and the CT(Volume zoom, Siemens, Germany) were used. As for the radiation therapy planning system, Marks Plan(2D) and XiO(CMS, USA, 3D) were used. To compare with the measurement value, linear accelerator(CL/1800, Varian, USA) and ion chamber were used. Image, obtained from the CT was used to obtain point dose and dose distribution from the region of interest (ROI) while on the radiation therapy planning device. After measurement was conducted under the same conditions, value on the treatment planning device and measured value were subjected to comparison and analysis. And difference between the resulting for the evaluation on the use (or non-use) of inhomogeneity correction algorithm, and diverse inhomogeneity correction algorithm that is included in the radiation therapy planning device was compared as well. Results : As result of comparing the results of measurement value on the region of interest within the inhomogeneity correction phantom and the value that resulted from the homogeneous and inhomogeneous correction, gained from the therapy planning device, margin of error of the measurement value and inhomogeneous correction value at the location 1 of the lung showed $0.8\%$ on 2D and $0.5\%$ on 3D. Margin of error of the measurement value and inhomogeneous correction value at the location 1 of the steel showed $12\%$ on 2D and $5\%$ on 3D, however, it is possible to see that the value that is not correction and the margin of error of the measurement value stand at $16\%$ and $14\%$, respectively. Moreover, values of the 3D showed lower margin of error compared to 2D. Conclusion : Revision according to the density of tissue must be executed during radiation therapy planning. To ensure a more accurate planning, use of 3D planning system is recommended more so than the 2D Planning system to ensure a more accurate revision on the therapy plan. Moreover, 3D Planning system needs to select and use the most accurate and appropriate inhomogeneous correction algorithm through actual measurement. In addition, comparison and analysis through TLD or film dosimetry are needed.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1470-1475
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• 1998

Two kinds of Korean rice-wine (Yakju) with different process and ingredients, and Japanese rice-wine (Sake) were chosen for this study, and throughly dried and solubilized in water or cell culture medium. In vitro cytotoxicity assays of the solubilized wine solids exhibited that maximum dilution factors for inhibition of B 16BL6 mouse melanoma cell growth were 16X for herbal medicine-added rice-wine (Korean rice-wine I) and typical Korean rice-wine (Korean rice-wine II), and 8X for Japanese rice-wine. Their cytotoxic effects on HRT18 human colon adenocarcinoma cells were even lower than those on B16BL6 cells. The morphology of the tumor cells were changed by addition of the solubilized wine solids. Inhibitory effect of the rice-wine on in vivo tumor growth and metastasis were monitored after implantation of B16BL6 cells into C57BL/6 mice with daily feeding the solubilized wine solids. Compared to non-fed control groups, B16BL6 tumor growth and metastasis to lung were clearly inhibited by feeding the wine solids, in order of Korean rice-wine I > Korean rice-wine II > Japanese rice-wine. The data of in vitro cytotoxicity and the cell shape changes indicate that the inhibitory effect of tumor progression may be attributed to tumor cell differentiation or immune stimulation induced by certain components in the rice-wine, rather than direct cytotoxicity of the components.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.57-63
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• 2010

Purpose: We performed an immunohistochemical study with pre-treatment biopsy specimens to evaluate the prognostic significance of four biomolecular markers which can be used as a predictive assay for radiotherapy (RT) treatment of nasopharyngeal carcinoma (NPC). Materials and Methods: From January 1998 through December 2006, 68 patients were histologically diagnosed as non-metastatic NPC and treated by RT. Only 38 patients had the paraffin block for the immunohistochemical study. Thirty-one patients had undifferentiated carcinoma and 7 patients had squamous cell carcinoma. Thirtytwo patients (84%) had advanced stage NPC (2002 AJCC Stage III~IV). Immunohistochemical staining was performed for Met, COX-2, nm23-H1, and epidermal growth factor receptor (EGFR) expression using routine methods. Results: The median follow-up time was 30 months (range, 11 to 83 months) for all patients, and 39 months (range, 19 to 83 months) for surviving patients. The 5-year overall survival (OS) rate of the patients with high Met extent (${\geq}50%$) was significantly lower than that of the patients with low Met extent (48% vs. 84%, p=0.02). In addition, Met extent was also a significant prognostic factor in multivariate analysis (p=0.01). No correlation was observed between Met extent and T stage, N stage, stage group, gender, age, and the response to chemotherapy or RT. Met extent showed moderate correlation with COX-2 expression (Pearson coefficient 0.496, p<0.01), but COX-2 expression did not affect OS. Neither nm23-H1 or EGFR expression was a prognostic factor for OS in this study. Conclusion: High Met extent (${\geq}50%$) might be an independent prognostic factor that predicts poor OS in NPC treated with RT.