• Radiation Oncology Journal
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• v.36 no.1
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• pp.71-78
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• 2018

Purpose: To compare the dose distribution of three-dimensional conformal radiation therapy (3DCRT) with intensity-modulated radiation therapy (IMRT) for post-mastectomy radiotherapy (PMRT) to left chest wall. Materials and Methods: One hundred and seven patients were randomised for PMRT in 3DCRT group (n = 64) and IMRT group (n = 43). All patients received 50 Gy in 25 fractions. Planning target volume (PTV) parameters-$D_{near-max}$ ($D_2$), $D_{near-min}$ ($D_{98}$), $D_{mean}$, $V_{95}$, and $V_{107}$-homogeneity index (HI), and conformity index (CI) were compared. The mean doses of lung and heart, percentage volume of ipsilateral lung receiving 5 Gy ($V_5$), 20 Gy ($V_{20}$), and 55 Gy ($V_{55}$) and that of heart receiving 5 Gy ($V_5$), 25 Gy ($V_{25}$), and 45 Gy ($V_{45}$) were extracted from dose-volume histograms and compared. Results: PTV parameters were comparable between the two groups. CI was significantly improved with IMRT (1.127 vs. 1.254, p < 0.001) but HI was similar (0.094 vs. 0.096, p = 0.83) compared to 3DCRT. IMRT in comparison to 3DCRT significantly reduced the high-dose volumes of lung ($V_{20}$, 22.09% vs. 30.16%; $V_{55}$, 5.16% vs. 10.27%; p < 0.001) and heart ($V_{25}$, 4.59% vs. 9.19%; $V_{45}$, 1.85% vs. 7.09%; p < 0.001); mean dose of lung and heart (11.39 vs. 14.22 Gy and 4.57 vs. 8.96 Gy, respectively; p < 0.001) but not the low-dose volume ($V_5$ lung, 61.48% vs. 51.05%; $V_5$ heart, 31.02% vs. 23.27%; p < 0.001). Conclusions: For left sided breast cancer, IMRT significantly improves the conformity of plan and reduce the mean dose and high-dose volumes of ipsilateral lung and heart compared to 3DCRT, but 3DCRT is superior in terms of low-dose volume.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1633-1636
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• 2015

Background: The advantages of Rapid Arc plans versus Intensity modulated radiotherapy plans for Carcinoma left breast were analyzed. Materials and Methods: In this study 20 Post mastectomy carcinoma left breast patients were analyzed. Both Intensity modulated Radiotherapy and Rapid Arc plans were generated for these patients. IMRT plans with 7 beams in an arc fashion and VMAT plans with two semi arcs were made to achieve 95% dose coverage to 100% volume. The plans were evaluated using Dose volume Histograms. Results: The mean Conformity and Homogeneity index in VMAT is found to be 1.05 and 0.065 respectively whereas in IMRT it was 1.07 and 0.069. The 20% volume of Heart received a mean dose of 960cGy in VMAT and 1300cGy in IMRT. The mean dose was 1236cGy in VMAT and 1870cGy in IMRT. The ipsilateral Lung received 3395cGy to 5% volume and 1840cGy to 20% volume on an average and the mean dose was 1205cGy in VMAT, while the same were found to be 3525cGy, 2012cGy and 1435cGy respectively in IMRT. The Contralateral Lung received a mean dose of 505cGy in VMAT and 553cGy in IMRT. The mean Monitor units in VMAT were 512MU and 1170MU in IMRT. The NTID in VMAT is $108.8{\times}10^5Gycm^3$ and $110.1{\times}10^5Gycm^3$ in IMRT. Conclusions: The target coverage, homogeneity and Conformity index were better in VMAT plans. The Ipsilateral Lung and heart dose were very less in VMAT plans. The Contralateral Lung dose and the Normal Tissue Integral Dose were also lesser in VMAT plans however the difference is not very appreciable. The MU in VMAT plans is almost 50% that of the IMRT plans which results in the reduction of treatment time. On the whole VMAT proves to be a better modality for treating Ca. Left Breast Patients.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.83-95
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• 2018

Purpose : After planning the Respiratory Gated Radiotherapy for Lung cancer, the movement and volume change of sparing normal structures nearby target are not often considered during dose evaluation. This study carried out 4-D dose evaluation which reflects the movement of normal structures at certain phase of Respiratory Gated Radiotherapy, by using Deformable Image Registration that is well used for Adaptive Radiotherapy. Moreover, the study discussed the need of analysis and established some recommendations, regarding the normal structures's movement and volume change due to Patient's breathing pattern during evaluation of treatment plans. Materials and methods : The subjects were taken from 10 lung cancer patients who received Respiratory Gated Radiotherapy. Using Eclipse(Ver 13.6 Varian, USA), the structures seen in the top phase of CT image was equally set via Propagation or Segmentation Wizard menu, and the structure's movement and volume were analyzed by Center-to Center method. Also, image from each phase and the dose distribution were deformed into top phase CT image, for 4-dimensional dose evaluation, via VELOCITY Program. Also, Using $QUASAR^{TM}$ Phantom(Modus Medical Devices) and $GAFCHROMIC^{TM}$ EBT3 Film(Ashland, USA), verification carried out 4-D dose distribution for 4-D gamma pass rate. Result : The movement of the Inspiration and expiration phase was the most significant in axial direction of right lung, as $0.989{\pm}0.34cm$, and was the least significant in lateral direction of spinal cord, as -0.001 cm. The volume of right lung showed the greatest rate of change as 33.5 %. The maximal and minimal difference in PTV Conformity Index and Homogeneity Index between 3-dimensional dose evaluation and 4-dimensional dose evaluation, was 0.076, 0.021 and 0.011, 0.0 respectfully. The difference of 0.0045~2.76 % was determined in normal structures, using 4-D dose evaluation. 4-D gamma pass rate of every patients passed reference of 95 % gamma pass rate. Conclusion : PTV Conformity Index was more significant in all patients using 4-D dose evaluation, but no significant difference was observed between two dose evaluations for Homogeneity Index. 4-D dose distribution was shown more homogeneous dose compared to 3D dose distribution, by considering the movement from breathing which helps to fill out the PTV margin area. There was difference of 0.004~2.76 % in 4D evaluation of normal structure, and there was significant difference between two evaluation methods in all normal structures, except spinal cord. This study shows that normal structures could be underestimated by 3-D dose evaluation. Therefore, 4-D dose evaluation with Deformable Image Registration will be considered when the dose change is expected in normal structures due to patient's breathing pattern. 4-D dose evaluation with Deformable Image Registration is considered to be a more realistic dose evaluation method by reflecting the movement of normal structures from patient's breathing pattern.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6346-6352
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• 2013

Radiotherapy of rectal cancer requires a stabilized image but the movement of patients is almost unavoidable in radiotherapy. In this study, the setup error using the radiation treatment technique was compared according to the loading time and BMI(Body Mass Index) for 14 patients with rectal cancer. In addition, the variation of the dose by the average setup error was compared. Therefore, the technique of a selective standard was established. As a result, 3DCRT(3-Dimensional Radiation Therapy) and VMAT(Volumetric Modulated Arc Therapy) showed a similar time and error. In comparison, IMRT(Intensity Modulated Radiation Therapy) increased the time two fold and the error four fold. In BMI, a more pyknic patient showed a larger error for all techniques. Regarding the dose, IMRT and VMAT increased much more than 3DCRT in the average error at the small bowel. Therefore, 3DCRT of the short time will be applied to pyknic rectal cancer. Moreover, VMAT selects than IMRT in the overexposure of the small bowel.

• Radiation Oncology Journal
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• v.30 no.3
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• pp.146-151
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• 2012

Purpose: This treatment planning study was undertaken to evaluate the impact of beam angle configuration of intensity-modulated radiotherapy (IMRT) on the dose of the normal liver in hepatocellular carcinoma (HCC). Materials and Methods: The computed tomography datasets of 25 patients treated with IMRT for HCC were selected. Two IMRT plans using five beams were made in each patient; beams with equidistance of $72^{\circ}$ (Plan I), and beams with a $30^{\circ}$ angle of separation entering the body near the tumor (Plan II). Both plans were generated using the same constraints in each patient. Conformity index (CI), homogeneity index (HI), gamma index, mean dose of the normal liver (Dmean_NL), Dmean_NL difference between the two plans, and percentage normal liver volumes receiving at least 10, 20, and 30 Gy (V10, V20, and V30) were evaluated and compared. Results: Dmean_NL, V10, and V20 were significantly better for Plan II. The Dmean_NL was significantly lower for peripheral (p = 0.001) and central tumors (p = 0.034). Dmean_NL differences between the two plans increased in proportion to gross tumor volume to normal liver volume ratios (p = 0.002). CI, HI, and gamma indices were not significantly different for the two plans. Conclusion: The IMRT plan based on beams with narrow separations reduced the irradiated dose of the normal liver, which would allow radiation dose escalation for HCC.

• Radiation Oncology Journal
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• v.38 no.2
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• pp.138-147
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• 2020

Purpose: To evaluate the dosimetric variations in patients of head and neck cancer treated with definitive or adjuvant radiotherapy using optimized non-coplanar (ncVMAT) beams with coplanar (cVMAT) beams using volumetric arc therapy. Materials and Methods: Twenty-two patients of head and neck cancer that had received radiotherapy using VMAT in our department were retrospectively analyzed. Each of the patients was planned using coplanar and non-coplanar orientations using an optimized couch angle and fluences. We analyzed the Conformity Index (C_IRTOG), Dose Homogeneity Index (DHI), Heterogeneity Index (HI_RTOG), low dose volume, target and organs-at-risk coverage in both the plans without changing planning optimization parameters. Results: The prescription dose ranged from 60 Gy to 70 Gy. Using ncVMAT, C_IRTOG, DHI and HI_RTOG, and tumor coverage (ID_95%) had improved, low dose spillage volume in the body V_5Gy was increased and V_10Gy was reduced. Integral dose and intensity-modulated radiation therapy factor had increased in ncVMAT. In the case of non-coplanar beam arrangements, maximum dose (D_max) of right and left humeral head were reduced significantly whereas apex of the right and left lung mean dose were increased. Conclusion: The use of ncVMAT produced better target coverage and sparing of the shoulder and soft tissue of the neck as well as the critical organ compared with the cVMAT in patients of head and neck malignancy.

• Progress in Medical Physics
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• v.26 no.4
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• pp.234-240
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• 2015

The purpose of this study is to analyze dosimetric parameters of patient with large and pendulous breast receiving breast radiotherapy in the prone versus supine position. The patient underwent computed tomography simulation in both prone and supine position. The homogeneity index (HI), conformity index (CI), coverage index (CVI) to the left breast as planning target volume (PTV) and the doses to the lung, heart, and right breast as organ at risk (OAR) were compared by using dose-volume histogram. The lifetime attributable risk (LAR) according to the prone and supine position was measured for the lung and right breast. The HI, CI of the PTV decreased 21.7%, 6.49%, respectively and the CVI increased 10.8% with the prone position. The mean and maximum dose to the left lung decreased 91.6%, 87.0%, respectively and the volume parameters also decreased over 99% with the prone position. The parameters to the right lung were same regardless of the position. The mean and maximum dose to the heart decreased 51.6%, 14.2% with the prone position. But the mean and maximum dose to the right breast increased unlike the other OARs. The LARs to the lung decreased 80.3% (left), 24.2% (right) but the LAR to the right breast doubled with the prone position. The prone position is a favorable alternative for irradiation of breast in patients with large and pendulous breasts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.744-754
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• 2017

In this study, an analytic hierarchy process (AHP) was conducted with the aim of developing a post-disaster refugee housing performance index system (PPS) to improve the post-disaster refugee housing (PRH) performance criteria for the foundation of quality-based development. The PRH was defined as a mid-term temporary housing facility that is used for a certain period before the permanent housing is established. The safety, rapidity, reusability, habitability, and economy were derived from major performance factors through prior research. A hierarchical PPS was organized by linking the major performance factors with the whole life cycle process of PRH. The priority of each performance index of PPS was determined quantitatively using the analytic hierarchy process through an expert survey. Based on AHP analysis, the performance criterion of the total weight 1-10 ranking and the performance criterion of the first rank in each category were classified into the essential performance criterion (must be achieved) and the others were classified into the recommended performance criterion (optional achieved) and the performance index was constructed considering all stages of PRH development. With the completion of the PRH performance index, it is expected that victims will be able to secure stable residence and return to their daily lives quickly.

• Journal of Distribution Science
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• v.14 no.6
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• pp.107-118
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• 2016

Purpose - Over 90% of Domestic logistics industry is small enterprise and they are experiencing growth stagnation due to price-based competition structure rather than constructing logistics service of high added value. In order to get over this situation and pursue the development of logistics industry, strengthening its competitiveness, through inter-enterprise cooperative network build-up, would be a key alternative. Therefore, in this study, an index for measuring inter-enterprise cooperation level of Joint logistics business will be developed as a typical collaborative business model in logistics industry. Moreover, a strengthening competitiveness method suggests a developmental step and a key management index to mature in logistics industry. Research Design, Data, Methodology - This study is an index development research for measuring inter-enterprise cooperation level of logistics industry. Such a level was measured by performing a survey by targeting enterprises that participated in Joint logistics business. The targeting enterprises are typical cooperative models in logistics industry. Measurement items were developed which were based on the presented items in existing research. Question items were composed of selection type questions as answering Yes/No. They measures implementation status of corporate activity and detailed activity items measuring qualitative level. Total samples were based on 116 enterprise samples including 90 logistics enterprises and 26 shippers. In addition, by evaluating the importance for Joint logistics business recognition with personnel working level, the weight of measuring variable was extracted. This study has built an assessment tools (LPCI) on Joint logistics business cooperation level in a situation where there are no previous studies on joint logistics business, this study is meaningful for other studies. Results - As a result of analyzing LPCI presented in this study, the score of logistics enterprise was represented as 59.9 points based on full score of 100 points and that of shippers as 47.2 points and cooperation level among enterprises participated in Joint logistics business was revealed to be very low. In particular, as a result of measuring the importance between logistics enterprise and shippers, the difference by each measurement standard was represented among those enterprises. This difference is considered to be a key factor that cooperative operational conformity between logistics enterprises and shippers is represented to be low. Conclusions - As most joint logistics business, being promoted at present, is sharing facility and information with joint logistics business, it is hard to find such a joint logistics business in reality based on cooperative business model in main cooperation agents. Therefore, competitiveness of logistics industry could be strengthened by promoting joint logistics business based on their mutual cooperation among enterprises. In other words, it is to secure sustainable competitiveness of joint logistics business together with creation of new market by inter-enterprise cooperation based on integration of basic logistics business.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.2
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• pp.107-115
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• 2007

Objective: A quality management system of international standardization organization (ISO) 9001:2000 has been proposed to properly evaluate and improve the quality of productions and services. The purpose of this article was to describe on successful introduction and application of the ISO system to human assisted reproductive technology (ART) center. Methods: Center for reproductive medicine and infertility of Cheil General Hospital started the action for ISO 9001:2000 certification at January-2004. The ISO system of our center was monitored by measuring the customer satisfaction index and periodical internal and external audit. Reports of non-conformity described corrective and preventive actions for problems and occurrences that were not consistent with the standard process and operation of our center. Continuous management and improvement were performed on the project of customer dissatisfaction. Results: Our center has got the certification of ISO 9001:2000 for "Research and development of IVF-ET program for infertility treatment" from Korean Foundation for Quality at June-2004. The policy of ISO was "To establish the best center of reproductive medicine and infertility" and "To establish the best quality management system". We found 140 cases and 7 cases of non-conformity in internal and external audit for three years, respectively, and performed corrective action. Conclusion: Improvement of customer satisfaction, systemic documentation and transparency and efficacy of working procedure were achieved by application and operation of the ISO system to our center. This ISO system could be used as a basic institutional management system for the national guideline to the human ART center.