• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1164-1174
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• 2020

Purpose To evaluate a deep learning model to predict recurrence of thyroid tumor using preoperative ultrasonography (US). Materials and Methods We included representative images from 229 US-based patients (male:female = 42:187; mean age, 49.6 years) who had been diagnosed with thyroid cancer on preoperative US and subsequently underwent thyroid surgery. After selecting each representative transverse or longitudinal US image, we created a data set from the resulting database of 898 images after augmentation. The Python 2.7.6 and Keras 2.1.5 framework for neural networks were used for deep learning with a convolutional neural network. We compared the clinical and histological features between patients with and without recurrence. The predictive performance of the deep learning model between groups was evaluated using receiver operating characteristic (ROC) analysis, and the area under the ROC curve served as a summary of the prognostic performance of the deep learning model to predict recurrent thyroid cancer. Results Tumor recurrence was noted in 49 (21.4%) among the 229 patients. Tumor size and multifocality varied significantly between the groups with and without recurrence (p < 0.05). The overall mean area under the curve (AUC) value of the deep learning model for prediction of recurrent thyroid cancer was 0.9 ± 0.06. The mean AUC value was 0.87 ± 0.03 in macrocarcinoma and 0.79 ± 0.16 in microcarcinoma. Conclusion A deep learning model for analysis of US images of thyroid cancer showed the possibility of predicting recurrence of thyroid cancer.

• Korean Journal of Radiology
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• v.23 no.12
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• pp.1269-1280
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• 2022

Objective: This study aimed to evaluate the usefulness of quantitative indices obtained from deep learning analysis of gadoxetic acid-enhanced hepatobiliary phase (HBP) MRI and their longitudinal changes in predicting decompensation and death in patients with advanced chronic liver disease (ACLD). Materials and Methods: We included patients who underwent baseline and 1-year follow-up MRI from a prospective cohort that underwent gadoxetic acid-enhanced MRI for hepatocellular carcinoma surveillance between November 2011 and August 2012 at a tertiary medical center. Baseline liver condition was categorized as non-ACLD, compensated ACLD, and decompensated ACLD. The liver-to-spleen signal intensity ratio (LS-SIR) and liver-to-spleen volume ratio (LS-VR) were automatically measured on the HBP images using a deep learning algorithm, and their percentage changes at the 1-year follow-up (ΔLS-SIR and ΔLS-VR) were calculated. The associations of the MRI indices with hepatic decompensation and a composite endpoint of liver-related death or transplantation were evaluated using a competing risk analysis with multivariable Fine and Gray regression models, including baseline parameters alone and both baseline and follow-up parameters. Results: Our study included 280 patients (153 male; mean age ± standard deviation, 57 ± 7.95 years) with non-ACLD, compensated ACLD, and decompensated ACLD in 32, 186, and 62 patients, respectively. Patients were followed for 11-117 months (median, 104 months). In patients with compensated ACLD, baseline LS-SIR (sub-distribution hazard ratio [sHR], 0.81; p = 0.034) and LS-VR (sHR, 0.71; p = 0.01) were independently associated with hepatic decompensation. The ΔLS-VR (sHR, 0.54; p = 0.002) was predictive of hepatic decompensation after adjusting for baseline variables. ΔLS-VR was an independent predictor of liver-related death or transplantation in patients with compensated ACLD (sHR, 0.46; p = 0.026) and decompensated ACLD (sHR, 0.61; p = 0.023). Conclusion: MRI indices automatically derived from the deep learning analysis of gadoxetic acid-enhanced HBP MRI can be used as prognostic markers in patients with ACLD.

• Journal of The Korean Association For Science Education
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• v.28 no.5
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• pp.395-408
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• 2008

The purpose of this study was to analyze Korean Women's U.S. Ph.D. Degree-seeking Process and career development in the field of science and engineering in the United States. We conducted the analysis on the basis of SED (Survey of Earned Doctorates) data of the National Science Foundation. Since 2001, the number of Korean Ph.D. degree recipients from United States universities has been increasing and about 25% of them were women. Their median age was 33.3 years old, and one third of them were the recipients of research and teaching assistantships while pursuing a Ph.D. degree. At the time of receiving the degree, 51.8% reported having definite commitments for employment or postdoctoral study or research. Over 70% of the degree holders were presumed to stay and work in the United States. The study finally addressed policy implications regarding their recruitment to Korea and a need for a longitudinal survey.

• Journal of Korean Academy of Nursing
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• v.25 no.2
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• pp.372-389
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• 1995

The frequency with which administration of chemotherapy for gynecological cancer treatment is used has increased along with the use of surgery and radiotherapy Among the various side effects of chemotherapy, stomatitis causes a problem of function and sensation in the oral cavity. This oral discomfort can be categorized into two components ; perceived oral symptoms and observed oral symptoms. If the oral problem continues, it may cause infection, bleeding and nutritional deficiencies. As a result of this condition, compliance with the treatment process can be affected as well as the prognosis for the cancer patients. But as the oral discorrfort usually appears after chemotherapy, it is often not reported to the health care personnel as a patient problem. Without problem identification of the oral discomfort and ability to assess the problem, effective intervention cannot be planned. Therefore, this study was conducted to identify the pattern and the degree of oral discomfort due to cancer chemotherapy and thus to provide data for identification of the patient problem and for nursing assessment. The design of this study was a longitudinal de-scriptive study The subjects were in - patients who received chemotherapy under the diagnosis of gynecological cancer between Mar. 15, 1994 and May 15, 1994 at a general hospital in Seoul, Korea. The number of subjects was 64 and they were divided into two groups, one of 41 (A : 5FU & Neoplatin), the other of 23(B : Neoplatin, Cytoxan, Adriamycin), according to the treatment regimen. The data were collected for 24 days using self-re-port instruments. The instruments were the 「Perceived Oral Symptom Assessment Tool」 and 「Observed Oral Symptom Assessment Tool」 developed by this researcher. Data were analyzed using the SPSS-PC program, ANOVA, t-test, paired t-test and the Pearson Correlation Coefficient were applied. The results of this study are as follows : 1. In A regimen the peak time for perceived oral symptom scores was the fifth day after chemotherapy, and the tenth day for observed oral symptom scores. Both of the problems started on first day of chemotherapy and were not resolved completely until the 24th day after treatment. 2. In B regimen, the peak time for perceived oral symptom scores was on the seventh day after chemotherapy, and the eighth day for observed oral symptom scores. It was noted that perceived oral symptom scores were higher than observed oral symptom scores consistently for 24 days. Both also started on first day of chemotherapy, and were not resolved completely until the 24th day after chemotherapy. 3. There were no differences statistically in perceived oral symptom scores between A and B regimen. The loss of appetite and xerostomia caused the most severe discomfort in both of these two groups. 4. The were no differences statistically in observed oral symptom scores between the A and B regi moil. In the A regimen, the highest observed symptom scores were the lips, gingiva, tongue and buccal membrane in that order. But in the B regimen, the highest observed symptom scores were tongue, lips, buccal membrane and gingiva in that order. 5. In A regimen, the patients who had gingival edema and dentures had significantly higher perceived oral symptom scores. And those who had gingival edema and bleeding, foul odor and aphthous stomatitis had significantly higher observed oral symptom scores. 6. In B regimen, the patients who had the experience of stomatitis in the last course of chemotherapy had significantly higher perceived oral symptom scores. Those who had gingival edema had significantly higher observed oral symptom scores. 7. In the A regimen there was no correlation between lab values for lymphocytes and albumin with perceived oral symptom scores and observed oral symptom scores. In the B regimen, there was a significant negative correlation between lymphocytes and albumin with the observed oral symptom scores, but not between perceived oral symptom scores and lymphocytes and albumin values. In conclusion, the nurse should expect that the patient undergoing chemotherapy will complain severely about subjective discomfort and before objective physical change is observed. Also the patients who have chronic oral problems such as dentures, gingival edema and bleeding, foul odor, aphthous stomatitis will complain of severe oral discomfort due to chemotherapy.

• 한국벤처창업학회:학술대회논문집
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• 2006.04a
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• pp.167-201
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• 2006

Korean corporations are transforming their vertical operational structure to a team-based structure to compete in the rapidly changing environment and for improved performance. However, a high percentage of the respondents in KBS said that despite the appearance of the present team structure, the organization operates much like a vertically-structured organization. This result can be attributed to the lack of study and implementation toward the goal of empowerment, the key variable for the success of the team-based structure. This study aims to provide policy suggestions on how to implement the process of empowerment, by investigating the conditions that hinder the process and the attitude of the KBS employees. For the cross-sectional study, this thesis examined the domestic and international references, conducted a survey of KBS employees, personal interviews and made direct observations. Approximately 1,200 copies of the Questionnaire were distributed and 474 were completed and returned. The analysis used SPSS 12.0 software to process the data collected from 460 respondents. For the longitudinal-study, six categories that were common to this study and "The Report of the Findings of KBS Employees' View of the Team Structure" were selected. The comparative study analyzed the changes in a ten-month period. The survey findings showed a decrease of 24.2%p in the number of responses expressing negative views of the team structure and a decrease of 1.29%p in the number of positive responses. The findings indicated a positive transformation illustrating employees' improved understanding and approval of the team structure. However, KBS must address the issue on an ongoing basis. It has been proven that the employee empowerment increases the productivity of the individual and the group. In order to boost the level of empowerment, the management must exercise new, innovative leadership and build trust between the managers and the employees first. Additional workload as a result of shirking at work places was prevalent throughout all divisions and ranks, according to the survey data. This outcome leads to the conclusion that the workload is not evenly distributed or shared. And the data also showed the employees do not trust the assessment and rewards system. More attention and consideration must be paid to the team size and job allocation in order to address this matter; the present assessment and rewards system need to be complemented. The type of leadership varies depending on the characteristics of the organization's structure and employees' disposition. KBS must develop and reform its own management, leadership style to suit the characteristics of individual teams. Finally, for a soft-landing of KBS team structure, in-house training and education are necessary.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.971-976
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• 2008

Purpose : Surveillance for detecting and managing latent tuberculosis infection (LTBI) is a key component of tuberculosis control. The classic surveillance tool, the tuberculin skin test (TST), may have some limitations when used in the Bacillus Calmette-$Gu{\acute{e}}rin$ (BCG)-vaccinated population. The object was to perform a blood test $QuantiFERON^{(R)}$-TB Gold In Tube (QFT-G IT) based on the detection of interferon-$\gamma$ ($IFN-{\gamma}$) released by T cells in response to Mycobacterium tuberculosis-specific antigens, and to compare the efficacy of this new diagnostic tool for LTBI with that of TST. Methods : For six months, between October 1, 2006 and April 30, 2007, data were collected from 111 patients under 15 years of age at Severance Children's Hospital. TST and QFT-G IT tests were performed with children with or without contact histories of tuberculosis. In addition to these tests, we examined comparative data from 29 adults who had tuberculosis, to detect false negative rates in the QFT-G IT method. Results : Thirty-three children had household contact histories. In this group, 15% and 42% of cases were found to be positive using the QFT-G IT assay and TST, respectively. Agreement was low between these two tests (${\kappa}=0.39$). In the adult active tuberculosis group, the QFT-G IT false negative rate defined as a positive culture and a negative QFT-G IT result was 12.5%. Conclusion : In diagnosing LTBI in children, the usefulness of a whole-blood $IFN-{\gamma}$ assay employing TB-specific antigens will be revealed only by examining additional longitudinal clinical data; this study serves as a starting point in that process.

• Child Health Nursing Research
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• v.2 no.2
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• pp.45-57
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• 1996

A serious disease in a family influences the entire family member given the fact that the members closely interact with each other. Especially in terms of pediatric nursing, study on family gains importance as the need to care of families whose children with developmental disabilities and chronic disease This study was done based on The Resiliency Model of Family Adjustment and Adaptation(McCubbin, 1991) is intended to examine the stress of parents whose children suffer from cleft lip or /and cleft palate. It also helps them to cope with the stress and analyze the relationship between the stress and coping This study used Family Inventory of Life Events and Changes (FILE) and Coping Health Inventory for Parents(CHIP) for measuring family stress and coping. The two instruments are revised to fit the social and cultural environment of Korean culture. Data collection was done from April 18, 1996 to May 18, 1996 at 8 University medical centers located in Seoul. Those who answered questionnaires were 84 parents whose children have cleft lip or /and cleft palate. SPSS PC+ was used to analyze the data collotted. Programs used for data analysis were t-test, ANOVA, Pearson correlation coefficient. The study is summarized as follows .1. The average score of family stress is 10.46(percentage of the full score 24.90) and 'finance and business strains'(3.25), and 'intrafamily strains'(2.65) ranked the highest. The average score of family's coping is 1.93, which is close to the answer of' moderately helpful' and they are measured to put their utmost efforts to' intergration and cooperation of family and optimistic definition on the situation'. 2. There is no significant statistical correlation between the family stress and coping. 3. Mothers show more stress than fathers in the parts of 'illness and family care strains' and 'losses'(t〓-2.34, t〓-2.32, p<.05). 4. Fathers show more willingness to cope with the stress than mothers do in the parts of' seeking social support','self-esteem','emotional comfort' 5. Mothers are more stress than fathers in the parts of family stress and its coping with it by usual traits(t〓-2.78, p<.05). Parents with religion are measured to cope more willingly than those who are not 6. Income of a family shows positive correlationship with family coping (r〓.28, p<.05). The study shows that gender difference is significant variable in studying on family stress and coping. Mothers get more stress than fathers, which has much to do with the fact that they are in charge of raising children and keeping houseworks. Accordingly, managing family crisis and its survival can be induced by giving support for the mothers, studying fathers including the rest of the family members and giving nursing care and arbitration ; religious background is also considered to be one of the important factors in family stress , judging from the relationship between family income and family's coping, caring given to suffering children is needed on societal levels. The above considerations bring up the need to have a longitudinal study of children with congenital anomaly including cleft lip or /and cleft palate and their families about family stress and coping. Resiliency programs on family system and their effectiveness and the relationship between the enlarged families with social and cultural values reflecting Korean tradition are also needed to be studied.

• Women's Health Nursing
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• v.4 no.1
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• pp.5-35
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• 1998

This study attempted to determine the relation between the maternal role strain and their husbands' support in employed and nonemployed first-time mothers, and how it changed over time. A descriptive, longitudinal and comparative study design was conducted to collect and analyzed the data at three times(at 3-4days, at 4-6wks and at 3-month postpartum) regarding the change of maternal role strain and their husbands' support in employed and nonemployed first-time mothers. The subjects were 133 first-time mothers who delivered vaginally at K university hospital in Deagu, Korea from Dec., 1994 to Oct., 1995. Among these 58 were employed and 75 were nonemployed first-time mothers. This instruments used to data collection in this study were by Hobbs(1968 : The Difficulty Index for First-time Parents), Staffensmeier(1982: Transition Difficulty Measure), Tayer(1976: Emotional Support from Husband), Lee, Hae Kyoung(1992 : Physical Support from Husband). The analysis of data was done with SAS/PC program which included percentage, $x^2$-test, Pearson correlation, Repeated Measure ANOVA, Time Contrast Analysis and t-test. The results were as follows : 1. There was a significant negative correlation only at 3-4days(r=-.19, P=.0265) and at 4-6wks postpartum(r=-.18, P=.0392) between maternal role strain and husband's support of the first-time mothers. Thus, the more support from husband, the less maternal role strains the first-time mothers felt. Therefore, the 1st hypothesis that "the more husband's support the first-time mother felt at all the time of testing, the less maternal role strains they got" was partially supported at 3-days and 4-6 weeks postpartum. There was no correlation between maternal role strain and t husband's support of the employed first-time mothers at al testing times(at 3-4days postpartum : r=-.95, P=.9548, at 4-6wks postpartum : r=-.0960, P=.4733 and at 3-month postpartum : r=-.05, P=7306). On the contrary, the unemployed first-time mothers felt less maternal role strain when they received more support from their husband at 3-4 days postpartum(r=-.31, P=.0073) and at 4-6wks postpartum(r=-.23, P=.0490). 2. There was no difference of maternal role strain between two groups with regards to employment status(F=.97, P=.3270). But the maternal role strains of two groups were changed differently each other over time(F=3.89, P=.00234). Therefore, the 2nd hypothesis that "there was the difference in the maternal role strains with regard to employment status and over time" was rejected. 3. There was no difference in husband's support between the employed and the nonemployed first-time mothers(F=3.06, P=.0826). But there was a significant interaction between employment status and over time(F=3.64, P=.0267), so the support from husband of the employed and the unemployed first-time mothers was changed differently each other over time. The support from husband of the employed first-time mothers was lowered significantly and continuously at 4-6wks (F=5.20, P=.0263) and at 3-month postpartum(F=6.47, P=.0137) than at 3-4 days postpartum. On the contrary, there was no difference in change of husband's support of the employed first-time mothers between the 3-4 days and the 4-6wks postpartum(F=1.70, P=.1962) and between the 3-4 days and the 3-month postpartum(F=.21, P=.6513). Mean husband's support of the nonemployed first-time mothers was raised at 4-6wks postpartum than at 3-4 days postpartum but lowed at 3-month postpartum. The support form husband of both groups was tending downwards at 3-month postpartum than at 4-6wks postpartum, but the one between two groups was changed differently each other over time. The husband's support of the employed first-time mothers(M${\pm}$SD=64. 26${\pm}$8.63) was higher than the one of the nonemployed first-time mothers(M${\pm}$SD=59.16${\pm}$11.11) (t=-2.98, P=.0035), so the 3rd hypothesis that "there was the difference in the husband's support with regard to employment status and over time" was supported. On the basis of these conclusions, the following suggestion is proposed. This study examined the change and relationship between maternal role strain and husband's support in the employed and the nonemployed first-time mothers. So the further study regarding the comparison between the employed and the nonemployed multiparas is necessary.

• Korean Journal of Ecology and Environment
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• v.45 no.2
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• pp.158-173
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• 2012

The objectives of this study were to analyze the longitudinal gradient and temporal variations of water quality in Daecheong Reservoir in relation to the major inflowing streams from the watershed, during 2001~2010. For the study, we selected 7 main-stream sites of the reservoir along the main axis of the reservoir, from the headwater to the dam and 8 tributary streams. In-reservoir nutrients of TN and TP showed longitudinal declines from the headwater to the dam, which results in a distinct zonation of the riverine ($R_z$, M1~M3), transition ($T_z$, M4~M6), and lacustrine zone ($L_z$, M7) in water quality, as shown in other foreign reservoirs. Chlorophyll-a (CHL) and BOD as an indicator of organic matter, were maximum in the $T_z$. Concentration of total phosphorus (TP) was the highest (8.52 $mg\;L^{-1}$) on March in the $R_z$, and was the highest (165 ${\mu}g\;L^{-1}$) in the $L_z$ on July. Values of TN was the maximum (377 ${\mu}g\;L^{-1}$) on August in the $R_z$, and was the highest (3.76 $mg\;L^{-1}$) in the $L_z$ on August. Ionic dilution was evident during September~October, after the monsoon rain. The mean ratios of TN : TP, as an indicator of limiting factor, were 88, which indicates that nitrogen is a surplus for phytoplankton growth in this system. Nutrient analysis of inflowing streams showed that major nutrient sources were headwater streams of T1~T2 and Ockcheon-Stream of T5, and the most influential inflowing stream to the reservoir was T5, which is located in the mid-reservoir, and is directly influenced by the waste-water treatment plants. The key parameters, influenced by the monsoon rain, were TP and suspended solids (SS). Empirical models of trophic variables indicated that variations of CHL in the $R_z$ ($R^2$=0.044, p=0.264) and $T_z$ ($R^2$=0.126, p=0.054) were not accounted by TN, but were significant (p=0.032) in the $L_z$. The variation of the log-transformed $I_r$-CHL was not accounted ($R^2$=0.258, p=0.110) by $I_w$-TN of inflowing streams, but was determined ($R^2$=0.567, p=0.005) by $I_w$-TP of inflowing streams. In other words, TP inputs from the inflowing streams were the major determinants on the in-reservoir phytoplankton growth. Regression analysis of TN : TP suggested that the ratio was determined by P, rather than N. Overall, our data suggest that TP and suspended solids, during the summer flood period, should be reduced from the eutrophication control and P-input from Ockcheon-Stream should be controlled for water quality improvement.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.201-208
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• 2018

Purpose : The purpose of this study is to compare and analyze the set-up errors using the Combine IGRT with ExacTrac and CBCT phased in the treatment of Stereotatic Body Radiotherapy. Methods and materials : Patient who were treated Stereotatic Body Radiotherapy in the ulsan university hospital from May 2014 to november 2017 were classified as treatment area three brain, nine spine, three pelvis. First using ExacTrac Set-up error calibrated direction of Lateral(Lat), Longitudinal(Lng), Vertical(Vrt), Roll, Pitch, Yaw, after applied ExacTrac moving data in addition to use CBCT and set-up error calibrated direction of Lat, Lng, Vrt, Rotation(Rtn). Results : When using ExacTrac, the error in the brain region is Lat $0.18{\pm}0.25cm$, Lng $0.23{\pm}0.04cm$, Vrt $0.30{\pm}0.36cm$, Roll $0.36{\pm}0.21^{\circ}$, Pitch $1.72{\pm}0.62^{\circ}$, Yaw $1.80{\pm}1.21^{\circ}$, spine Lat $0.21{\pm}0.24cm$, Lng $0.27{\pm}0.36cm$, Vrt $0.26{\pm}0.42cm$, Roll $1.01{\pm}1.17^{\circ}$, Pitch $0.66{\pm}0.45^{\circ}$, Yaw $0.71{\pm}0.58^{\circ}$, pelvis Lat $0.20{\pm}0.16cm$, Lng $0.24{\pm}0.29cm$, Vrt $0.28{\pm}0.29cm$, Roll $0.83{\pm}0.21^{\circ}$, Pitch $0.57{\pm}0.45^{\circ}$, Yaw $0.52{\pm}0.27^{\circ}$ When CBCT is performed after the couch movement, the error in brain region is Lat $0.06{\pm}0.05cm$, Lng $0.07{\pm}0.06cm$, Vrt $0.00{\pm}0.00cm$, Rtn $0.0{\pm}0.0^{\circ}$, spine Lat $0.06{\pm}0.04cm$, Lng $0.16{\pm}0.30cm$, Vrt $0.08{\pm}0.08cm$, Rtn $0.00{\pm}0.00^{\circ}$, pelvis Lat $0.06{\pm}0.07cm$, Lng $0.04{\pm}0.05cm$, Vrt $0.06{\pm}0.04cm$, Rtn $0.0{\pm}0.0^{\circ}$. Conclusion : Combine IGRT with ExacTrac in addition to CBCT during Stereotatic Body Radiotherapy showed that it was possible to reduce the set-up error of patients compared to single ExacTrac. However, the application of Combine IGRT increases patient set-up verification time and absorption dose in the body for image acquisition. Therefore, depending on the patient's situation that using Combine IGRT to reduce the patient's set-up error can increase the radiation treatment effectiveness.