• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.210-214
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• 2010

Purpose : Cisplatin is highly effective for the treatment of solid tumors in children. However, the clinical use of cisplatin is limited by its ototoxicity. The aim of this study was to evaluate the ototoxicity in children treated with cisplatin. Method : We performed a single institution retrospective analysis of pediatric oncology patients who received cisplatin therapy between January 2001 and January 2008. Thirty-seven patients with sufficient medical and audiologic data were included in this study. Results : The median age at the time of diagnosis was 10.7 (range 3.8-6.7) years. There were 16 males and 21 females. The underlying diseases were osteosarcoma (15 cases), medulloblastoma (14 cases), germ cell tumors (7 cases), and hepatoblastoma (1 case). The median individual dose was $100mg/m^2$/cycle (56-200). The median cumulative dose was $480mg/m^2$ (200-1,490). Sixteen patients (43%) received cranial radiotherapy. Of the 37 patients, 17 developed hearing loss, leading to an overall incidence of 46%. Logistic regression showed that age at treatment (P =0.04) and cumulative dose of cisplatin (P =0.005) were the significant risk factors in predicting hearing loss in children treated with cisplatin. In all the patients who had hearing loss, there was neither improvement nor aggravation during the follow-up (3-8 months). Conclusion : The cumulative dose of cisplatin (>$500mg/m^2$) and younger age at treatment (<12 years) were 2 most important risk factors for ototoxicity in patients treated with cisplatin. Serial audiometric evaluations are needed in the patients with risk factors during and after cisplatin treatment.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.573-579
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• 2008

Background: Composite valve graft replacement is currently the treatment of choice for a wide variety of the lesions of aortic root disease. The purpose of this study was to explore the results of aortic root replacement after using the Cabrol technique over a 13-year period at our institution, and we analyzed the results to help surgeons make better decisions when repairing aortic root disease. Material and Method: Between January 1994 and December 2006, twenty-five patients underwent a Cabrol technique operation at our institution. The mean patient age was $43.7{\pm}14.1$ years old (range: $6{\sim}65$ years) and the male and female ratio was 21:4 (84% : 16%). The patients' follow-up was 100% complete, and the mean follow-up period was $60.7{\pm}50.4$ (range:$1{\sim}162$) months. Annuloaortic ectasia (n=18) was the most frequent cause of aortic disease in this series, followed by aortic dissection (n=7). The mean cardiopulmonary bypass time was $177.2{\pm}44.9$ minutes and the mean aortic cross clamping time was $123.4{\pm}34.1$ minutes. Nine patients were checked with MDCT (Multidetector computed tomography) for evaluating a well functioning secondary graft and the coronary anastomosis site. Result: The early mortality rate was 4% (1 of 25 patients). A significant stenosis, kinking or occlusion of the secondary graft was detected by MDCT in 4 patients. The overall survival rate was 88%. Conclusion: The Cabrol technique demonstrated a significant incidence of long-term complications such as secondary graft stenosis or obstruction. It could be used when the modified Bentall technique is not feasible.

• Health Policy and Management
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• v.20 no.1
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• pp.103-124
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• 2010

Objectives: The out-of-pocket payment (OOP) of the Industrial Accident Compensation Insurance (IACI) in Korea was investigated empirically in terms of its incidence, magnitude and factors influencing them. Methods: The subjects were sampled with stratified, randomized methods among medical institutions of which the number of monthly IACI claims exceeded its median as of May 2008. Out of 204 institutions selected, 118 institutions (57.8%) responded to this survey. A total of 24,826 episodes(2,457 inpatient and 22,369 outpatient episodes) were included in this analysis. The incidence and magnitude of OOP of IACI were calculated by characteristics of institution as well as patient. Factors that affected the incidence and magnitude of OOP were investigated through multi-level analysis. Results: The overall incidence of OOP of IACI was 9.9% (25.6% for inpatient and 8.2% for outpatient) and the percentage of OOP among total expenditures was 8.3% on average (7.6% for inpatient and 26.8% for outpatient); 25.2% at traditional oriental medicine hospitals, 9.5% at general hospitals and 2.5% at the industrial-accident-designated medical institutions. The incidence of OOP of IACI was influenced by hospital size, ownership, longer duration of designation (over 5 years) and length of stay. On the other hand, its magnitude was influenced by medium-sized hospital, public hospital, location of large city and length of stay. Extra charges for upper grade room which accommodates less than 4 patients and treatment by specialists were the leading contributors to the magnitude of OOP of IACI. Conclusion: The incidence and magnitude OOP of IACI varied in institution type and were influenced by both institutional and patient's factors. In order to achieve the goal of Industrial Accident Compensation Insurance, appropriate level of compensation, that is, no incidence of OOP, for accident and disease of workers, it is necessary to take measures to reduce incidence and magnitude of OOP.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.416-424
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• 2017

This study was conducted to examine the awareness of workers in public institutions of automated external defibrillators, their usage intention and related educational experience in an effort to increase the efficiency of education and the rate of automated external defibrillator usage in emergency situations. The subjects in this study were 243 selected. male and female adults who worked in public institutions in Gangwon Province. A survey was conducted from June 13 to August 21, 2016. The statistical analysis was based on the frequency analysis and the $X^2$-test. There were significant differences among the public institution workers awareness of how to use an automated external defibrillator according to gender (${\chi}^2=6.32$, p<0.05) and academic credentials (${\chi}^2=5.91$, p<0.05). Additionally, there were significant differences in usage intention according to academic background (${\chi}^2=5.70$, p<0.05). The most common reason for having no intention to use an automated external defibrillator for patients with cardiac arrest was that the respondents did not know how to use it (31.5%). There were also significant differences in educational experience with automated external defibrillators according to age (${\chi}^2=6.15$, p<0.05), academic credentials (${\chi}^2=11.56$, p<0.01) and career (${\chi}^2=11.92$, p<0.01). The most common form of education that the workers received pertaining to automated external defibrillators was a combination of theoretical and practical education, which represented 55.9%. The findings of the study seem to suggest that workers in public institutions used by many people must receive compulsory standard education regarding automated external defibrillators and try to boost the revival rate of patients with cardiac arrest in real emergency situations.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.78-83
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• 2008

Purpose : Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Although survival rate of osteosarcoma patients has markedly improved, about 20-30% of patients still have a relapse. This study was aimed to find factors that influence postrelapse survival of osteosarcoma in childhood and adolescents. Methods : Between 1985 and 2004, of 461 patients who were diagnosed and treated as osteosarcoma in Korean Cancer Center Hospital, 180 patients with recurrent osteosarcoma were retrospectively reviewed. We examined survival rates and analyzed prognostic factors, such as relapse site, post-relapse treatment methods, pathologic response to neoadjuvnat chemotherapy, metastasis at first diagnosis, and relapse free interval. Results : The overall recurrence rate of patients with osteosarcoma was 39%. The 5-year and 10-year postrelapse survival rates in the recurrent osteosarcoma were 13% and 4%, respectively. The 5-year post-relapse survival rate was influenced by site of relapse (lung, 39%; local, 0%; lung & bone, 25%; others, 12%; P<0.05), relapse-free interval (<12 months, 13%; ${\geq}12$ months, 44%, P<0.05), and post-relapse treatment methods (with surgery, 38%; without surgery, 11%; P<0.05). Conclusion : The survival rate of recurrent case is very low after 10 years, so new second-line chemotherapy and active treatment is needed to increase survival. Aggressive surgery with the removal of recurrence sites combined with multi-agent chemotherapy could either cure patients with recurrent osteosarcoma or significantly prolong their survival.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.281-287
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• 2014

Purpose : The purpose of this study is to compare the plan quality of volumetric-modulated arc therapy (VMAT) and intensity-modulated radiation therapy (IMRT) for the treatment of orbital lymphoma. IMRT, partial single arc(SA) and partial-double arc(DA) VMAT plans for four patients with orbital lymphoma treated at our institution were used for this study. Conformity Index(CI), Paddick's Conformity Index(PCI) and Homogeneity Index(HI) of planning target volume(PTV) were used to evaluate dosimetric quality of each plan. The Monitor Unit (MU), treatment time and dose of ipsilateral lens from each type of plan were measured for comparison. Materials and Methods : The CI of PTV for IMRT, SA and DA were measured as 0.88, 0.86, 0.92. The PCI of DA was the lowest as 1.33. Also HI of DA was the lowest in measured plans as 1.15. Mean dose of lens, lacrimal gland, optic chiasm, the opposite optic nerve and both orbit was analyzed with V30, V20, V10, V5. The result showed that the lowest dose in IMRT highest in SA in opposite lens, lacrimal gland, optic nerve, orbit. Results : Treatment time and average MU of IMRT was about three times higher than SA. Conclusion : Considering the superior plan quality as well as the delivery efficiency of VMAT compared with that of IMRT, VMAT may be the preferred modality for treating orbital lymphoma.

• Progress in Medical Physics
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• v.25 no.3
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• pp.185-192
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• 2014

The purpose of this study is to evaluate the results for the quality assurance through a statistical analysis on the output characteristics of linear accelerators belonging to Yeungnam University Medical Center by using the Shewhart-type chart, Exponentially weighted moving average chart (EWMA) chart, and process capability indices $C_p$ and $C_{pk}$. To achieve this, we used the output values measured using respective treatment devices (21EX, 21EX-S, and Novalis Tx) by medical physicists every month from September, 2012 to April, 2014. The output characteristics of treatment devices followed the IAEA TRS-398 guidelines, and the measurements included photon beams of 6 MV, 10 MV, and 15 MV and electron beams of 4 MeV, 6 MeV, 9 MeV, 12 MeV, 16MeV, and 20 MeV. The statistical analysis was done for the output characteristics measured, and was corrected every month. The width of control limit of weighting factors and measurement values were calculated as ${\lambda}=0.10$ and L=2.703, respectively; and the process capability indices $C_p$ and $C_{pk}$ were greater than or equal to 1 for all energies of the linear accelerators (21EX, 21EX-S, and Novalis Tx). Measured values of output doses with drastic and minor changes were found through the Shewhart-type chart and EWMA chart, respectively. The process capability indices $C_p$ and $C_{pk}$ of the treatment devices in our institution were, respectively, 2.384 and 2.136 for 21EX, 1.917 and 1.682 for 21EX-S, and 2.895 and 2.473 for Novalis Tx, proving that Novalis Tx has the most stable and accurate output characteristics.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.331-339
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• 2014

To test feasibility of proton arc therapy (PAT) in the treatment of para-aortic lymph node tumor and compare its dosimetric properties with advanced radiotherapy techniques such as intensity modulated radiation therapy (IMRT) and conventional 3D conformal proton beam therapy (PBT). The treatment plans for para-aortic lymph node tumor were planned for 9 patients treated at our institution using IMRT, PBT, and PAT. Feasibility test and dosimetric evaluation were based on comparisons of dose volume histograms (DVHs) which reveal mean dose, $D_{30%}$, $D_{60%}$, $D_{90%}$, $V_{30%}$, $V_{60%}$, $V_{90%}$, organ equivalent doses (OEDs), normal tissue complication probability (NTCP), homogeneity index (HI) and conformity index (CI). The average doses delivered by PAT to the liver, kidney, small bowel, duodenum, stomach were 7.6%, 3%, 17.3%, 26.7%, and 14.4%, of the prescription dose (PD), respectively, which is higher than the doses delivered by IMRT (0.4%, 7.2%, 14.2%, 15.9%, and 12.8%, respectively) and PBT (4.9%, 0.5%, 14.12%, 16.1% 9.9%, respectively). The average homogeneity index and conformity index of tumor using PAT were 12.1 and 1.21, respectively which were much better than IMRT (21.5 and 1.47, respectively) and comparable to PBT (13.1 and 1.23, respectively). The result shows that both NTCP and OED of PAT are generally lower than IMRT and PBT. This study demonstrates that PAT is better in target conformity and homogeneity than IMRT and PBT but worse than IMRT and PBT for most of dosimetric factor which indicate that PAT is not recommended for the treatment of para-aortic lymph node tumor.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.22-27
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• 2009

Background: Coronary artery bypass grafting (CABG) is the standard surgical treatment for coronary artery disease. Although there are many clinical reviews of the long term results after CABG in the Western countries, not many such studies have been done for Korea. Therefore, we reviewed the long term clinical results for the patients who underwent CABG at our hospital. Material and Method: We retrospectively reviewed the medical records of 342 patients who underwent CABG at our hospital from February 1984 to December 2006, which is when CABG was first performed in our institution. A total of 286 patients (83.6%) were able to be followed-up, and the mean follow-up period was $75.7{\pm}46.1$ months. Result: The early mortality rate was 5.6%, and late mortality rate was 23.1%. The one-year survival rate, the five-year survival rate, the ten-year survival rate and the fifteen-year survival rate were 91.5%, 82.1%, 60.7% and 50.0%, respectively. The survival rate was significantly lower for the patients over the age of 60 (p=0.002) and for those with diabetes mellitus (p=0.000), hypertension (p=0.002), multivessel disease (p=0.006) and left ventricular dysfunction (p=0.015). No significant difference was observed between the genders. Multivariate analysis showed that the statistically significant risk factors were diabetes mellitus (p=0.001), age (p=0.005) and those cases for which the left internal thoracic artery was not used (p=0.037). Conclusion: CABG is the effective method of treatment for coronary artery disease. Therefore, active usage of the internal thoracic artery and appropriate medical treatment after surgery, and especially for diabetes mellitus patients, are mandatory for achieving good long-term survival.

• The Journal of Korean Society for Radiation Therapy
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• v.22 no.1
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• pp.47-51
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• 2010

Purpose: In the treatment of high-energy protons Air gap (the distance between the patient and the exit Beam) Lateral Penumbra of the changes to the increase in the radiation fields can form unnecessary and Increase the maximum dose at the site of treatment and reduced the minimum dose homogeneity of dose distributions can decline. Air gap due to this change in dose distribution compared to investigate studied. Materials and Methods: Received proton therapy at our institution Lung, Liver patients were selected and the size of six other Air gap in Field A and Field B 2, 4, 6, 8, 10 cm Proton external beam planning system by setting up a treatment plan established. Air gap according to the Lateral Penumbra area and DVH (Dose Volume Histogram) to compare the maximum dose and minimum dose of PCTV areas were compared. In addition, the dose homogeneity within PCTV Homogeneity index to know the value and compared. Results: Air gap (2, 4, 6, 8, 10 cm) at each change in field size were analyzed according to the Lateral Penumbra region Field A Change in the Air gap 2~10 cm by 1.36~1.75 cm, the average continuously increased about 28.7% and Field B Change in the Air gap 2~10 cm by 1.36~1.75 cm, the average continuously increased about 31.6%. The result of DVH analysis for relative dose of the maximum dose According to Air gap 2~10 cm is the mean average of 110.3% from 108.1% to a sustained increased by approximately 2.03% and The average relative dose of minimum dose is the mean average of 93.9% percent to 90.8 percent from the continuous decrease of about 3.31 percent. The result of Homogeneity index value to the according to Air gap 2~10 cm is the 2-fold increase from 1.09 to 2.6. Conclusion: In proton therapy case, we can see the increasing of lateral penumbra area when airgap getting increase. And increasing of Dmax and decreasing Dmin in the field are making increase homogeneity index, So we can realize there are not so good homogeneity in the PCTV. Therefore we should try to minimize air gap in proton therapy case.