• The Journal of Korean Society for Radiation Therapy
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• v.21 no.1
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• pp.17-23
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• 2009

Purpose: In treating head and neck cancer, it is very important to irradiate uniform dose on the junction of the bilateral irradiation field of the upper head and neck and the anterior irradiation field of the lower neck. In order to improve dose distribution on the junction, this study attempted to correct non uniform dose resulting from under dose and over dose using the field-in-field technique in treating the anterior irradiation field of the lower neck and to apply the technique to the treatment of head and neck cancer through comparison with conventional treatment. Materials and Methods: In order to examine dose difference between the entry point and the exit point where beam diffusion happens in bilateral irradiation on the upper head and neck, we used an anthropomorphic phantom. Computer Tomography was applied to the anthropomorphic phantom, the dose of interest points was compared in radiation treatment planning, and it was corrected by calculating the dose ratio at the junction of the lower neck. Dose distribution on the junction of the irradiated field was determined by placing low-sensitivity film on the junction of the lower neck and measuring dose distribution on the conventional bilateral irradiation of the upper head and neck and on the anterior irradiation of the lower neck. In addition, using the field-in-field technique, which takes into account beam diffusion resulting from the bilateral irradiation of the upper head and neck, we measured difference in dose distribution on the junction in the anterior irradiation of the lower neck. In order to examine the dose at interest points on the junction, we compared and analyzed the change of dose at the interest points on the anthropomorphic phantom using a thermoluminescence dosimeter. Results: In case of dose sum with the bilateral irradiation of the upper head and neck when the field-in-field technique is applied to the junction of the lower neck in radiation treatment planning, The dose of under dose areas increased by 4.7~8.65%. The dose of over dose areas also decreased by 2.75~10.45%. Moreover, in the measurement using low-sensitivity film, the dose of under dose areas increased by 11.3%, and that of over dose areas decreased by 5.3%. In the measurement of interest point dose using a thermoluminescence dosimeter, the application of the field-in-field technique corrected under dose by minimum 7.5% and maximum 17.6%. Thus, with the technique, we could improve non.uniform dose distribution. Conclusion: By applying the field-in-field technique, which takes into account beam divergence in radiation treatment planning, we could reduce cold spots and hot spots through the correction of dose on the junction and, in particular, we could correct under dose at the entry point resulting from beam divergence. This study suggests that the clinical application of the field-in-field technique may reduce the risk of lymph node metastasis caused by under dose on the cervical lymph node.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.21-35
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• 1997

The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy is cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-20Pd-20Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electic furace and centrifugal casting machine in Ar atmoshpere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age-hardening characteristics of the small Au-containing Ag-pPd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, emergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, I. e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the Llo type face centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affedted by the Cu concentration. In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase(L1o type) and an Agrich ${\alpha}2$ phase occurred and a discontiunous precipitation occurred at the grain boundary. Form the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}\to{\alpha}+{\alpha}2+PdCu\to{\alpha}1+{\alpha}2+PdCu$ at Pd/Cu = 1 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Journal of Gastric Cancer
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• v.5 no.1
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• pp.23-28
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• 2005

Purpose: Bone metastasis is not a common event in patients with gastric cancer. Therefore, most studies of bone metastasis in such patients have been in the form of case reports, so the clinical features of the bone metastasis are not well understood. To clarify metastatic patterns, the efficacy of radiation or chemotherapy, and the prognosis, we analyzed 29 cases of patients with bone metastases after curative surgery for gastric cancer. Materials and Methods: Twenty-nine (29) gastric cancer patients with bone metastasis who underwent curative resection from January 1989 to December 2002 at the Departments of Surgery, Kangnam St. Mary's Hospital and Our Lady of Mercy's Hospital, The Catholic University of Korea, were analyzed. Results: Nineteen (19) patients were males and, 10 patients were females. The mean age of the patients was $53\pm12$ years. There were more Borrmann type-3 and type-4 cancers and more undifferentiated histologic types. Most of the original cancers were stage III or IV. The most frequently involved bone was the spine. Treatment after recurrence was done in 16 patients ($55.2\%$). The median survival time after recurrence of the patients who received treatment was seven (7) months ($0\∼75$ months in range), which was significantly longer than that of the patients who did not received treatment (P=0.019). However, there was no difference according to the treatment modality (P=0.388). Conclusion: Bone metastasis after a curative resection of gastric cancer tends to occur in Borrmann type-3 and type-4 cancers, cancers with undifferentiated histology and, in stage III/IV disease. The prognosis of bone metastasis is dismal, and aggressive treatment is the only way to prolong survival.

• Advances in pediatric surgery
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• v.9 no.1
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• pp.45-51
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• 2003

A nationwide survey on choledochal cyst was undertaken among 39 members of the Korean Association of Pediatric Surgeons. The members were required to complete a questionnaire and the case registration form for each patient during the five year period of 1997 to 2001. Three hundred and forty eight patients were registered from 32 institutions. The average number of patients per surgeon was one to two every year. The male to female ratio was 1:3.4. The age of patients on diagnosis was $49.0{\pm}44.4$ months. The geographic distribution was 34.8% in Seoul and Kyoungki-do, 33.3% in Kyoungsang-do, 17.9% in Cholla-do, and 8.5% in Choongchung-do, in order of frequency. The three common clinical presentations were abdominal pain (63.8%), vomiting (35.3%), and jaundice (29.1%). Only seven patients (2%) presented with classic triad, and 25 patients were diagnosed by antenatal ultrasonographic examination. According to the Todani Classification, 238 patients (7l.3%) were type 1, 3 (0.9%) type 11, and 93 (27.8%) type IV. At the time of the operation, three important associated conditions were choledocholithiasis in 45 patients (15.1%), liver fibrosis (Grade 1-4) in 35, and previous operative procedure for biliary diseases in 10. Associated anomalies were observed in 13 patients (3.8%). Three hundred thirty nine (98.8%) of 343 lesions were treated by Cyst excision and Roux-Y hepaticoiejunostomy. One hundred seventy-six patients had an anomalous arrangement of the pancreatobiliary ductal system (APBD): APBD was not in 92 patients, biliary duct joined to the pancreatic duct in 51, and pancreatic duct joined to the biliary duct in 26. There were 8.5% early, and 7.7% late phase operative complications. The major complications were bleeding, anastomotic leakage, and acute pancreatitis. The combination of acute abdomen and choledochal cyst may suggest spontaneous rupture. Because of the development of late intrahepatic bile duct stones, long term follow up after cyst excision and hepaticojejunostomy is required. The optimal time of surgical intervention should also be considered in the situation of routine use of antenatal ultrasonographic examination. This is the first review of the choledochal cyst in Korea and provides baseline data for future comparisons.

• Sleep Medicine and Psychophysiology
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• v.12 no.1
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• pp.39-44
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• 2005

Objectives: Much attention has been paid to sleep apnea syndrome (SAS) in the elderly because of its high prevalence. It is expected that SAS in the elderly has both similarities and differences compared to SAS in the young or middle-aged populations. The aim of this study was to elucidate the characteristics and consequences of SAS in the elderly. Methods: In this study we included 210 young or middle-aged adults between 23 and 59 years (20 women and 190 men) and 65 older adults between 60 and 83 years of age (16 women and 49 men). Respiratory disturbance indices (RDIs) of the study subjects were more than 5 in an overnight polysomnography. They completed the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Informations about body mass index (BMI), neck, waist, and hip measurements, and blood pressure were obtained. Results: No difference was observed between older adults with SAS (older SAS) and adults aged under 60 with SAS (SAS aged under 60) in RDI, apnea index, % time of oxygen saturation less than 90%, and PSQI. Obstructive apnea index and oxygen desaturation index (ODI) were lower in older SAS. Compared to SAS aged under 60, lowest oxygen saturation and central apnea index were higher in older SAS, but they were statistically not significant. BMI and neck circumference were significantly lower in older SAS compared to SAS aged under 60. Diastolic blood pressure was lower in older SAS compared to SAS aged under 60 with no difference in systolic blood pressure. Older SAS showed lower scores in ESS than SAS aged under 60. Significant correlation was observed between RDI and BMI in SAS aged under 60, but not in the case of older SAS. The relationships between RDI and neck circumference, systolic and diastolic pressure, and ESS were similar. Conclusions: The elderly with SAS were not over-weight and there was no relationship between body weight and the severity of SAS. Also, the behavioral and cardiovascular effects of SAS were not marked in the elderly, which might be partly explained by decreased ODI and relatively higher lowest oxygen saturation in older SAS. The normal aging process, aside from increased body weight, might contribute to the development of SAS in the elderly with modest complications.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.705-713
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• 1998

Background: An association between diabetes and tuberculosis has long been implied. The severity of diabetes appears to correlate with the degree of tuberculous activity. Methods: A retrospective chart review of 82 patients with active pulmonary tuberculosis in diabetics (DMTB) and 83 patients with active pulmonary tuberculosis in nondiabetics (Non-DMTB) admitted to the Kyung Hee Medical Center between January 1995 and December 1996 was underiaken. Results: The sex ratio of DMTB was 58 : 24, and that of Non-DMTB was 62 : 21. Male patients predominated in both groups. The highest incidence of DMTB was 6th and 7th decades and that of Non-DMTB was 3rd and 4th decades. In case which the tuberculosis developed after diagnosis of diabetes, the prevalence of pulmonary tuberculosis was the highest in diabetes for 5-10 years. On chest X-ray findings, the moderate advanced tuberculosis cases were the most common (60.9% in DMTTB and 50.6% in Non-DMTB). There was no relation between the degree of tuberculosis activity on chest x-ray(minimal, moderate, and far advanced tuberculosis) and presence of diabetes. The incidence of lower lung field tuberculosis in DMTB was significantly higher than Non-DMTB(p<0.05). The multiple lobe involvement was the predominant chest roentgenographic finding in both groups. There was no significant difference of treatment response between DMTB and Non-DMTB. There was no relationship between initial HbA1c and the severity of pulmonary tuberculosis on chest X-ray. During treatment of pulmonary tuberculosis in excellently and well controlled diabetes, the cure rate of pulmonary tuberculosis was significantly higher than the poorly controlled diabetes and the rate of treatment failure was significantly lower than poorly controlled diabetes. (p<0.05). Conclusion: Poor control of blood glucose is related with increased rate of treatment failure in pulmonary tuberculosis with diabetes mellitus. Further investigation will be needed to study the mechanisms of treatment failure in poorly controlled diabetics with pulmonary tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.277-288
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• 1994

Objectives : Multiple lung cancers and/or precancerous lesions can be developed because many bronchi are exposed to carcinogens simultaneously according to the concept of "Field Cancerization". We had performed a careful bronchoscopic examination and analysed the patients of double bronchial lesions who received the separate pathologic evaluation. Methods : We studied 21 patients of double bronchial lesions among 1855 patients of bronchoscopic examination from April 1990 to December 1993 in Korea Cancer Center Hospital. We classified the patients into three groups(double malignancies of different histology, double malignancies of same histology, and combination of malignant and benign lesions) and analysed the histologic type, location, radiologic findings, and clinical parameters. Results : Among 21 patients, six patients had double malignancies of different histology, eight had double malignancies of same histology, and seven had combination of malignant and benign lesions. Out of 14 double malignant cases, 11 cases are considered as synchronous multiple primary lung cancers. Combination of squamous cell carcinomas was found in 5 cases, combination of small cell carcinoma and squamous cell carcinoma was found in 4 cases. Combination of adenocarcinoma and squamous cell carcinoma and combination of squamous cell carcinoma and poorly differentiated carcinoma were found in 1 case respectively. All patients of synchtonous multiple primary lung cancers were male and had long smoking history(average 40 pack years). Among 21 cases of double bronchial lesions, only one lesion could be detected by prebronchoscopic radiologic examination including chest CT in 15 cases. Conclusions : The presence of double bronchial lesions including multiple primary lung cancers and the limitation of radiologic examination to detect early bronchial lesions encourage us to examine the whole bronchi carefully and to perform pathologic evaluations.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.591-598
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• 2001

Background : Primary adenoid cystic carcinoma arising in the bronchus is an uncommon disease that is histologically and ultrastructurally identical to the salivary gland tumor of the same name and regarded as a slow growing low-grade malignancy. We examined its clinical characteristics. Method : We collected 13 Korean cases of primary adenoid cystic carcinoma arising in the bronchus including 5 cases of our own and 8 cases from the literature. Result : The patients ages ranged from 20 to 74. Men numbered 9 and women 4. The presenting symptoms were cough, dyspnea, and hemoptysis. The fiberoptic bronchoscopic findings were primarily hypervascular polypoid mass with a smooth surface that obstructed airway totally or near totally. There were three inoperable cases including two cases with distant metastasis to bone or cervical lymph node and one case with mediastinal invasion. The remaining 10 patients underwent surgical resection. Among them, two patients received postoperative radiotherapy. The median survival was 21 months in the 8 surgical and evaluable cases. One patient lived 13 years without recurrence. The prognosis was relatively favorable in operable cases. Conclusion : It was not common for primary adenoid cystic carcinoma arising in the bronchus to have distant metastasis or invasion to the mediastinum on presentation. The prognosis was relatively favorable in operable cases. It would be important to perform flexible bronchoscopy for early diagnosis and to do surgical treatment if possible.

• Progress in Medical Physics
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• v.23 no.2
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• pp.81-90
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• 2012

The effect of setup uncertainties on CTV dose and the correlation between setup uncertainties and setup margin were evaluated by Monte Carlo based numerical simulation. Patient specific information of IMRT treatment plan for rectal cancer designed on the VARIAN Eclipse planning system was utilized for the Monte Carlo simulation program including the planned dose distribution and tumor volume information of a rectal cancer patient. The simulation program was developed for the purpose of the study on Linux environment using open source packages, GNU C++ and ROOT data analysis framework. All misalignments of patient setup were assumed to follow the central limit theorem. Thus systematic and random errors were generated according to the gaussian statistics with a given standard deviation as simulation input parameter. After the setup error simulations, the change of dose in CTV volume was analyzed with the simulation result. In order to verify the conventional margin recipe, the correlation between setup error and setup margin was compared with the margin formula developed on three dimensional conformal radiation therapy. The simulation was performed total 2,000 times for each simulation input of systematic and random errors independently. The size of standard deviation for generating patient setup errors was changed from 1 mm to 10 mm with 1 mm step. In case for the systematic error the minimum dose on CTV $D_{min}^{stat{\cdot}}$ was decreased from 100.4 to 72.50% and the mean dose $\bar{D}_{syst{\cdot}}$ was decreased from 100.45% to 97.88%. However the standard deviation of dose distribution in CTV volume was increased from 0.02% to 3.33%. The effect of random error gave the same result of a reduction of mean and minimum dose to CTV volume. It was found that the minimum dose on CTV volume $D_{min}^{rand{\cdot}}$ was reduced from 100.45% to 94.80% and the mean dose to CTV $\bar{D}_{rand{\cdot}}$ was decreased from 100.46% to 97.87%. Like systematic error, the standard deviation of CTV dose ${\Delta}D_{rand}$ was increased from 0.01% to 0.63%. After calculating a size of margin for each systematic and random error the "population ratio" was introduced and applied to verify margin recipe. It was found that the conventional margin formula satisfy margin object on IMRT treatment for rectal cancer. It is considered that the developed Monte-carlo based simulation program might be useful to study for patient setup error and dose coverage in CTV volume due to variations of margin size and setup error.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.457-465
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• 1999

Objective: The presence of Y chromosome in patients with gonadal dysgenesis is related to the risk of gonadoblastoma. Since the patients with abnormal sexual differentiation may have cryptic Y mosaicism, it is important to detect the presence of Y material in these patients. But sometimes it is difficult to detect Y material only with karyotyping. This study was performed to evaluate the usefulness of the SRY gene screening in blood and gonad by using PCR in detecting the presence of Y material and possible tissue mosaicism in patients with gonadal dysgenesis as Turner syndrome and 46,XY pure gonadal dysgenesis (PGD, Swyer syndrome). Method: In 26 patients with gonadal dysgenesis, we screened for Y material by using PCR for SRY gene in peripheral leukocytes and in gonadal tissues of some patients. They were 22 cases of Turner syndrome (7 45,XO, 2 46,Xi(Xq), 3 45,XO/46,XX, 5 45,XO/46,Xi(Xq), 1 45, XO/46,XY, 1 45,XO/46,Xi(Yq), 1 45,XO/47,XYY, 1 46,XX,del(X)(q24) and 1 46,X,+mar) and 4 cases of 46,XY pure gonadal dysgenesis. PCR for SRY gene in the gonadal tissue was performed in 5 Turner syndrome and 2 PGD to determine the cryptic Y mosaicism between blood and gonad. Results: By using PCR analysis for SRY, Y chromosome material was detected in the blood of 4 of 22 Turner syndrome patients (45,XO/46,Xi(Xq), 45,XO/46,Xi(Yq), 45,XO/46,XY, and 45, XO/47,XYY), 3 of 4 46,XY pure gonadal dysgenesis. Discrepancy between karyotyping and blood PCR for SRY was noted in 1 Turner syndrome (45,XO/46,Xi(Xq)) and 1 PGD. Laparoscopic gonadectomy was performed in Y containing or SRY positive cases. In addition, PCR analysis for SRY in the gonads of 5 Turner syndrome and 2 PGD showed discrepancy between blood and gonad or between both gonads in 3 Turner syndrome (45,XO/46,Xi(Xq), 45,XO/46,Xi(Y q), 45,XO/46,XY) and 2 PGD patients. Conclusion: In gonadal dysgenesis, PCR analysis for SRY gene is useful to detect the cryptic Y mosaicism that is sometimes undetected by karyotyping. And since there may be tissue mosaicism, it is necessary to evaluate Y mosaicism in various tissues even in the case without Y chromosome on karyotyping.