• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.321-327
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• 2014

Purpose : To verify the accuracy of the Ecilpse's dose calculation algorithm(AAA:Analytic anisotropic algorithm) in case of a radiation treatment on Inhomogeneous tissues using FFF beam comparing dose distribution at TPS with actual distribution. Materials and Methods : After acquiring CT images for radiation treatment by the location of tumors and sizes using the solid water phantoms, cork and chest tumor phantom made of paraffin, we established the treatment plan for 6MV photon therapy using our radiation treatment planning system for chest SABR, Ecilpse's AAA(Analytic anisotropic algorithm). According to the completed plan, using our TrueBeam STx(Varian medical system, Palo Alto, CA), we irradiated radiation on the chest tumor phantom on which EBT2 films are inserted and evaluated the dose value of the treatment plan and that of the actual phantom on Inhomogeneous tissue. Results : The difference of the dose value between TPS and measurement at the medial target is 1.28~2.7%, and, at the side of target including inhomogeneous tissues, the difference is 2.02%~7.40% at Ant, 4.46%~14.84% at Post, 0.98%~7.12% at Rt, 1.36%~4.08% at Lt, 2.38%~4.98% at Sup, and 0.94%~3.54% at Inf. Conclusion : In this study, we discovered the possibility of dose calculation's errors caused by FFF beam's characteristics and the inhomogeneous tissues when we do SBRT for inhomogeneous tissues. SBRT which is most popular therapy method needs high accuracy because it irradiates high dose radiation in small fraction. So, it is supposed that ideal treatment is possible if we minimize the errors when planning for treatment through more study about organ's characteristics like Inhomogeneous tissues and FFF beam's characteristics.

• Journal of Korean Neurosurgical Society
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• v.30 no.6
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• pp.705-710
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• 2001

Objective : Postoperative seizure is a well documented complication of aneurysm surgery. The purpose of the present study was to analyze risk factors for postoperative seizure. Methods : Between January 1990 and December 1996, we performed craniotomy for ruptured cerebral aneurysms in 321 patients. Among them 206 patients who could be followed up for more than 1 year(range, 1 to 4.6 years) were enrolled to present study. All patients were treated with anticonvulsants for 3 to 18 months postoperatively. We analyze the incidence of postoperative seizure in different sex and age groups, and risk factors associated with postoperative seizures following aneurysm rupture. For statistical processing chi-square test and Fisher's exact test were used. Results : In the follow-up period of 1 to 4.6 years(mean, 1.8 years) postoperative seizure appeared in 18 out of 206 patients(8.7%). Mean latency between the operation and the first seizure was 6 months(range, 3 weeks to 18 months). The age of the patients has significant influence on the risk of seizure, it occurred more often in younger patients(p =0.0014). Aneurysm location in the MCA was associated with a significantly a higher risk of seizure(p = 0.042). Eight patients(19%) out of 42 patients who suffered delayed ischemic neurologic deficit(DID) developed seizure. Delayed ischemic neurologic deficit was associated with significantly a higher risk of seizure(p =0.019). Infarct and hypertension were associated with significantly a higher risk of seizure(p <0.05). pre- or postoperative intracranial hematoma(intracerebral or epidural hematoma) was associated with significantly a higher risk of seizure(p <0.0001). H-H grade, Fisher grade, Glasgow Outcome Scale of patients and timing of operation after subarachnoid hemorrhage had no significant relation with the risk of seizure. Conclusion : Factors associated with the development of postoperative seizure were middle cerebral artery aneurysm, delayed ischemic neurologic deficit, infarct on late postoperative CT scan, hypertension, pre or postoperative intracranial hematoma(intracerebral or epidural hematoma). Identification of the risk factors may be help to focus the antiepileptic drug threapy in cases prone to develop seizures. Prospective evaluation is indicated.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.239-245
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• 2016

Purpose: The purpose of this study was to identify clinical complications in removable partial denture (RPD) with implant-supported surveyed prostheses, and to analyze the factors associated with the complications such as location of the implant, splinting adjacent prostheses, the type of retentive clasps, Kennedy classification, and opposing dentition. Materials and Methods: A retrospective clinical study was carried out for 11 patients (7 male, 4 female), mean age of 67.5, who received RPD with Implant-supported surveyed prostheses between 2000 and 2016. The mechanical complications of 11 RPDs and 37 supporting implant prostheses and the state of natural teeth and peripheral soft tissue were examined. Then the factors associated with the complications were analyzed. Results: The average of 3.4 implant-supported prostheses were used for each RPD. Complications found during the follow-up period of an average of 42.1 months were in order of dislodgement of temporary cement-retained prostheses, opposing tooth fracture/mobility, screw fracture/loosening, clasp loosening, veneer porcelain fracture, marginal bone resorption and mobility of implant, artificial tooth fracture. Complications occurred more frequently in anterior region compared to posterior region, non-splinted prostheses compared to splinted prostheses, surveyed prostheses applied by wrought wire clasp compared to other clasps, and natural dentition compared to other removable prostheses as opposing dentition. There were no significant differences in complications according to the Kennedy classification. Conclusion: All implant-assisted RPD functioned successfully throughout the follow-up. However, further clinical studies are necessary because the clinical evidences are still not enough to guarantee the satisfactory prognosis of implant-assisted RPD for long-term result.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.81-86
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• 2001

Prupose : To evaluate the role of linac based radiosurgery (RS) in the treatment of meningiomas, we retrospectively analyzed the results of clinical and follow up CT/MRI studies. Methods and Materials : From the 1988 July to 1998 April, twenty patients of meningioma had been treated with 6 MV linear accelerator based radiosurgery. Of the 20 patients, four $(20\%)$ were male and 16 $(80\%)$ were female. Mean age was 51 years old ($22\~78$ years old). Majority of intracranial location of tumor for RS were parasagittal and sphenoid wing area. RS was done for primary treatment in 6 $(30\%)$, postoperative residual lesions in 11 $(55\%)$ and regrowth after surgery in 3 $(15\%)$. Mean tumor volume was $5.72\;cm^3\;(0.78\~15.1\;cm^3)$ and secondary collimator size was 2.04 cm $(1\~3\;cm)$. The periphery of tumor margin was prescribed with the mean dose of 19.6 Gy $(9\~30\;Gy)$ which was $40\~90\%$ of the tumor center dose. The follow up duration ranged from 2.5 to 109 months (median 53 months). Annual CT/MRI scan was checked. Results : By the follow up imaging studies, the tumor volume was reduced in 5 cases $(25\%)$, arrested growth in 14 cases $(70\%)$, and increased size in 1 case $(15\%)$. Among these responsive and stable 19 patients by imaging studies, there showed loss of contrast enhancement after CT/MRI in four patients. In clinical response, nine $(45\%)$ patients were considered improved condition, 10 $(50\%)$ patients were stable and one $(5\%)$ was worsened to be operated. This partly resulted in necrosis after surgery. Conclusion : The overall control rate of meningiomas with linac based RS was $95\%$ by both imaging follow-up and clinical evaluation. With this results, linac based RS is considered safe and effective treatment method for meningioma.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.123-127
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• 1978

The major objective of this research is to identify those hospital characteristics that best explain cost variation among hospitals and to formulate linear models that can predict hospital costs. Specific emphasis is placed on hospital output, that is, the identification of diagnosis related patient groups (DRGs) which are medically meaningful and demonstrate similar patterns of hospital resource consumption. A casemix index is developed based on the DRGs identified. Considering the common problems encountered in previous hospital cost research, the following study requirements are estab-lished for fulfilling the objectives of this research: 1. Selection of hospitals that exercise similar medical and fiscal practices. 2. Identification of an appropriate data collection mechanism in which demographic and medical characteristics of individual patients as well as accurate and comparable cost information can be derived. 3. Development of a patient classification system in which all the patients treated in hospitals are able to be split into mutually exclusive categories with consistent and stable patterns of resource consumption. 4. Development of a cost finding mechanism through which patient groups' costs can be made comparable across hospitals. A data set of Medicare patients prepared by the Social Security Administration was selected for the study analysis. The data set contained 27,229 record abstracts of Medicare patients discharged from all but one short-term general hospital in Connecticut during the period from January 1, 1971, to December 31, 1972. Each record abstract contained demographic and diagnostic information, as well as charges for specific medical services received. The 'AUT-OGRP System' was used to generate 198 DRGs in which the entire range of Medicare patients were split into mutually exclusive categories, each of which shows a consistent and stable pattern of resource consumption. The 'Departmental Method' was used to generate cost information for the groups of Medicare patients that would be comparable across hospitals. To fulfill the study objectives, an extensive analysis was conducted in the following areas: 1. Analysis of DRGs: in which the level of resource use of each DRG was determined, the length of stay or death rate of each DRG in relation to resource use was characterized, and underlying patterns of the relationships among DRG costs were explained. 2. Exploration of resource use profiles of hospitals; in which the magnitude of differences in the resource uses or death rates incurred in the treatment of Medicare patients among the study hospitals was explored. 3. Casemix analysis; in which four types of casemix-related indices were generated, and the significance of these indices in the explanation of hospital costs was examined. 4. Formulation of linear models to predict hospital costs of Medicare patients; in which nine independent variables (i. e., casemix index, hospital size, complexity of service, teaching activity, location, casemix-adjusted death. rate index, occupancy rate, and casemix-adjusted length of stay index) were used for determining factors in hospital costs. Results from the study analysis indicated that: 1. The system of 198 DRGs for Medicare patient classification was demonstrated not only as a strong tool for determining the pattern of hospital resource utilization of Medicare patients, but also for categorizing patients by their severity of illness. 2. The wei틴fed mean total case cost (TOTC) of the study hospitals for Medicare patients during the study years was $11,27.02 with a standard deviation of $117.20. The hospital with the highest average TOTC ($1538.15) was 2.08 times more expensive than the hospital with the lowest average TOTC ($743.45). The weighted mean per diem total cost (DTOC) of the study hospitals for Medicare patients during the sutdy years was $107.98 with a standard deviation of $15.18. The hospital with the highest average DTOC ($147.23) was 1.87 times more expensive than the hospital with the lowest average DTOC ($78.49). 3. The linear models for each of the six types of hospital costs were formulated using the casemix index and the eight other hospital variables as the determinants. These models explained variance to the extent of 68.7 percent of total case cost (TOTC), 63.5 percent of room and board cost (RMC), 66.2 percent of total ancillary service cost (TANC), 66.3 percent of per diem total cost (DTOC), 56.9 percent of per diem room and board cost (DRMC), and 65.5 percent of per diem ancillary service cost (DTANC). The casemix index alone explained approximately one half of interhospital cost variation: 59.1 percent for TOTC and 44.3 percent for DTOC. Thsee results demonstrate that the casemix index is the most importand determinant of interhospital cost variation Future research and policy implications in regard to the results of this study is envisioned in the following three areas: 1. Utilization of casemix related indices in the Medicare data systems. 2. Refinement of data for hospital cost evaluation. 3. Development of a system for reimbursement and cost control in hospitals.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.155-158
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• 2010

Purpose: $^{99m}Tc$-macroaggregated albumin (MAA) hepatic arterial perfusion scintigraphy was known for useful method to evaluate patients receiving intraarterial chemotherapy for liver cancer. This study evaluate about usefulness of normal liver on hepatocellular carcinoma (HCC) from HCC patients. This study is to see the usefullness of Hepatic Arterial Perfusion Scintigraphy (HAPS) by measuring mass size, shape, lung shunting and tumor to normal ratio (T/N ratio) in relative blood stream of HCC patients compared with HCC on normal liver. Materials and Methods: From June 2009 to September 2009, HAPS studies were performed on 7 patients (men 6, women 1, mean 64) who were diagnosed HCC. HAPS was performed after proper hepatic artery $^{99m}Tc$-MAA of 5 mCi (185 MBq) injection by catheter. We performed anterior, posterior, both lateral view, SPECT of chest and abdomen. Then we set up ROI and calculated lung shunting, T/N ratio for each count, count/pixel (mean value). Results: Tumor and liver size analyzed by ROI of anterior, posterior view are 2.0-10.8 cm (mean 3.75 cm), 8.8-18.5 cm (mean 14.6 cm). T/N ratio analyzed by total tumor and total normal mean value are 2.41-5.76 (mean 3.8). lung shunting analyzed by total liver count is 3.14-13.92% (mean 6.77%). Conclusion: HAPS with $^{99m}Tc$-MAA can evaluate mass size, location, quantitative analysis through T/N ratio. also HAPS can evaluate detection of arteriovenous shunt through lung uptake before radioisotope therapy. Therefore HAPS with $^{99m}Tc$-MAA can be useful method in aspect of evaluation and treatment of HCC.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.243-247
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• 2006

$\underline{Purpose}$: To evaluate the treatment results and prognostic factors of palliative radiation therapy in the patients with unresectable advanced pancreatic cancer. $\underline{Materials\;&\;Methods$: Thirty-seven evaluable patients with unresectable advanced pancreatic cancer who were treated by palliative radiation therapy for pain relief at the Department of Radiation Oncology, Kangnam St. Mary's hospital, the Catholic University of Korea between March 1984 and February 2005 were analysed retrospectively. There were 22 men and 15 women. Age at diagnosis ranged from 30 to 80 (median 57) years. Twelve patients (32.4%) had liver metastases and 22 patients (59.5%) had lymph node metastases. Radiation therapy was delivered to primary tumor and regional lymph nodes with $1{\sim}2\;cm$ margin, and total dose was $3,240{\sim}5,580\;cGy$ (median 5,040 cGy). Chemotherapy with radiotherapy was delivered in 30 patients (81%) with 5-FU alone (21 patients) or gemcitabine (9 patients). The follow-up period ranged from 1 to 44 months. Survival and prognostic factors were analysed using Kaplan-Meier method and log-rank test respectively. $\underline{Results}$: Overall mean and median survival were 11 and 8 months and 1-year survival rate was 20%. Among 33 patients who were amenable for response evaluation, 7 patients had good response and 22 patients had fair response with overall response rate of 87.9%. Mild to moderate toxicity were observed in 14 patients with nausea, vomiting, and indigestion, but severe toxicity requiring interruption of treatment were not observed. Chemotherapy didn't influence the survival and symptomatic palliation, but the group containing gemcitabine showed a tendency of longer survival (median 12 months) than 5-FU alone group (median 5.5 months) without statistical significance (p>0.05). The significant prognostic factors were Karnofsky performance status and liver metastasis (p<0.05). Age, sex, tumor location, lymph node metastasis, and CA 19-9 level did not show any prognostic significance (p>0.05). $\underline{Conclusion}$: Radiation therapy was effective for symptomatic palliation in the patients with unresectable advanced pancreatic cancer and would play an important part in the survival benefit with gemcitabine or other targeted agents.

• Journal of Chest Surgery
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• v.30 no.2
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• pp.179-186
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• 1997

The frequency of primary lung cancer is increasing compared to other cancer. Complete surgical resection is the most effective method of treatment, but it is limited to only 25 to 30 percent of patients after initial clinical presentation. The survival rate is different by the subtypes of carcinoma, stages, and general condition of patients. The author investigated the survival rate of 87 patients with squamous cell carcinoma of the lung after surgery. Age ranged from 31 to 73 years, with Lean 57.1) $\pm$ 7.15 and 80.5% (70 cases) was initially diagnosed at sixth and seventh decades. Male to female ratio was 8.9'1. Initial complaints were cough with sputum in 78.1%, weight loss in 31.0%, chest pain and discomfort in 29.9%, and hemoptysis in 24.1%. The location of the tumor was right side in 44.8% and left slde in 55.2% ; LUL in 39.1%, RLL in 20.7%, LLL in'16. 1%, RUL in 14.9% and RML in 9.2%. Stage I was 19.5%, stage II 25.3%, stage olla 54.1% and stage lIIb 1.1%. Operative procedures were as follow : pneumonectomy in 52.9%, lobectomy in 47.1%, sleeve upper lobectomy in 4 cases. Single mediastinal Iymph node involvement was observed in 17 cases, and multi-level mediastinal Iymph node involvement in 23 cases. Lower paratracheal Iymph node and subcarinal Lymph node were more frequently involved in right side lung cancer, with 8 and 10 cases, respectively and subaortic Iymph node was most frequently involved in left side lung cancer with 9 cases. Operative complications were hoarseness, wound infection and chylothorax in 7, 5 and 4 cases, respectively. The operative mortality was 2.2% and the cause of death was pulmonary edema. Postoperative follow-up period ranged from 1 month to 99 months with a mean of 29.95 $\pm$ 17.21 months. Overall one-year survival rate was 75.1 % and five-year survival rate was 29.8%. One-year and five-year survival rates were 93.7% and 52.4% for stage 1, 92.2% and 30.5% for st ge ll, and 61.2% and 17.4% for stage llla, respectively. These findings correlate survival rate with tumor size, mediastinal Iymph node metastasis and surgical resectability, and long-term survival can be expected with small sized tumor, absent mediastinal Iymph node metastasis and complete surgical resection.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.168-177
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• 2001

Sanitary management practices were assessed to insure the safety of school foodservice, to prevent the outbreak of foodborne illness, and to improve the quality of school foodservice. To accomplish these objectives, a survey was conducted and analyzed on elementary and high school foodservice operations located in Seoul area. A Questionnaire from based on HACCP standards was developed and used for self-reported evaluation of the school foodservice managers on their sanitary management practices. The results were analysed by examining their activities and identifying weaknesses in those activities. The questionnaire was composed of three sectors with all 53 questions; 33 questions for time-temperature management, 5 for personal hygiene and 15 for equipment/facility sanitation. Five-point-scale was used on the questionnaire answers. Among the schools responded,253 (98.4% of the total) were elementary schools and 19 (1.6%) were high schools. Among the three sectors, personal hygiene performance was mostly well conducted by marking average 4.06$\pm$0.57. Equipment/facility sanitation came next by marking average 3.84$\pm$0.53. Time-temperature marked average 3.45$\pm$0.46. “Storage after cooking (2.03$\pm$0.94)”was identified as the least managed activities because the school foodservice operations were not equipped well with hot holding and/or cold holding. “Separate use of sink per usage (3.03$\pm$1.10)” and “proper location of hand washing facility (3.07$\pm$1.13))” were identified as the least practiced activities in equipment/facility sanitation sector. To enhance these practices, proper number of sinks and hand washing facilities should be equipped first within the kitchen area.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.611-621
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• 2001

Objective : We analyzed the clinical and endocrinological results of the transsphenoidal microsurgery for ACTH secreting pituitary adenomas. Marerials and Methods : From October 1995 to August 2000, 18 patients underwent transsphenoidal microsurgery for Cushing's disease. We analyzed the surgical results of 17 patients, one patient who was previously operated from other hospital was excluded. Age of the patients were 18 to 61 years old(mean 37.7), male to female ratio was 1 : 3.3, and follow-up period was 3 to 50 months(mean 20.3). The selection of candidates for transsphenoidal exploration was based on endocrinologic criteria. Magnetic resonance imaging was the preferred radiologic test. Selective inferior petrosal sinus sampling of adrenocorticotropic hormone futher refined the diagnosis when endocrinologic and radiologic procedures were not definitive. Results : Results of the preoperative endocrinological test were : level of serum ACTH 29.4 to $225{\mu}g/dL$(mean $93.88{\mu}g/dL$) ; serum cortisol 11.9 to $47.5{\mu}g/dL$(mean $27.49{\mu}g/dL$) ; 24-hour urine free cortisol 235 to $1019{\mu}g/day$(mean $571.0{\mu}g/day$). Inferior petrosal sinus sampling for ACTH was performed in 11 patients and all were confirmed by Cushing's disease and we could predict the laterality of the tumor in 9 of 11 patients. We performed transsphenoidal selective adenomectomy in 5 patients, adenomectomy and subtotal hypophysectomy in 2 patients, adenomectomy and partial hypophysectomy in 9 patients, and in the remaining one patient, hemihypophysectomy followed by total hypophysectomy due to remission failure. Fifteen of 17 patients(88.2%) showed endocrinological remission. Glucocorticoid replacement therapy was performed in all the patients who showed remission for 1 to 24 months(mean 5.9 months), and 6 patients received steroid over 6 months. Conclusion : We conclude that the direct demonstration of a tumor in the pituitary gland by MRI is the most important and definitive diagnostic tool and the location of a mass should be confirmed with increased level of ACTH by the inferior petrosal sinus sampling. Transsphenoidal microsurgery is effective treatment modality for Cushing's disease and the immediate postoperative evaluation of the surgical resection of the tumor is very important. The patients should show hypocortisolism, decreased, subnormal serum ACTH and cortisol levels and 24-hours urine free cortisol. We performed 18 transsphenoidal microsurgery for Cushing's disease in 17 patients and 15 patients(88.2%) showed endocrinological remission.