• Progress in Medical Physics
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• v.20 no.4
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• pp.260-268
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• 2009

In this study, we estimated inhomogeneity correction factor in small field. And, we evaluated accuracy of treatment planning and measurement data which applied inhomogeneity correction factor or not. We developed the Inhomogeneity Correction Phantom (ICP) for insertion of inhomogeneity materials. The inhomogeneity materials were 12 types in each different electron density. This phantom is able to adapt the EBT film and 0.125 cc ion chamber for measurement of dose distribution and point dose. We evaluated comparison of planning and measurement data using ICP. When we applied to inhomogeneity correction factor or not, the average difference was 1.63% and 10.05% in each plan and film measurement data. And, the average difference of dose distribution was 10.09% in each measurement film. And the average difference of point dose was 0.43% and 2.09% in each plan and measurement data. In conclusion, if we did not apply the inhomogeneity correction factor in small field, it shows more great difference in measurement data. The planning system using this study shows good result for correction of inhomogeneity materials. In radiosurgery using small field, we should be correct the inhomogeneity correction factor, more exactly.

• Progress in Medical Physics
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• v.20 no.4
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• pp.324-330
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• 2009

In this study, we evaluated accuracy and usefulness of CyberKnife Respiratory Tracking System ($Synchrony^{TM}$, Accuray, USA) about a moving during stereotactic radiosurgery. For this study, we used moving phantom that can move the target. We also used Respiratory Tracking System called Synchrony of the Cyberknife in order to track the moving target. For treatment planning of the moving target, we obtained an image using 4D-CT. To measure dose distribution and point dose at the moving target, ion chamber (0.62 cc) and gafchromic EBT film were used. We compared dose distribution (80% isodose line of prescription dose) of static target to that of moving target in order to evaluate the accuracy of Respiratory Tracking System. We also measured the point dose at the target. The mean difference of synchronization for TLS (target localization system) and Synchrony were $11.5{\pm}3.09\;mm$ for desynchronization and $0.14{\pm}0.08\;mm$ for synchronization. The mean difference between static target plan and moving target plan using 4D CT images was $0.18{\pm}0.06\;mm$. And, the accuracy of Respiratory Tracking System was less 1 mm. Estimation of usefulness in Respiratory Tracking System was $17.39{\pm}0.14\;mm$ for inactivity and $1.37{\pm}0.11\;mm$ for activity. The mean difference of absolute dose was $0.68{\pm}0.38%$ in static target and $1.31{\pm}0.81%$ in moving target. As a conclusion, when we treat about the moving target, we consider that it is important to use 4D-CT and the Respiratory Tracking System. In this study, we confirmed the accuracy and usefulness of Respiratory Tracking System in the Cyberknife.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.131-141
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• 2001

Purpose: We evaluated the sensitivity of the F-18 FDG PET by visual assessment and statistical parametric mapping (SPM) analysis for the localization of the epileptogenic zones in frontal lobe epilepsy. Materials and Methods: Twenty-four patients with frontal lobe epilepsy were examined. All patients exhibited improvements after surgical resection (Engel class I or II). Upon pathological examination, 18 patients revealed cortical dysplasia, 4 patients revealed tumor, and 2 patients revealed cortical scar. The hypometabolic lesions were found in F-18 FDG PET by visual assessment and SPM analysis. On SPM analysis, cutoff threshold was changed. Results: MRI showed structural lesions in 12 patients and normal results in the remaining 12. F-18 FDG PET correctly localized epileptogenic zones in 13 patients (54%) by visual assessment. Sensitivity of F-18 FDG PET in MR-negative patients (50%) was similar to that in MR-positive patients (67%). On SPM analysis, sensitivity decreased according to the decrease of p value. Using uncorrected p value of 0.05 as threshold, sensitivity of SPM analysis was 53%, which was not statistically different from that of visual assessment. Conclusion: F-18 FDG PET was sensitive in finding epileptogenic zones by revealing hypometabolic areas even in MR-negative patients with frontal lobe epilepsy as well as in MR-positive patients. SPM analysis showed comparable sensitivity to visual assessment and could be used as an aid in the diagnosis of epileptogenic zones in frontal lobe epilepsy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4863-4872
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• 2010

This study examined the disease conditions of patients from a farming and fishing village area. In order to analyze the medical service utilization, the necessary data were obtained from established health and medical care service plans from medical treatment related organizations. The following results were based on the analysis of data from the medical records of 2,365 discharged patients during a six months period from July to December 2009 at a general hospital in an aging farming and fishing village area. Results: The sex of the patients investigated was male 55.3%, female 44.7%, and the most frequent age category at 42.0% was 70 years of age or older. Based on type of hospital admission, 65.5% of patients who were admitted were originally outpatients. Patients were admitted according to the following departments: 49.7% for the department of internal medicine, 16.7% for the department of orthopedics, and 13.8% for the department of neurosurgery. The average number of days hospitalized was 14.8 days. The following ranks the principal diagnosis among patients in this study: S00-T98 18.4%, J00-J99 15.5%, and I00-I99 11.5%. The average number of diagnosis listed per patient was 5.6. There was a statistically significant difference for the following general characteristics according to principal diagnosis list: gender, type of insurance, admission process, and age category distribution had statistically significant differences. Monthly distribution of principal diagnoses were statistically significant difference. There was a statistically significant difference for principal diagnosis lists according to the average number of days admitted and the number of diagnosis. The results of this study showed the types of disease from typical farming and fishing village regions as disease from external injury due to the work environment of farming and fishing village regions and excessive labor throughout the year, respiratory disease, and various chronic disease from aging.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.183-194
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• 1988

Twenty five patients with histologically proven medulloblastoma received craniospinal radiotherapy (CSRT) at the Seoul National University Hospital from 1979 to 1984. The extent of tumor removal was biopsy only in 2 patients, partial in 18, and near total in 5. With orthogonal technique of CSRT, mainly 55Gy was delivered to the posterior fossa (PF), 40Gy to whole brain (WB), and 30Gy to whole spine (WS). And with AP; PA technique, 50Gy to PF, 45-50Gy to WB, and 36 Gy to WS. Complete remission was obtained in $84\%$ of patients. Among 21 CR's 10 failures were observed, thus total failure rate was $56\%$ (14/25). Of 14 faiure 13 had the primary failure, 11 failed in primary site alone, 1 failure was combined with ventricular seeding, and another 1 was combined with neck node metastasis. There was 1 isolated spinal failure. Actuarial overall survival rates at 3 and 5 years were $75\%$ and $54\%$, and disease-free survival rates were $58\%$ and $36\%$, respectively. Better 5 year disease-free survival was noted in patients with 55 Gy to the posterior fossa than those with 50Gy $(62\%\;vs\;17\%,\;p<0.05)$, in patients treated with orthogonal technique than those treated with AP:PA technique $(87\%\;vs\;12\%,\;p<0.05)$, and in patients with near total removal than those with partial or less removal of tumor $(56\%\;vs\;30\%,\;N.S.)$ Re-irradiation was not satisfactory No severe late sequelae was noted among the survivors. For the higher control of medulloblastoma, dose to posterior fossa should be at least 55Gy with orthogonal CSRT to small tumor burden. And dose reduction in the subarachnoidal spaces might be safe, but optimal dose to the subarchnoidal spaces should be determined by the thorough tumor staging before radiotherapy.

• Korean Journal of Psychosomatic Medicine
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• v.12 no.1
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• pp.15-22
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• 2004

Objectives: Delirium after head trauma results in various cognitive and behavioral dysfunction. This study aimed at developing and validating a predicitive model for clinical improvement after delirium based on precipitating factors during hospitalization Method: Data were collected on 45 patients who developed delirium after head trauma using 5 year retrospective design, based on reviews of medical charts including psychiatric consultation reports. The differences of the group who sustained residual symptoms of delirium(The RS group) and the group of full recovery(The FR group) at 4 week follow-up visits were compared by motoric type of delirium, socio-demographic variables, neuroimaging variables and clinical variables of interest. Result: There was significant difference in reason for initial consultation between two groups, in terms of hyperactivity(p<.01). The presence of compensation claim, subcortical gray matter lesion was significantly associated with the RS group(p<.05). Total length of intensive care unit(ICU) admission and of hospital stay were significantly longer in RS group than FR group(p<.01). Conclusion: This study shows that hyperactivity on initial consultation, compensation claims, specific brain lesion were altogether significant factors in explaining prolonged duration of delirium after head trauma. A simple predictive model based on the presence of precipitating factors might be used to identify delirious patients at high risk for prolonged cognitive dysfunction. Early psychiatric intervention would be required for evaluating efficacious management and shortening admission period.

• The Korean Journal of Pharmacology
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• v.19 no.1
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• pp.123-131
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• 1983

1) To delineate the role of central ${\alpha}_2-adrenoceptors$ in the pressor response to raised intracranial pressure(ICP), the influence of yohimbine, an ${alpha}_2-adrenoceptor$ antagonist, on the pressor response to raised ICP was investigated in urethane-anesthetized rabbits. 2) The ICP was raised by infusing saline into a balloon placed in the epidural space. The rise of ICP was slow in the beginning of the infusion but it became sharp as the infusion proceeded. 3) In response to raised ICP, blood pressure(BP) tended to decrease slightly in the beginning and then increased sharply. BP, however, fell abruptly and markedly if ICP was raised further. The maximal pressor response to raised ICP was the increase of $49{\pm}2.4%$ of the original $BP(mean{\pm}SE\;in\;32\;experiments)$, and at this point the volume of saline infused into the balloon was $1.22{\pm}0.15\;ml$, and the ICP $165{\pm}6.4\;mmHg$. 4) Intraventricular yohimbine $(50{\mu}g)$ by itself did not affect BP. After the administration of this dose of yohimbine the increase of both ICP and BP was observed after the infusion of much smaller volume of saline than in the control animals, i.e., after the infusion of $0.83{\pm}0.02\;ml$ of saline the maximal increase of preesor response$(57{\pm}4.5%\;in\;6\;experiments)$ appeared and at this state the ICP was $164{\pm}9.6\;mmHg$. 5) Intraventricular $clonidine(30{\mu}g)$ markedly decreased BP by itself, and in the clonidine-treated rabbits the increase of ICP induced by the infusion was much less than in the control group and the pressor response to raised ICP was hardly seen. 6) The hypotensive effect of intraventricular clonidine was reversed by a susequent intraventricular $yohimbine(500\;{\mu}g)$. At this state the pressor response to raised ICP appeared as in the control animals. 7) These results show that the pressor response to raised ICP was facilitated when ${\alpha}_2-adrenoceptors$ in the rabbit brain was blocked by yohimbine and that yohimbine antagonized the inhibitory effect of clonidine on the pressor response to raised ICP.

• The Korean Nurse
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• v.35 no.2
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• pp.71-91
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• 1996

The objectives of thes study were to identify the need for equipment development in nursing, and to determine the priorities for that development. The study was descriptive study done between March 2 and May 30, 1995, in which the subjects, including 421 patients, 223 family members, and 198 nurses from neurosurgery, orthopedic, rehabilitation medicine, internal medicine and intensive care units of nine general hospitals in Seoul, completed a questionnarie developed by the research team. The questionnaire consisted of 35 open and closed questions. Data was analyzed using frequencies and percentages. The results ware summarized as follows: 1) The average age of the nurses was 27.9 years, 48% of the patients were between 20 and 40 years of age, and 17% were over 60. The average lingth of experience for the nurse subjects was four years five months with 36.9%. having over five years experience. The most frequent diagnoses of patients were spinal disc(35.9%), internal medicine disease(26.0%), cerebral vascular accident(16.6%) and spinal cord injury(10%) 2) Many of the nurses(96.4%) reported deficiencies with existing equipment and 96.5% of the nurses, but only 79.8% of the patients, nurses' time. Further, 82.3% of the nurses and 75.8% of the patients felt that the development of new equipment would lead to a decrease in the cost of nursing care. 3) Nurses felt that the greatest areas of inconvenience were patient feeding(71.7%), hygiene(71.2%), caring for a patient confined to bed(70.7%), patient clothing(67.2%), mobility transfers(63.5%) and urinary elimination(52.0%). However, patients and family members listed the following as being the most inconvenient: urinary elimination(58.7%), Hygiene(50.5), feeding(48.4%), mobility transfers(47.1%) and bed care(45.2%). 4) Generally the nurses listed more inconveniences and patients and family members listed more demands for the development of equipment. These included utensils with large handles, and regulators for tube feedings; mattresses that provide for automatic position change and massage, which have patient controlled levers and a place for bed pan insertion; automatic lifts or transfer from bed to wheelchair; equipment to facilitate washing and oral hygiene as well as equipment that will allow patients with spinal cord injuries easy access to showers; a bed pan/urinal for women that is comfortable and effective from which urine can be measured and disposed of easily; disposable dressing sets and tracheostomy care sets and a convenient way of measuring changes in wound size; a safe delivery system for oxygen, a variety of mask sizes and better control of humidity, tracheal material than at present, as well as a communication system for patients with tracheostomies; clothing that will allow access to various parts of the body for treament or assessment without patients having to remove all of their clothing; and finally a system that will allow the patient to control lighting, telephones and pagers. Priority areas for equipment development reported by the nurses were, urinary elimination(58. 7%), hygiene(50.5%), feeding(48.4%), mobility transfers(47..1%), bowel elimination(40.8%). Those reported by the patients family members were feeding(71.7%), hygiene(70.0%), bedcare(70.7%), clothing(67.2%), mobility transfers(63.6%), urinary elimination(52.9%) and bowel elimination(50.5%) Altogether, nurses, patients and family members listed the following as priorities; clothing (178), bed care(144), urinary elimination(92), environment(81), hygiene(70). Further, a health professional forum listed urinary elimination, oxygen delivery, medication delivery, mobility transfers, bed care and hygiene in that order as priority areas. From this study it can be concluded that the first need is to develop equipment that will address the problems of urinary elimination. To do (l)This nurses who are interested in equipment development should organize an equipment development team to provide a forum for discussion and production of equipment for nursing.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.1-9
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• 2003

Purpose : The purpose of this study was to analyze the effect of a Linear accelerator based Photon Knife Radiosurgery System developed by the staff of Keimyung University Dongsan Medical Center for the treatment of cerebral arterlovenous malformation Material and Methods : Between December 1993 and October 2000, 30 patients with cerebral arteriovenous malformation (AVM) were treated with the Linac based Photon knife Radlosurgery System In the Department of Therapeutlc Radiology at Keimyung University Dongsan Medical Center. The median age was 34, ranging from 7 to 63 years, with a 2 : 1 male to female ratio. The locations of the AVM nidi were the frontal lobe (motor cortex), parletal lobe, and the thalamus, In that order. The diameters of the AVM nidi ranged 1.2 to 5.5 cm with a mean on 2.9 cm, and target volumes of between 0.5 and 20.5 cc, with a mean of 5.8 cc. The majority of patients received radiation doses of between 1,500 and 2,500 cGy, w14h a mean of 2,000 cGy, at 80% the isodose line. Twenty-five patients were treated with one isocenter, 4 with two, and 1 with four. The follow-up radiological evaluations were peformed with cranial computed tomogram (CT) or MRI between 6 month and one year interval, and if the AVM nidus had completely disappeared in the CT or MRI, we confirmed thls was a complete obliteration, with a cerebral or magnetic resonance angiogram (MRA). The median iollow-up period was 39 months with a range of 10 to 103 months. Results : Twenty patients were radloiogicaiiy followed up ior over 20 months, with complete obliteration observed in 14 (70%). According to the maximal diameter, all four of the small AVM (<2 cm) completely obliterated, 8 of the 10 patients with a medium AVW (2~3 cm) showed a complete obliteration, and two showed partial obliteration. Among the patients with a large AVM (>3 cm), only one showed complete obliteration, and S showed partial obliteration, but 3 oT these underwent further radiosurgery 3 years later. One who followed up for 20 months fellowing further radiosurgery eventually showed complete obliteration. Ten patients with seizure symptoms had no recurrent seizure due to radiosurgery and medication. One of the eleven patients who suffered intracranlal bleeding developed further bleeding at 9 and 51 months fellowing the radiosurgery although complete obliteration was eventually observed and the patient was managed in hospital then recovered. No patient suffered severe complications fellowing the radiosurgery. Conclusion : The radiosurgery with Linac-based Photon knife radiosurgery system, developed by the staff at our hospital, is a safe and effective treatment for AVM patients having diameters or volumes of less than 3 cm or 10 cm$^{3}$, respectively, located In Inoperable areas or who refused neurosurgery. We suggest that staged AVM radiosurgery may initially be considered, if the AVM target volume is above 10 cm$^{3}$

• Radiation Oncology Journal
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• v.21 no.1
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• pp.94-99
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• 2003

Purpose : To explore a 3D conformal radiotherapy technique for a posterior fossa boost, and the potential advantages of a prone position for such radiotherapy. Materials and Methods :A CT simulator and 3D conformal radiotherapy Planning system was used for the posterior fossa boost treatment on a 13-year-old medulloblastoma patient. He was placed In the prone position and Immobilized with an aquaplast mask and immobilization mold. CT scans were obtained of the brain from the top of the skull to the lower neck, with IV contrast enhancement. The target volume and normal structures were delineated on each slice, with treatment planning peformed using non-coplanar conformal beams. Results : The CT scans, and treatment In the prone position, were peformed successfully. In the prone position, the definition of the target volume was made easier due to the well enhanced tentorium, In audition, the posterior fossa was located anteriorly, and with the greater choice of beam arrangements, more accurate treatment planning was possible as the primary beams were not obstructed by the treatment table. Conclusion : .A posterior fossa boost, in the prone position, Is feasible in cooperating patients, but further evaluation is needed to define the optimal and most comfortable treatment positions.