• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.826-831
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• 2000

The major indication of endoscope in neurosurgical field is intraventricular procedures. Recently, it can be used selectively in the intraaxial mass lesion associated cavity. For example, cystic mass, with liquefied necrosis, and blood clot can be approached with this technique. The authors present its usage in brain abscess ruptured into lateral ventricle. The neuroendoscope was introduced into abscess cavity through stereotactic guidance, the pus was then removed through continuous irrigation and suction under direct video visualization. The intraventricular pus was also cleaned through gentle, direct endoscopic irrigation and suction. The postoperative clinical course was uneventful. Brief overview is given for this intraaxial neuroendoscopic procedure.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.51-56
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• 2006

이 연구에서는 의료서비스 품질 향상을 위하여 제안된 뇌 전위적 영상안내에 의한 개두술 방법과 옥틸 시안화 아크렬산염 (2-octylcyanoacrylate: 2-0CA)을 드레싱 재료로 사용한 조사군과, 전통적 개두술 방법과 봉합사 및 아이오다인을 사용했던 대조군과 비교를 실시하여 의료품질 향상 효과를 분석하였다. 연구방법으로는 특정 의료기관에서 26 례 조사군과, 38례 대조군을 대상으로, 임상적 특성, 감염균, 두피접착의 열개(裂開)성 및 기타 위험 인자를 조사하였다. 연구결과 새롭게 제안된 의료용 재료인 2옥틸시안화 아크릴산염은 피부조직 속으로 외부 액체가 유입되는 것을 억제하거나 제한하였으며, 외피 접착기능으로 창상보호 특히, 평균감염률과 감염빈도에 있어서 상대적으로 대조군보다 우수하였다. 한편 뇌 전위적 영상 안내에 의한 개두술 방법으로 수술시간의 단축과 수술 복잡성의 경감 및 위험성이 감소되었으며, 상처 부위 흔적이 적게 남는 등 미용적인 측면에서도 우수한 것으로 나타났다.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.141-145
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• 1988

A patient of cerebral sparganosis is reported : The patient, a 47-year-old female complained of frequent seizures and headache. The disease was involved on right frontal lobe, and the lesion was successfully removed by BRW stereotaxic system. The characteristic features of sparganosis are reviewed.

• Journal of the Korean Society of Radiology
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• v.8 no.7
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• pp.389-395
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• 2014

The research was carried out to develop a animal model of malignant brain tumor for the researches in glioblastoma multiform (GBM) diagnosis and therapy. C6 cells were transplanted into the right striatum of SD rat using stereotactic instrument for the development. The developed animal model was verified by MRI and H&E stain assay of anatomicohistological examination. The MRI observations showed that the tumor developed at the injection site at the 7 days after glioblastoma inoculation. At 14 days post inoculation, the tumor grew to a large volume occupying almost a half of the right cerebral hemisphere. It was confirmed that the expression of excessive mitosis and pleomorphism in anatomicohistological examination. The developed animal model must be necessary and useful tool for the in vivo level research in the development of the new modality for the diagnosis and therapy of brain cancer.

• Progress in Medical Physics
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• v.23 no.4
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• pp.303-308
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• 2012

The Geant4 based Monte Carlo code for the application of stereotactic radiosurgery was developed. The probability density function and cumulative density function to determine the incident photon energy were calculated from pre-calculated energy spectrum for the linac by multiplying the weighting factors corresponding to the energy bins. The messenger class to transfer the various MLC fields generated by the planning system was used. The rotation matrix of rotateX and rotateY were used for simulating gantry and table rotation respectively. We construct accelerator world and phantom world in the main world coordinate to rotate accelerator and phantom world independently. We used dicomHandler class object to convert from the dicom binary file to the text file which contains the matrix number, pixel size, pixel's HU, bit size, padding value and high bits order. We reconstruct this class object to work fine. We also reconstruct the PrimaryGeneratorAction class to speed up the calculation time. because of the huge calculation time we discard search process of the ThitsMap and used direct access method from the first to the last element to produce the result files.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.351-359
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• 1991

The current LINAC technique for radiosurgery utilizes a single isocenter approach with multiple noncoplanar arcs. This approach results in spherical dose distributions in the target. Many arteriovenous malformations and tumors suitable for radiosurgical treatment have non-spherical or irregular shapes. The basic approach presented in this paper is to use two or multiple isocenters with standard arcs to shape irregular target volumes through the use of multiple spherical targets. Selection of reasonable irradiation parameters in the first stage is critical to the success of real-time optimization. A useful guideline for optimum isocenter separation and collimator size is developed to shape the target margin uniformly with an desired isodose surface for an elongated target. The implementation of multiple isocenters with three dimensional dose model and application of multiple isocenters approach to several cases are discussed.

• Progress in Medical Physics
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• v.5 no.2
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• pp.57-68
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• 1994

Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.241-247
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• 1993

Between July 1988 and December 1992, we treated 45 patients who had deep seated inoperable or residual and/or recurrent intracranial tumors using LINAC based stereotactic radiosurgery at the Department of Therapeutic Radiology, Kangnam St. Mary's Hospital, Catholic University Medical College. Treated intracranial tumors included pituitary tumors (n=15), acoustic neurinomas (n=8), meningiomas (n=7), gliomas (n=6), craniopharyngiomas (n=4), pinealomas (n=3), hemangioblastomas (n=2), and solitary metastatic tumor from lung cancer (n=1). The dimension of treatment field varied from 0.23 to 42.88 $cm^3\;(mean;\;7.26\;cm^3)$. The maximum tumor doses ranging from 5 to 35.5 Gy (mean; 29.9 Gy) were given, and depended on patients' age, target volume, location of lesion and previous history of irradiation. There were 22 male and 23 female patients. The age was varied from 5 to 74 years of age (a median age; 43 years). The mean duration of follow-up was 35 months (2~55 months). To date, 18 $(39.1\%)$ of 46 intracranial tumors treated with SRS showed absent or decrease of the tumor by serial follow-up CT and/or MRI and 16 $(34.8\%)$ were stationary, e.g. growth arrest. From the view point of the clinical aspects, 34 $(73.9\%)$ of 46 tumors were considered improved status, that is, alive with no evidence of active tumor and 8 $(17.4\%)$ of them were stable, alive with disease but no deterioration as compared with before SRS. Although there showed slight increase of the tumor in size according to follow-up imagings of 4 cases (pituitary tumor 1, acoustic neurinomas 2, pinealoma 1), they still represented clinically stable status. Clinically, two $(4.4\%)$ Patients who were anaplastic astrocytoma (n=1) and metastatic brain tumor (n=1) were worsened following SRS treatment. So far, no serious complications were found after treatment. The minor degree headache which could be relieved by steroid or analgesics and transient focal hair loss were observed in a few cases. There should be meticulous long term follow-up inall cases.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.1
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• pp.27-33
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• 2007

Purpose: We have performed SRS (stereotactic radiosurgery) for avm (arterry vein malformation) and brain cancer. In order to verify dose and localization of SRS, dose distributions from TPS ($X-Knife^{(R)}$ 3.0, Radionics, USA) and GafChromic $EBT^{(R)}$ film in a head phantom were compared. Materials and Methods: In this study, head and neck region of conventional humanoid phantom was modified by substituting one of 2.5 cm slap with five 0.5 cm acrylic plates to stack the GafChromic $EBT^{(R)}$ film slice by slice with 5 mm intervals. Four films and five acrylic plates were cut along the contour of head phantom in axial plane. The head phantom was fixed with SRS head ring and adapted SRS localizer as same as real SRS procedure. CT images of the head phantom were acquired in 5 mm slice intervals as film interval. Five arc 6 MV photon beams using the SRS cone with 2 cm diameter were delivered 300 cGy to the target in the phantom. Ten small pieces of the film were exposed to 0, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 cGy, respectively to calibrate the GafChromic $EBT^{(R)}$ film. The films in the phantom were digitized after 24 hours and its linearity was calibrated. The pixel values of the film were converted to the dose and compared with the dose distribution from the TPS calculation. Results: Calibration curve for the GafChromic $EBT^{(R)}$ film was linear up to 900 cGy. The R2 value was better than 0.992. Discrepancy between calculated from $X-Knife^{(R)}$ 3.0 and measured dose distributions with the film was less than 5% through all slices. Conclusion: It was possible to evaluate every slice of humanoid phantom by stacking the GafChromic EBT film which is suitable for 2 dimensional dosimetry, It was found that film dosimetry using the GafChromic $EBT^{(R)}$ film is feasible for routine dosimetric QA of stereotactic radiosurgery.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.199-204
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• 2001

Purpoe : To find the optimal values of total arc degree to protect the normal brain tissue from high dose radiation in stereotactic radiotherapy planning. Methods and Materials : With Xknife-3 planning system & 4 MV linear accelerator, the authors planned under various values of parameters. One isocenter, 12, 20, 30, 40, 50, and 60 mm of collimator diameters, $100^{\circ},\;200^{\circ},\;300^{\circ},\;400^{\circ}C,\;500^{\circ},\;600^{\circ}$ or total arc degrees, and $30^{\circ}\;or\;45^{\circ}$ or arc intervals were used. After the completion of planning, the plans were compared each other using $V_{50}$ (the volume of normal brain that is delivered high dose radiation) and integral biologically effective dose. Results : At $30^{\circ}$ of arc interval, the values of $V_{50}$ had the decreased pattern with the increase of total arc degree in any collimator diameter. At 45 arc interval, up to $400^{\circ}$ of total arc degree, the values of $ V_{50}$ decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. At $30^{\circ}$ of arc interval, integral biologically effective dose showed the decreased pattern with the increase of total arc degree in any collimator diameter. At $45^{\circ}$ arc interval with less than 40 mm collimator diameter, the integral biologically effective dose decreased with the increase of total arc degree, but with n and n mm or collimator diameters, up to $400^{\circ}$ or total arc degree, integral biologically effective dose decreased with the increase of total arc degree, but at $500^{\circ}\;and\;600^{\circ}$ of total arc degrees, the values increased. Conclusion : In the stereotactic radiotherapy planning for brain lesions, planning with $400^{\circ}$ of total arc degree is optimal. Especially, when the larger collimator more than 50 mm diameter should be used, the uses of $500^{\circ}\;and\;600^{\circ}$ of total arc degrees make the increase of$V_{50}$ and integral biologically effective dose. Therefore stereotactic radiotherapy planning using $400^{\circ}$ of total arc degree can increase the therapeutic ratio and produce the effective outcome in the management of personal and mechanical sources in radiotherapy department.