• Progress in Medical Physics
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• v.15 no.4
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• pp.197-201
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• 2004

Stereotactic brain biopsy using stereotactic head frame such as CRW (Radionics, USA) has demonstrated a precise lesion localizing accuracy. In this study, we developed the target point calculation program for brain lesion biopsy using CRW stereotactic head frame and designed a phantom for verify the new developed program. The phantom was designed to have capability to simulate clinical stereotactic brain biopsy. The phantom has 10 vertical rods whose diameters are 6mm and tip of each rods are 2mm. Each rod has different length, 150 mm x 4 ea, 130 mm x 4 ea, 110 mm x 2 ea. CT images were acquired with Simens CT scanner as continuous transverse slice, 1 mm thickness in a 25 cm field of view and stored in a dicom file as a 256 x 256 matrix. As a result, the developed new target localization program will be useful for planning and training in complicated 3 dimensional stereotactic brain biopsy.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.612-614
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• 1998

뇌정위 수술(Stereotactic Surgery)은 컴퓨터 단층영상과 자기공명 영상 같은 3차원 영상을 이용하여 뇌병변의 위치를 입체적으로 정확히 파악하여 정상 뇌에 대한 손상을 최소화하며 병변을 수술하는 기법이다. 본 논문에서는 수술 받을 환자의 컴퓨터 단층영상과 자기공명 영상 등 다양한 종류의 3차원 볼륨 데이터를 전처리한 다음 동일한 3차원 공간 내에서 정렬시켜 선택적 또는 동시적으로 3차원 영상을 가시화 하는 기법을 제안한다. 또한 3차원 영상에서 뇌정위 수술의 삽입점과 목표점을 지정할 수 있는 기능을 지원하며 수술 경로에 따른 가상 수술의 시뮬레이션을 통하여 수술 경로의 안전성을 검증할 수 있게 하였다.

• Progress in Medical Physics
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• v.2 no.2
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• pp.121-128
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• 1991

Radiosurgery treatment in the brain requires detailed information on three-dimensional dose distribution. A three-dimensional treatment planning is a prerequisite for treatment plan optimization. It must cover 3-D methods for representing the patient, the dose distributions, and beam settings. Three-dimensional dose models for non-coplanar moving arcs were developed using measured single beam data and efficient 3-D dose algorithms for circular fields. The implementation of three dimensional dose algorithms with stereotactic radiosurgery and the application of the algorithms to several cases are discussed.

• Radiation Oncology Journal
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• v.10 no.1
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• pp.101-105
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• 1992

Authors performed a stereotactic radiosurgery with multiple noncoplanar convergent photon beams of linear accelerator (NELAC-1018 18 MeV, NEC) using a specially designed Yeungnam localization device for two patients with recurrent glioblastoma multiforme. One patient had 2 cm sized and the other 4 cm sized mass on the CT images. After single session of treatment with 15 and 20 Gy, headache was improved in a few days after radiosurgery with no remarkable untoward reactions. Our experience with these two patients were encouraging and we found that our localization device, which is easily adjustable and inexpensive, could be a valuable tool for stereotactic radiosurgery particularly in the treatment of recurrent brain tumor.

• Radioisotope journal
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• v.7 no.4
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• pp.24-30
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• 1992

• The Journal of Korean Society for Radiation Therapy
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• v.7 no.1
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• pp.45-53
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• 1995

목적 : 뇌정위 방사선수술은 AVM(ateriovenous malformation)이나 작은 크기의 종양에 1회에 고선량의 방사선을 조사하는 기술이다. 선형가속기를 이용한 방사선 수술을 하기 위하여 최근 본원에 설치한 Philips SL 75-5 선형가속기와 isocentric sub system(ISS)에 의한 뇌정위 방사선 수술에 있어서 표적의 위치선정과, gantry와 couch의 회전시 기하학적 오차가 중요시 되는데 isocentric sub system의 오차를 분석 하였다. 대상 및 방법 : 방사선원으로는 Philips SL 75-5 선형가속기의 5MV 광자선을 사용하였고, 원형의 작은 광자선속을 위하여 isocenter에서의 직경이 26mm인 secondary cone을 gimbal baaring에 삽입하여 사용하였다. 표적의 크기와 좌표를 정하기 위하여 CT나 angio localizer를 이용하고, 표적좌표 선정을 위하여 BRW phantom base와 target pointer를 이용하여 임의의 BRW-coordinator를 바꾸어 가면서 gantry angle와 ISS head 각도를 임의로 바꾸어 가면서 film에 방사선을 조사하였다. 흑화된 film을 view box 위에 놓고 광학판독기구로 film 가장자리의 오차를 scale 확대경으로 측정하여 오차를 분석하였다. 결과 : 표적좌표 선정의 정확도를 확인하기 위하여 임의의 표적좌표에 gantry의 10개각도 ISShead의 10개각도에서 각각 광자선을 조사시켜 film을 이용하여 오차를 측정한 결과 collimator cone의 직경이 26mm일때 전체 평균오차가 0.219+-0.03mm이었다. 결론 : Isocentric sub system은 gantry head와 ISS arm 사이에 gimbal bearing이 있어서 이 부위를 flexible하게 연결함으로 gantry의 회전에 무관하게 정확한 isocenter를 유지시켜 주고 ISS head는 couch와 독립되어 움직이므로 isocentric sub system isocenter의 오차를 최대한 줄일수 있음을 알았다.

• Progress in Medical Physics
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• v.7 no.2
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• pp.67-77
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• 1996

Purpose: To get a 3-D coordinates of intracranial target position was investicated in axial, sagittal and coronal magnetic resonance imaging with a preliminary experimented target localizer. Material and methods : In preliminal experiments, the localizer is made of engineering plastic to avoid the distrubance of magnetic field during the MR image scan. The MR localizer displayed the 9 points in three different axial tomogram. The bright signal of localizer was obtjained from 0.1～0.3％ of paramagnetic gadolinium/DTPA solution in T1WI or T2WI. In this study, the 3-D position of virtual targets were examined from three different axial MR images and the streotactic position was compared to that of BRW stereotactic system in CT scan with same targets. Results: This study provided the actual target position could be obtained from single scan with MRI localizer which has inverse N-typed 9 bars. This experiment was accomplished with shimming test for detection of image distortion in MR image. However we have not found the image distortion in axial scan. The maximum error of target positions showed 1.0 mm in axial, 1.3 mm for sagittal and 1.7 mm for coronal image, respectivelly. The target localization in MR localizer was investicated with spherical virtual target in skull cadaver. Furthermore, the target position was confirmed with CRW stereotactic system showed a 1.3 mm in discrepancy. Summary : The intracranial target position was determined within 1.7 mm of discrepancy with designed MR localizer. We found the target position from axial image has more small discrepancy than that of sagittal and coronal image.

• The Journal of Korean Society for Radiation Therapy
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• v.12 no.1
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• pp.58-62
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• 2000

• The Journal of Korean Society for Radiation Therapy
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• v.8 no.1
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• pp.67-69
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• 1996

• 대한방사선치료학회:학술대회논문집
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• 2000.06a
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• pp.31-32
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• 2000