• Journal of Korean Neurosurgical Society
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• 제54권2호
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• pp.107-111
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• 2013

Objective : We investigated the effectiveness of stereotactic gamma knife Radiosurgery (GKR) for radioresistant brain metastases with the impact upon histology. Methods : Between April 2004 and May 2011, a total of 23 patients underwent GKR for 67 metastatic brain tumors from 12 renal cell cancers, 5 sarcomas and 6 melanomas. The mean age was 56 years (range, 18 to 79 years). Most of the patients were classified as the Radiation Therapy Oncology Group recursive partitioning analysis class II (91.3%). The synchronous metastasis was found in 6 patients (26.1%) and metachronous metastasis in 17 patients (73.9%). We analyzed the local control rate, intracranial progression-free survival (PFS) and overall survival (OS). Results : The mean tumor volume for GKR was 2.24 cc and the mean prescription dose was 19.4 Gy (range, 10 to 24) to the tumor margin. Out of metachronous metastases, the median duration to intracranial metastasis was 3.3 years in renal cell cancer (RCC), 2.4 years in melanoma and 1.1 years in sarcoma (p=0.012). The total local control rate was 89.6% during the mean 12.4 months follow-up. The six-month and one-year local control rate was 90.2% and 83% respectively. Depending on the pathology, the control rate of RCC was 95.7%, sarcoma 91.3% and melanoma 80.5% during the follow-up. The common cause of local failure was the tumor bleeding in melanoma. The median PFS and OS were 5.2 and 8.4 months in RCC patients, 6.5 and 9.8 months in sarcoma, and 3.8 and 5.1 months in melanoma. Conclusion : The GKR can be one of the effective management options for the intracranial metastatic tumors from the radioresistant tumors. The melanoma showed a poor local control rate compared to other pathologies because of the hemorrhage.

• Radiation Oncology Journal
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• 제11권2호
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• pp.439-448
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• 1993

Leksell 감마나이프(B-형)가 1992년 3월 경희대학교 의과대학 병원에 설치되었다. 선택적 빔 Plugging방법을 이용하여 정상 민감 조직에 대한 저선량 분포를 현저히 줄일 수 있으며, 또한 치료 부위에 더 좋은 선량 분포를 얻을 수 있다. 저선량에 대한 여러가지 선량 분포의 변화에 대한 연구를 하였으며, 사용중인 KULA프로그램의 선량 분포 곡선을 평가하기 위해 필름을 이용한 방사선량 계측을 실시하였고, RFA-3자동 밀도 측정기를 이용하여 평가하였다. 1992년 3월부터 1993년 2월까지 1년동안 100명의 환자중 17명의 환자에 선택적 빔 차폐 방법이 적용되었다. 고선량 영역에서는 측정값과 프로그램에서 제공된 선량 분포가 잘 일치하였다. 뇌하수체 선종의 치료시 치료 부위가 클 경우에는 본 연구 방법의 적용이 매우 중요시 되었으며, 반면에 치료 영역이 작을 경우에는 적절한 헬맷의 선택이 중요함을 알 수 있었다. 치료 환자의 중요 민감 장기의 방사선 선량 평가에서는 뇌간에 3~12 Gy, 시신경 교차에 3~11.2 Gy이었다. 중추신경계 영역의 최적화된 치료를 위하여 다양한 Plugging형태를 임상에 적용하는 것이 방사선에 민감한 정상 조직을 보호하기 위해 매우 중요한 인자가 됨을 알았다.

• 한국방사선학회논문지
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• 제10권7호
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• pp.521-529
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• 2016

감마나이프 방사선수술은 일회에 고방사선량을 조사하는 치료 전략에 기초하기 때문에 렉셀감마플랜의 결과물에 대한 독립적인 검증은 환자의 안전성을 보장하고 치료 오류의 위험을 최소화하는데 중요한 절차 중 하나이다. 기존에 개발된 여러 검증 방법들의 구현을 통해 통계적으로 검토하고 치료에 시도했다. 이 연구의 목적은 감마나이프 치료에 대해 제안된 여러 검증방법의 정확도를 적용하고 평가하는 것이었다. 본 연구에서 감마나이프방사선 수술에 의해 치료된 두개 내 병변을 가진 10명의 환자가 포함되었다. 우리는 최대 선량, 임의의 점에서의 선량, 등선량중심점에서의 치료시간에 관하여 제안된 알고리즘과 렉셀감마플랜으로 획득한 데이터를 비교 하였다. 모든 데이터는 두 개의 상이한 측정 기법을 비교하기 위해 사용되는 통계적 방법인 대응표본 t 검정에 의해 분석되었다. 10가지 사례에서 최대 선량의 통계적 유의성은 제안된 검증방법과 렉셀감마플랜 사이에 관찰되지 않았다. 평균 최대 선량의 차이는 -0.53 Gy에서 3.71 Gy범위내였다. 제안된 검증방법과 렉셀감마플랜에 의해 계산된 임의의 점에서의 선량 또한 통계적으로 유의하지 않았다. 그러나 우리는 등선량중심점에서의 치료시간에 대한 조직최대비율 알고리즘과 렉셀감마플랜사이에 p=0.021인 통계적인 차이가 발견되었다. 통계적 분석에 의하면 제안된 검증방법은 감마나이프 방사선수술의 최상의 치료계획을 위해 최대 선량과 임의의 점에서의 선량을 고려할 때 렉셀감마플랜과 상당히 일치한다고 볼 수 있다. 제안된 검증방법들은 과다선량 조사 가능성을 최소화하기 위한 통상적인 정도관리 절차의 일부분으로 통합될 수 있다고 여겨진다.

• 한국의학물리학회지:의학물리
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• 제7권1호
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• pp.3-7
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• 1996

정위적 방사선수술을 시행하기 위하여 CT, MR, 그리고 digital angiography 의 표적 위치결정의 정확도를 평가하였다. 특정한 지점의 위치가 이미 알려져 있는 (정밀도 : 0.lmm 이내) geometrical phantom 을 CT 혹은 MR로 scan 하였다. Scan 간격은 3mm 이었으며 FOV (Field of View)는 CT의 경우 35cm, MR 의 경우 28cm 이었다. 얻어진 영상은 GE format 의 형태로 TCP/IP를 이용하여 치료계획 컴퓨터로 전달되었다. 각 영상을 컴퓨터로 분석하여 얻은 측정된 좌표값을 이미 알고 있는 값과 비교하였다. Digital angiography 의 경우, 좌표값을 결정하기 위하여 anterior-posterior 방향과 lateral 방향의 film을 얻었으며 이 film은 film scanner를 이용하여 치료계획 컴퓨터로 전달되었다. CT 영상의 위치결정 오차는 1.2$\pm$0.5 mm이었으며 MR의 경우에는 coronal 및 sagittal 영상에 대하여 각각 평균 1.7$\pm$0.4mm, 2.1$\pm$0.7mm의 오차가 있었다. 반면에 Axial 영상의 경우에는 오차가 평균 4.7$\pm$ 0.9mm이었다. Digital angiography 의 위치결정 오차는 0.9$\pm$0.4mm이었다. CT, MR, 그리고 Angiography 등과 같은 진단장비를 이용하여 표적의 위치 및 형태를 정의하는데 있어서의 정확도는 진단 영상의 분해능 및 distortion 과 밀접한 관련을 가지고 있다. CT의 경우, 위치결정 오차는 주로 영상의 slice 간격에 따른 분해능에 의존하며 MR 영상의 경우에는 영상자체의 분해능과 더불어 head frame에 의한 distortion이 크게 작용하였다. 반면에 Digital angiography의 경우에는 fiducial marker의 distortion으로 인한 오차가 가장 크게 영향을 주었다. 본 연구의 결과는 치료계획시 PTV(Planning Target Volume)를 결정할 때 반드시 고려되어야 한다.

• Journal of Korean Neurosurgical Society
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• 제55권3호
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• pp.136-141
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• 2014

Objective : The aims of this study are to identify interpersonal differences in defining coordinates and to figure out the degree of distortion of the MRI and compare the accuracy between CT, 1.5-tesla (T) and 3.0T MRI. Methods : We compared coordinates in the CT images defined by 2 neurosurgeons. We also calculated the errors of 1.5T MRI and those of 3.0T. We compared the errors of the 1.5T with those of the 3.0T. In addition, we compared the errors in each sequence and in each axis. Results : The mean difference in the CT images between the two neurosurgeons was $0.48{\pm}0.22mm$. The mean errors of the 1.5T were $1.55{\pm}0.48mm$ (T1), $0.75{\pm}0.38$ (T2), and $1.07{\pm}0.57$ (FLAIR) and those of the 3.0T were $2.35{\pm}0.53$ (T1), $2.18{\pm}0.76$ (T2), and $2.16{\pm}0.77$ (FLAIR). The smallest mean errors out of all the axes were in the x axis : 0.28-0.34 (1.5T) and 0.31-0.52 (3.0T). The smallest errors out of all the MRI sequences were in the T2 : 0.29-0.58 (1.5T) and 0.31-1.85 (3.0T). Conclusion : There was no interpersonal difference in running the Gamma $Plan^{(R)}$ to define coordinates. The errors of the 3.0T were greater than those of the 1.5T, and these errors were not of an acceptable level. The x coordinate error was the smallest and the z coordinate error was the greatest regardless of the MRI sequence. The T2 sequence was the most accurate sequence.

• Journal of Korean Neurosurgical Society
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• 제54권3호
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• pp.246-249
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• 2013

A solitary fibrous tumor (SFT) is a rare neoplasm originated from the pleura, but they can occur in a variety of extrathoracic regions. Although many cases of primary SFT have been reported, there are extremely rare repots to date of a malignant SFT in the spine or skull. A 54-year-woman visited our hospital due to low back pain and both leg radiating pain. Several imaging studies including magnetic resonance imaging and computed tomography revealed expansive enhanced lesions in the occipital bone, T8, S1-2, and ilium, with neural tissue compression. We performed surgical resection of the tumor in each site, and postoperative radiosurgery and chemotherapy were performed. However, after six months, tumors were recurred and metastasized in multiple regions including whole spine and lung. The authors report here the first case of patient with malignant SFT of tandem lesions in the various bony structures, including skull, thoracic spine, and sacral spine, with a rapid recurrence and metastasis. Although malignant SFT is extremely rare, it should be considered in the differential diagnosis and carful follow-up is needed.

• 대한방사선치료학회지
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• 제9권1호
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• pp.50-55
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• 1997

The optimal management of uveal melanoma is still a matter of controversy. To determine the effect of Gamma Knife surgery for patients with uveal malanoma. the authors reviewed the results of 5 patients underwent Gamma Knife sugery between Sep. 1993 and Dec. 1996. The mean age was 60.7 years ranging from 42.5 to 76.5 years. Median follow-up was 13.29 months and the patient with follow up period more than 6 months was 4. The mean tumor volume was $3442 mm^3$(mean diameter 15.3 mm) and all patients were irradiated with a mean maximum dose of 74Gy(range $60\~80\;Gy$), using the $50\%$ isodose. After Gamma Knife surgery. one pateint showed complete disapperance in tumor size with follow-up 32 months, one enucleation due to progression, and 2 no interval change. In regard to vision, one patient blind. one enucleation, and 2 patients had no interval change. According to our experiences, Gamma Knife surgery for uveal melanoma be able to achieve local tumor control, spare the eyeball, and have possibility of save vision.

• Journal of Korean Neurosurgical Society
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• 제58권5호
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• pp.471-475
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• 2015

Intracerebral hemorrhage (ICH) is common among various types of storkes; however, it is rare in young patients and patients who do not have any risk factors. In such cases, ICH is generally caused by vascular malformations, tumors, vasculitis, or drug abuse. Basal ganglia ICH is rarely related with distal lenticulostriate artery (LSA) aneurysm. Since the 1960s, a total of 29 distal LSA aneurysm cases causing ICH have been reported in the English literature. Despite of the small number of cases, various treatment methods have been attempted : surgical clipping, endovascular treatment, conservative treatment, superficial temporal artery-middle cerebral artery anastomosis, and gamma-knife radiosurgery. Here, we report two additional cases and review the literature. Thereupon, we discerned that young patients with deep ICH are in need of conventional cerebral angiography. Moreover, initial conservative treatment with follow-up cerebral angiography might be a good treatment option except for cases with a large amount of hematoma that necessitates emergency evacuation. If the LSA aneurysm still persists or enlarges on follow-up angiography, it should be treated surgically or endovascularly.

• Journal of Korean Neurosurgical Society
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• 제52권2호
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• pp.148-151
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• 2012

Intracranial squamous cell carcinoma is extremely rare, with most of the cases arising from malignant transformation of an epidermoid or a dermoid cyst. The patient presented with facial weakness. Initial magnetic resonance imaging revealed a mass in the right cerebellopontine angle. A subtotal resection was performed via right retrosigmoid suboccipital approach. Histopathological findings were consistent with an epidermoid tumor. Five months later, the patient underwent gamma knife radiosurgery due to highly probable recurrent epidermoid tumor. Two years after, the patient's neurological deficit had been newly developed, and follow-up magnetic resonance imaging demonstrated a large contrast-enhancing tumor in the left cerebellopontine angle, which compressed the brainstem. After resection of the tumor, histopathological examinations revealed a squamous cell carcinoma probably arising from an underlying epidermoid cyst. We report a case of an epidermoid tumor in the cerebellopontine angle that transformed into a squamous cell carcinoma.

• Journal of International Society for Simulation Surgery
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• 제2권2호
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• pp.58-63
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• 2015

Image-guided neurosurgery (IGN) is a technique for localizing objects of surgical interest within the brain. In the past, its main use was placement of electrodes; however, the advent of computed tomography has led to a rebirth of IGN. Advances in computing techniques and neuroimaging tools allow improved surgical planning and intraoperative information. IGN influences many neurosurgical fields including neuro-oncology, functional disease, and radiosurgery. As development continues, several problems remain to be solved. This article provides a general overview of IGN with a brief discussion of future directions.