Radiosurgery for Cerebrovascular Disease / 대한뇌혈관학회지

The stereotactic radiosurgery for arteriovenous malformation (AVM) began in the early 1970s. Nowadays, by 2000 world-wide, more than 27,500 patients have undergone Gamma Knife radiosurgery for cerebrovascular disease (CVD). New concepts, consisting of obliteration rate, postradiosurgical hemorrhagic risk, dose selection for treatment, and radiosurgery for pediatric AVM, medium-to-large sized AVM, cavernous malformation, venous angioma, so on, have been established. Gamma Knife radiosurgery has been considered as an effective management stratege with relatively few side effects for AVM. However, recently delayed radiation-induced complications were reported in 3.2 to 12.5% in range. Therefore, the long-term follow-up is thought to be mandatory even after treatment goal, complete obliteration, is confirmed.

Long-term Complications of Arteriovenous Malformation Treated by Gamma Knife Radiosurgery: A 10-Year Experience

OBJECTIVE: The authors conduct a retrospective study to analyze long-term complications of Gamma knife radiosurgery for cerebral arteriovenous malformation(AVM). METHODS: We performed a detailed long-term follow-up study of 100 patients, who could be followed more than 2 years, with AVMs treated by Gamma knife radiosurgery during the last 10 years. At the time of radiosurgery, the mean age was 31.6 years(range : 7-65). The mean follow-up period after radiosurgery was 63.7 months(range : 24-116) except one mortality related with rebleeding. Mean target volume was 5039.2mm3(range : 105-38400). In all of the patients, AVMs were completely covered with a 40-80% isodose profile. The selected target dose delivered by the Gamma Knife was 7.2 to 33 Gy(mean : 22.2 Gy) at the periphery. RESULTS: Angiographic complete obliteration rate was 80% at 2 years after radiosurgery. Rebleeding occur in 4 cases at 4, 8, 44, 98 months after radiosurgery, respectively. Annual bleeding rate was 0.6%. Among them, one patient died. Postradiosurgical complications consisted of adverse radiation effects (ARE) in 19 patients, cyst formation in three, and asymptomatic vascular stenosis in one. Symptomatic ARE was 8% and the mean time from the last radiosurgery to ARE was 12.4 months(1-29) on follow-up images. Three patients, who have been verified angiographically complete obliteration, developed cyst formation within previous irradiated area at 48, 102, 115 months after radiosurgery respectively. Two of them underwent cystic aspiration with catheter drainage. CONCLUSION: The individual incidence of postradiosurgical complication was approximately from 3 to 19%, which is higher than expected. Long-term follow-up is mandatory even after complete nidus obliteration.

A Case of Cerebral Metastasis from Malignant Fibrous Histiocytoma

This is a rare case of cerebral metastasis from malignant fibrous histiocytoma(MFH) of the soft tissue. A 62-year-old man underwent craniotomy for resection of multiple intracerebral masses under the impression of metastatic brain tumor with unknown primary site. Preoperative investigation failed to detect any extracranial lesion. At six months after the operation and whole brain radiotherapy, right shoulder mass was detected to grow and excised. Specimen from the brain and shoulder lesions revealed identical pathological findings of malignant fibrous histiocytoma except existence of glial fibrillary acidic protein(GFAP)-positive cells only in brain lesions. Palliative radiotherapy was performed for subsequently developing metastatic lesions in skeletal system. At twelve months after initial diagnosis recurrent lesion at right shoulder was detected and chemotherapy is given. This case is unique because metastatic brain lesion from MFH is rare and also cerebral metastasis as an initial manifestaion of MFH has not been reported before. Another important finding is that there was expression of GFAP only in brain lesions but not in extracranial primary site lesion. Although the presence of GFAP-positive cells is thought as one of characteristic histological findings of primary intracrainal MFH, our observation supports the hypothesis that GFAP-positive cells in primary intracranial MFH may be nonneoplastic astrocytes secondarily involved by MFH.

Surgical Treatment of Seizures in Malformations of Cortical Development (MCD) / 대한간질학회지

OBJECT: Surgical treatment of cortical dysplasias (CDs) presenting with intractable seizures is challenging, because isualization/localization of the lesion is difficult, correlation with seizure foci needs comprehensive investigations, and the reported surgical results are not satisfactory. We report our result of surgical treatment of CD classified from the surgical point of view. METHODS: Definition of CD was a visible dysplastic lesion on MRI or MRI-negative (normal MRI) case with pathological diagnosis of moderate to severe dysplasia. During the last 4.5 years, we had operated on 36 cases of intractable epilepsy with CDs. We divided the 36 cases into 4 groups ; Group A : diffuse bilateral hemispheric dysplasia, Group B : diffuse lobar dysplasia, Group C : focal dysplasia, and Group D : moderate to severe degree of cortical dysplasia with normal MRI. All but one patient in Group C were monitored at EMU using subdural electrodes for seizure localization and functional mapping. RESULTS: The incidence of CD in the whole epilepsy surgery cases was 12.4%. Mean age was 21.3 years. Mean age at seizure onset was 8.5 years. Mean follow up period was 26.0 months. Twenty-six (72.2%) patients (20 and 6, respectively) belong to Engel Class I and II. There were 5, 9, 9, and 13 cases in Groups A, B, C, and D, respectively. Groups A and B had significantly lower age at seizure onset and significantly poorer surgical outcome compared to Groups C and D (p<0.05). If the outcome was compared on the extent of removal of CD, patients with completely removed CD had very significantly better outcome than those with partial removal (p<0.001). CONCLUSIONS: We conclude that intractable epilepsy with CD can be treated surgically with comprehensive preoperative approaches. Deliberate resective procedures aiming at complete removal of dysplastic tissue ensure excellent seizure control without permanent neurological deficit.