[Gamma knife radiosurgery for temporal bone chondroblastoma: case report].

A case with chondroblastoma arising from the right temporal bone was reported. A 52-year-old woman demonstrated residual tumor growth after surgical excision. The patient presented continuous right temporalgia and right facial twitch while opening her mouth. The tumor was an expansile mass (tumor volume: 12.8 cm3) and showed homogeneous hypo-intensity on T1 and T2-weighted images, but little contrast enhancement. The patient underwent gamma knife radiosurgery (GKR: marginal dose: 12 Gy, maximum dose: 24 Gy). One month later, her symptoms improved completely. The size of the tumor was reduced to 6.4 cm3 twenty months after GKR. The patient has been free of recurrence and side effects for four years since GKR. GKR may be useful to control residual chondroblastoma of the skull after surgery.

[Case of a ruptured vertebral artery dissecting aneurysm recanalized after internal trapping].

A 35-year-old male experienced a sudden onset of severe headache. A CT scan revealed subarachnoid hemorrhage. By cerebral angiography, he was diagnosed as having a ruptured right vertebral artery dissecting aneurysm (VADA). It was successfully treated by endovascular occlusion of the affected site, including the aneurysm and parent artery, by using detachable coils. A follow-up angiography obtained seven months after the first treatment revealed the recanalization of the right vertebral artery and dissected aneurysm in an antegrade fashion. A skull X-ray image was useful for detecting the change in appearance of the coils. The second embolization was successfully performed in the same manner. Based on this rare case, the authors emphasize that a careful angiographic analysis and complete internal trapping of the dissecting site are important in the treatment of the ruptured VADA.

[A case of brain metastasis from gastric cancer involving bilateral middle cerebellar peduncles].

A case with brain metastasis involving bilateral middle cerebellar peduncles (bMCP) was reported. A 71-year-old male with gastric cancer was treated for multiple brain metastasis by gamma knife radiosurgery (GKR) in September, 2004. Two months after the initial GKR, MRI showed asymmetrical enhanced lesions involving bMCP. A few months later, MRI revealed an expansional infiltration of bMCP lesions. The patient had presented with headache loss of appetite, cerebellar ataxia, diplopia and slight dysmetria. PET showed 2-deoxy-2- [18F] fluoro-D-glucose (FDG) uptake of the bMCP lesions. The lesions were diagnosed as brain metastasis of gastric cancer. The patient underwent his second GKR (marginal dose : 19Gy, maximum dose 38Gy) MRI revealed the disappearance of the tumors 3 months after the second GKR. One year later, the patient showed no evidence of recurrence. For the last time, our case was diagnosed as brain metastasis from gastric cancer without meningeal carcinomatosis. It was suggested that FDG-PET can provide additional information about the lesion of bMCP. GKR may be useful to treat the tumor in bMCP.