伽玛刀治疗颅内肿瘤的光镜及电镜观察

Observation on intracanial tumor after gamma knife radiosurgery with light and electron microscope

目的探讨伽玛刀（γ-刀）治疗颅内肿瘤的形态学变化及其与临床的关系。方法应用光镜、电镜观察16例γ-刀照射后颅内肿瘤手术切除标本的病理形态学变化，其中星形细胞瘤7例，少突胶质细胞瘤2例；脑膜瘤2例；颅咽管瘤1例；血管母细胞瘤1例；垂体腺瘤1例和转移性腺癌2例。结果γ-刀照射后肿瘤中心和肿瘤边缘的瘤细胞及血管均出现不同程度的凝固性坏死，恶性肿瘤呈急性坏死，良性肿瘤呈延迟性坏死；边缘部位残留的瘤细胞较中心部位多，肿瘤旁脑组织中神经元、胶质细胞及血管均出现不同程度的损伤，但主要以胶质细胞损伤为显著。结论残留的瘤细胞是肿瘤复发的形态学依据，γ-刀对肿瘤旁脑组织的损伤与脑水肿的产生有密切关系。提示临床应注意选择适当的照射剂量及肿瘤大小，以防止肿瘤复发和预防脑水肿的发生。

Objective To explore the relationship between pathological and clinical changes of intracranial tumor after gammaknife radiosurgery. Methods Sixteen intracranial tumors after gamma knife radiosurgery were observed by light and electronmicroscopy. Histologically, 7 types were identified: astocytoma (7 cases), oligodendrolioma (2), meningioma (2), craniopharegioma(1), hemagioblastoma (1), pituitary edenoma (1), and metastatic adenocacinoma (2). Results The coagulation necrosis of variousdegree occured in the tUmor cells and blood vessel of central and peripheral tUmor areas. The malignant tUmor developed acutenecrosis and the benign one exhibited delaied radiation necrosis. The necrosis in central tUmor area was more extensive than in theperipheral tumor area Survived tUmor cells in both the central and peripheral tUmor areas aller radiation were observed. The numberoftUmor cells that survived the radiation was myer in the peripheral area than in the central area. Additionally, the lesion was foundin the nerve cells, atocytes and blood vessels in the brain tissue near the tljmor. Conclusions Tumor cells that survive radiation,as confirmed in this investigation, are likely to be the resource of tumor recurrence. It was found that the brain edema was closelyassociated with lesion near tUmor. In eddition, these results suggest that in light of tUmor recurrence, the dose of the radiation and theselection of the tUmor patients should be further optimized.