伽玛刀治疗大型三叉神经鞘瘤的临床分析

Gamma knife radiosurgery for large trigeminal schwannoma

目的回顾性分析伽玛刀(γ刀)对大型三叉神经鞘瘤的治疗效果。方法应用Leksellγ刀治疗大型三叉神经鞘瘤30例,肿瘤最大径为31.0～53.0mm。照射肿瘤的平均中心剂量为25.8Gy,平均周边剂量12.2Gy。平均随访时间78个月(24～136个月)。结果症状改善24例,无变化3例,加重2例,死亡1例。肿瘤变化4例肿瘤基本消失,20例明显缩小,3例未增大,3例增大(1例死亡,2例再手术),肿瘤的控制率为90%。γ刀术后30个月再手术患者的病理结果大部分肿瘤组织坏死,残存肿瘤细胞透明变性,核固缩、核异形。结论γ刀对选择性大型三叉神经鞘瘤(最大径≤40mm)有良好的中长期控制作用。

Objective To evaluate the role of gamma knife (GK) radiosurgery in controlling large trigeminal schwannoma.Methods The clinical data of 30 patients suffering from large trigeminal schwannoma with a maximum diameter of 39.0 mm (31.0 to 53.0 mm), who underwent GK radiosurgery, used as the primary treatment modality in 20 patients and used to cure the residuals of tumor after microsurgery in 10 patients, with the maximum irradiation dose to tumor of 25.8 Gy (20.0 to 33.0 Gy) and a tumor margin dose of 12.2 Gy (9.0 to 14.0 Gy), were analyzed respectively.Results The 30 patients had been followed up for 78 months (24 to 136 months). Twenty-nine of the 30 patients were alive, and one patient with malignant trigeminal schwannoma died of tumor progression 36 months after the GK radiosurgery. Neurological deficits were improved in 24 patients and 3 patients' condition remained stable. Two patients' symptoms worsened 5 and 30 months after the GK radiosurgery respectively because of tumor swelling and tumor cyst enlarging. Then these two patients underwent microsurgery and their tumors were subtotally removed. Disappearance of tumor occurred in 4 patients, a marked decrease in tumor volume was observed in 20 patients, three tumors kept unchanged or slightly regressed in volume, and 3 tumors, including that of the patient who died, progressed. The tumor-growth control rate was 90% (27/30). Two patients underwent craniotomy after GK radiosurgery and one of these 2 resected specimens underwent histopathological examination. The histopathological findings of this tumor resected 30 months after GK radiosurgery revealed that most of the tumor tissue necrosed and was full of microcysts, the residual tumor cells in peripheral areas underwent hyaline degeneration, and the nuclei showed pyknosis. Conclusion GK may be a good alternative treatment for selective patients suffering from large trigeminal schwannoma with a maximum diameter ≤40 mm.