脑转移瘤手运动区MR功能成像在伽玛刀治疗中的初步应用

目的探讨应用功能MR成像（fMRI）指导脑转移瘤伽玛刀剂量计划时保护手运动区的价值。方法10例毗邻手运动区的脑转移瘤患者行fMRI检查。剂量计划时，参考功能图像使手运动区所覆盖的等剂量曲线值低于30％。结果所有病例均有中央沟变形、伸长和移位，手运动区变形。9例病灶同侧活动指数（IAI）〈1，1例IAI〉1，中位数为0．51，9例患侧信号强度上升百分率（SIRP）为2．70，较健侧4．32低（Z=-2．248，P=0．025）。治疗后随访，9例患侧手肌力逐渐恢复，治疗后3个月IAI1．27（Z=-2．197，P=0．028）、SIRP5．22（Z=-2．807，P=0．005）以及治疗后6个月IAI1．39（Z=-2．366，P=0．018）、SIRP5．69（Z=-2．701，P=0．007）均大于伽玛刀治疗前，两者间变化差异有统计学意义。结论初步研究表明rMRI指导放射外科剂量计划，保护脑运动区。

Initial functional MR imaging study of the motor hand area in brain metastases with gamma knife treatment

Objective Initially investigate the role of functional MRI(fMRI) in guiding gamma knife treatment plans of brain metastases for protecting the motor hand representation area(HRA). Methods Before gamma knife treatment, fMRI were obtained respectively from 10 patients who suffered from brain metastases adjacent to the HRA. Gamma knife dose plans were constructed that kept the HRA outside of the 30% isodose curves. Results The central sulcuses were distorted, stretched and displaced. The HRA partly or diffusely distorted. The lesion ipsilateral activation index (IAI) of 9 cases were less than 1, 1 case was more than 1, the median was 0.51. The signal intensity raise percent (SIRP) of 9 cases were less than the contralateral sides (Z=-2.248, P=0.025). After gamma knife treatment, 9 cases muscle force were gradually recovered, the IAI after 3 months(Z= -2.197, P=0.028),the SIRP after 3 months(Z= -2.807, P=0.005)and the IAI after 6 months(Z=-2.366,P=0.018),the SIRP after 6 months(Z= -2.701, P=0.007)of 9 cases were significantly higher than before. Conclusion Initially proved that fMRI may guide gamma knife treatment plans to protect brain motor area.