体部伽玛刀照射正常脊髓所致放射损伤的实验研究

The Research of Spinal Cord Injury Induced by Body Gamma Knief

目的 :探讨体部伽玛刀立体定向照射 (SRT)对正常脊髓放射损伤的效应。方法 :按不同剂量分3组照射新西兰家兔腰段脊髓 :①高剂量组 ,总量 36Gy/ 6次 (6Gy/次 ,隔日 1次 ) ;②中剂量组 ,总量 30Gy/ 6次 (5Gy/次 ,隔日 1次 ) ;③低剂量组 ,总量 2 4Gy/ 6次 ,(4Gy/次 ,隔日 1次 )。同时设 3个相应常规分割组 2 .0Gy/ (次·d) ,5次 /周 ,6 0 Co治疗机照射 ,总量分别为 36 ,30 ,2 4Gy。结果 :SRT高剂量组 4个月时出现截瘫 ,其他 2组及 3个常规组均未出现。于 4个月、8个月解剖病理发现SRT高、中低组分别出现脊髓重度变性、中度变性和轻度变性 ,而 3个常规组未发现异常。结论 :总剂量相同情况下 。

s Objective:To explore the injury of normal spinal cord irradiated by body gamma Knief.Methods:In this experiment,the rabbit were divided into three stereotactic irradiation groups:①High dose group(HD):the total doses were 36 Gy/6 f(6 Gy/f,qod);②Middle dose group(MD):the total doses were 30 Gy/6 f(5 Gy/f,qod);③Low dose group(LD):the total doses were 24 Gy/6 f (4 Gy/f,qod).The normal lumban spinal cord of rabbit were radiated by Body Gamma Knief.Otherwise,three conventional fraction groups(CF) were used as controls:the spinal cord was radiated by Cobalt 60 unit(2 Gy/f,5 f/w).The total dose were 36,30 and 24 Gy,respectively.Results:Paralysis was seen in HD and wasn't seen in MD,LD and three CF four months after irradiation.Severe,moderate and mild degeneratings were found in spinal cord four and eight months after irradiation in HD,MD and LD,respectively.Spinal cord degenerating wasn't found in the three CF four and eight months after irradiation.Conclusions:If the total doses are equal,the radiation induced injury of spinal cord by Body gamma knief is heavier than the conventional fraction radiation.