摘要
目的探讨肺部肿瘤大分割放疗患者伽玛刀、固定野调强放疗(Intensity Modulated Radiation Therapy,IMRT)和容积调强放疗(Volumetric Modulated Arc Therapy,VMAT)计划的剂量学差异,分析三种立体定向治疗方式在肺部肿瘤治疗上的优势和不足。方法选取2018年至2020年在海军第九七一医院接受放疗的肺转移瘤患者20例,利用计划系统对20例患者分别制定伽玛刀、IMRT和VMAT治疗计划,通过剂量体积直方图分析靶区及危及器官的剂量、体积等相关参数并做统计学分析,比较三种治疗计划的剂量学差异。结果患侧肺及全肺V_(5)、V_(10)、V_(15)、V_(20)、V_(25)、V_(30),伽玛刀低于IMRT和VMAT(P<0.05);IMRT比VMAT的V_(10)、V_(15)小(P<0.05),而V_(25)、V_(30)则略高于VMAT,差异无统计学意义(P>0.05)。三种治疗方式的患肺平均剂量D_(mean)基本相同(P>0.05);全肺平均剂量D_(mean),伽玛刀与IMRT无明显差异(P=0.106),但伽玛刀比VMAT略低(P=0.025)。采用伽玛刀治疗,心脏V_(20)、V_(30)、V_(40)整体好于基于加速器的IMRT和VMAT,除了与VMAT相比V_(40)差异较小(P=0.086)外,其他差异均有统计学意义(P<0.05)。伽玛刀心脏平均剂量D_(mean)低于IMRT(P=0.007),其他各组无明显差别(P>0.05)。伽玛刀治疗的脊髓最大剂量低于IMRT(P<0.05),而IMRT和VMAT则相差不大(P=0.411)。伽玛刀、IMRT和VMAT三者的食管D_(mean)依次增高(P<0.05);最大剂量D_(max)伽玛刀明显低于VMAT(P=0.029),而伽玛刀与IMRT以及IMRT与VMAT则没有明显差别(P>0.05)。IMRT的适形指数好于伽玛刀和VMAT(P<0.05);而伽玛刀和VMAT则无明显差别(P=0.866)。伽玛刀的不均匀指数明显高于IMRT和VMAT(P<0.05),VMAT略高于IMRT(P=0.008)。采用伽玛刀治疗的靶区D_(max)和D_(mean)明显高于IMRT和VMAT(P<0.05),VMAT则略高于IMRT(P<0.05)。结论伽玛刀靶区剂量分布最不均匀,适形度稍差,但能更好的保护周围正常肺组织和其他危及器官,对较小的肺叶内肿瘤尤其适合;IMRT用于体部立体定向放射治疗(Stereotactic Body Radiation Therapy,SBRT)比VMAT降低了肺内低剂量辐射的范围,但是高剂量辐射范围稍大;VMAT在用于肺叶内肿瘤SBRT时应该慎重。
Objective To explore the dosimetric differencees of gamma knife,intensity modulated radiation therapy(IMRT)and volumetric modulated arc therapy(VMAT)planning in patients with lung tumor treated by hypofractionated radiotherapy.And to analyze the advantages and disadvantages of three stereotactic therapies in the treatment of lung cancer.Methods A total of 20 patients with lung metastases who received radiotherapy in Navy 971 Hospital from 2018 to 2020 were selected.Using the planning system,20 patients were treated with gamma knife,IMRT and VMAT.The dose,volume and other related parameters of the target and the organs at risk were analyzed by dose volume histogram,and statistical analysis was performed to compare the dosimetric differences between the three treatment plans.Results The levels of V_(5),V_(10),V_(15),V_(20),V_(25),V_(30) in the affected lung and whole lung,gamma knife is lower than those in IMRT and VMAT(P<0.05).IMRT was lower than V_(10) and V_(15) of VMAT(P<0.05).However,V_(25) and V_(30) were slightly higher than VMAT,there was no significant statistical difference(P>0.05).The average dose of D_(mean) in the affected lung of the three treatments was basically the same(P>0.05).There was no significant difference in the average dose D_(mean) of whole lung between gamma knife and IMRT(P=0.106),but gamma knife was slightly lower than VMAT(P=0.025).Treated with gamma knife,the V_(20),V_(30),V_(40) of heart,overall were better than accelerator-based IMRT and VMAT,except that V_(40) had little difference compared with VMAT(P=0.086),other differences were statistically significant(P<0.05).The average cardiac dose of gamma knife D_(mean) was lower than that of IMRT(P=0.007),but there was no significant difference among other groups(P>0.05).The maximum dose of spinal cord treated with gamma knife was lower than that of IMRT(P<0.05),but there was no significant difference between IMRT and VMAT(P=0.411).The esophageal D_(mean) of gamma knife,IMRT and VMAT increased sequentially(P<0.05).The maximum dose of D_(max) gamma knife was significantly lower than that of VMAT(P=0.029).But there were no significant differences between gamma knife and IMRT or between IMRT and VMAT(P>0.05).The conformity index of IMRT was better than that of gamma knife and VMAT(P<0.05),but there was no significant difference between gamma knife and VMAT(P=0.866).The homogeneity index of gamma knife was significantly higher than that of IMRT and VMAT(P<0.05),the VMAT was slightly higher than that of IMRT(P=0.008).The D_(max) and D_(mean) of the target area treated with gamma knife were significantly higher than those of IMRT and VMAT(P<0.05),and the VMAT was slightly higher than that of IMRT(P<0.05).Conclusion The dose distribution in the target area of gamma knife is the most uneven,and the conformity index is slightly worse,but it can better protect the surrounding normal lung tissue and other organs at risk,especially suitable for smaller intralobar tumors.IMRT used in stereotactic body radiation therapy(SBRT)reduces the range of low-dose radiation in the lung compared with VMAT,but the range of high-dose radiation is slightly larger.VMAT should be used with caution in the application of SBRT in intralobar tumors.
作者
吕海鹏
刘晓
康静波
赵焕升
王凯
胡范祥
李翊
LV Haipeng;LIU Xiao;KANG Jingbo;ZHAO Huansheng;WANG Kai;HU Fanxiang;LI Yi(Department of Radiotherapy,Navy 971 Hospital of Chinese People’s Liberation Army,Qingdao Shandong 266000,China;Department of Radiotherapy,The Sixth Medical Center of PLA General Hospital,Beijing 100048,China)
出处
《中国医疗设备》
2021年第4期122-126,共5页
China Medical Devices
基金
国家重点研发计划项目(2017YFC0113701)。
关键词
立体定向放射治疗
伽玛刀
固定野调强放疗
容积调强放疗
肺部肿瘤
剂量学
stereotactic body radiation therapy
gamma knife
intensity modulated radiation therapy
volumetric modulated arc therapy
lung tumor
dosimetry
