伽玛刀、IMRT、VMAT治疗复发高级别胶质瘤剂量学分析OACSTPCD

Objective By analyzing the dosimetric differences of gamma knife,fixed field intensity modulated radiation therapy(IMRT)and volumetric modulated arc therapy(VMAT)in patients with recurrent high-grade glioma,to discuss the advantages and disadvantages of the three radiotherapy methods.Methods A total of 19 patients with recurrent high-grade gliomas who received radiotherapy in No.971 Hospital of The People's Liberation Army Navy from January 2020 to January 2022 were selected as the study objects.The gamma knife,fixed field IMRT and VMAT treatment plans were designed in treatment planning system.Fixed field IMRT and VMAT were designed target uniform dose plan and target simultaneous integrated boost(SIB)plan(SIB-IMRT,SIB-VMAT)respectively,requiring the prescription dose to contain 95%volume.The evaluation parameters included low-dose area V5,brain radiation necrosis index V12,target conformal index(CI),target homogeneity index(HI),target maximum dose(Dmax),average dose(Dmean)and gradient index.Results Among the five treatment plans,the V5 of SIB-IMRT was lower than that of fixed field IMRT and SIB-VMAT(both P<0.05);The V12 of gamma knife was the lowest(all P<0.05),and The V12 of SIB plan were lower than that of conventional plan(SIB-IMRT vs.fixed field IMRT,SIB-VMAT vs.VMAT)(all P<0.05).There was no statistically significant difference in CI between fixed field IMRT and VMAT,SIB-IMRT and SIB-VMAT(all P>0.05),and all better than gamma knife(all P<0.05).There was no statistically significant difference in HI and Dmean between gamma knife and SIB-IMRT,SIB-VMAT(both P>0.05).Conclusion The protective effect of gamma knife on normal brain tissue is better,but the conformal degree of complex target area is slightly worse.The conformal degree of fixed field IMRT and VMAT is higher,and SIB-IMRT and SIB-VMAT can reach the target dose distribution similar to gamma knife,and the dose of normal brain tissue is lower than that of conventional IMRT.