Effect of volumetric modulation arc therapy on hippocampal protection and cognitive function in breast cancer patients with brain metastases
WANG Cong
ZHANG Zhilin
LI Jinqiu
Abstract：Objective To investigate the effect of volumetric modulation arc therapy on hippocampal protection and cognitive function in breast cancer patients with brain metastases.Methods A total of 20 breast cancer patients with brain metastases who were initially treated from August,2021 to August,2022 were enrolled.They were randomly assigned into the intensity-modulated radiation therapy(IMRT)group and volumetric modulation arc therapy(VMAT)group,with 10 cases per group.The dose-volume histogram(DVH),conformity index(CI),homogeneity index(HI),machine unit(MU),hippocampal avoidance(HA)and other normal tissues of two groups were evaluated.The Mini-Mental State Examination(MMSE)before and immediately after the treatment,and 1 month and 3 months after the treatment was evaluated.Results In the DVH images,the planning target volume with hippocampal avoidance(PTV-HA,31.71±0.06 vs.31.38±0.08),D98％(dose received by 98％of target volume;29.54±0.24 vs.27.78±0.63),D95％(dose received by 95％of target volume;30.21±0.12 vs.29.65±0.51),D2％(dose received by 2％of target volume;32.91±0.02 vs.32.82±0.12),and D50％(dose received by 50％of target volume;31.79±0.06 vs.31.56±0.10)were significantly higher in the VMAT group than those of IMRT group(all P＜0.05).The volume of 95％,100％,105％of PTV-HA prescription dose in the VMAT group were significantly higher than those of the IMRT group(all P＜0.05).Compared to IMRT group,a significantly increased CI,but significantly decreased HI,MU and treatment time were detected in the VMAT group(all P＜0.05).In normal tissue dose limitation,the mean HA dose(8.46±0.24 vs.8.67±0.11),maximum dose(13.51±1.04 vs.14.57±1.19),and maximum dose to both eyes(22.39±0.64 vs.25.78±0.43)were all significantly lower in the VMAT group than the IMRT group(all P＜0.05).At post-radiotherapy follow-up visits,there was a significant difference in the MMSE score at 3 months between the two groups([24.95±1.41]points vs.[23.31±1.85]points,P=0.039).Conclusion Compared with IMRT,VMAT may have a better target volume dose coverage and better hippocampal protection in breast cancer patients with brain metastases,which may delay the cognitive dysfunction in a certain extent.
Keywords：breast cancer brain metastasesvolumetric modulation arc therapyhippocampal avoidancemini-mental state examination
Publication Date：2024-10-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 3084-3087,3091 )