Application Value Of DTI Tracing The Whole Visual Pathway Fiber Bundle In Postoperative Intensity Modulated Radiotherapy Plan Of Cerebral Gliomas

Objective To analysis whether the whole visual pathway fiber bundle showed by diffusion tensor imaging(DTI) can be used in guiding the postoperative intensity modulated radiotherapy plan of cerebral gliomas.Methods From 2013 to 2015,a total of 31 patients with confirmed cerebral gliomas underwent conventional and contrast-enhanced MRI and DTI before postoperative radiotherapy.In order to delineate the radiotherapy target volume,organs at risk,the visual pathway fiber bundle,tractography data sets were fused with correlation MR and CT anatomy image by importing it to radiotherapy planning system.Two sets of intensity modulated radiotherapy plan,which considered or did not consider the dose protective effect of the optic tract and optic radiation,were formulated and compared.Results Both the protective radiotherapy and unprotected plans were ensured the therapeutic dose to the target volume and conventional organs at risk had been protected,and there were no statistically significant differences between the two plans in CI and HI of PTV(P=0.875,0.597).The doses patients suffered by using the protective IMRT plan were lower than the unprotected IMRT plan both in affected,unaffected side optic tract and optic radiation.The Dmax and Dmean of PTV in ipsilateral optic tract respectively decresed 9.01% and 9.05%,and the contralateral side decresed 17.96% and 15.52%.The doses in ipsilateral optic radiation decresed 5.37% and 5.48%,and the contralateral side decresed 12.89% and 11.21%.Conclusions DTI can display the location,shape of the whole visual pathway fiber bundle,and the relationship with postoperative radiotherapy target volume of cerebral gliomas,and formulate protective treatment plan to reduce the radiation dose suffered by the optic tract and optic radiation,thereby reducing the visual dysfunction risk after radiotherapy.