Research on Appropriate Parameters of TOMO in HP-WBRT for MRI/CT Fusion Image and CT Image Delineation of the Hippocampal Region
Objective To explore the appropriate parameters for the application of spiral tomotherapy(TOMO)in hippocampal protective whole brain radiotherapy in mapping the hippocampus between MRI/CT fusion images and CT images.Methods Data from 66 patients who underwent HP-WBRT at Shaanxi Provincial Cancer Hospital from January 2017 to December 2022 were collected as research objects.Among them,36 patients had hippocampal delineation based on MRI/CT fusion images,while 30 patients had delineation based on CT images.Different parameter combinations were adjusted,including modulation factor(MF),field width(FW),and pitch(Pitch),to evaluate the target coverage and organ at risk coverage of treatment plans to explore the suitable parameters for TOMO.Results The volume of the hippocampal region delineated based on MRI/CT fusion images(HPL,HPR on both sides)was significantly larger than that delineated based on CT images(P<0.001).The optimal MF for TOMO was 2.7 when using MRI/CT fusion images for hippocampal delineation,and 2.5 when using CT images.The optimal FW for both approaches was 2.5 cm.The optimal Pitch for MRI/CT fusion images was 0.287,while for CT images,both 0.287 and 0.430 met the requirements.Conclusion By comparing different parameter schemes of MRI/CT fusion images and CT mapping of hippocampus,the appropriate parameters of TOMO for hippocampal protective whole brain radiotherapy are obtained,which can provide references for optimizing radiotherapy schemes and improve the accuracy and safety of hippocampal protective whole brain radiotherapy.
万方数据
维普
