Purpose:To develop and evaluate an effective real-time tracking and gating radiotherapy based on dMLC for mobile tumor.Methods:A novel technology has been proposed for mobile tumor radiotherapy,where dMLC is used for real-time tracking tumor,and overlapped projection ratio(OPR)of OAR and tumor in the beam's eye view(BEV)is proposed for the gating control.The performance regarding to dose distribution and OAR protection of the innovative technology is investigated.The dose distribution of PTV and its nearest OAR was calculated and compared with that of traditional static strategy,where gating threshold was selected as 30%,25%,and 20%respectively.Results:Compared with the static field irradiation,the proposed method results to distinguish reduction of the volume directly irradiated to OAR,the received mean dose of OAR decreases from 36.8%to 57.8%,the received maximum dose of OAR decreases from 56.4 to 60.1%,and the DVHs of OAR are clearly better,meanwhile the PTV dose distributions can match that with traditional static strategy.The experimental results of dose distribution and dose volume histogram(DVH)indicate that dMLC-based real-time tracking and OPR based gating provides more effective protection to OAR.Conclusions:The proposed radiotherapy technology based on dMLC and OPR has the effective ability of improving the protection of OAR and reducing normal tissue complication probability(NTCP)for abdominal and thoracic tumor radiotherapy.