Purpose There is an increasing interest of using Cerenkov emission for QA and dosage verification in radiotherapy.Here we study a new therapy of using photosensitizers,protoporphyrin IX(PpIX),which the PpIX is excited by Cerenkov emission from 45MV X-Ray of A45 accelerator and selectively be absorbed by tumor cells,to treat deep and shallow tumors.As Photo-Dynamic Therapy(PDT)is only an effective treatment modality for some superficial tumors,this new therapy method can treat different depths tumor and named Radio-Dynamic Therapy(RDT).MethodsWe investigated mechanisms of Cerenkov emission that produced from the 45MV X-Ray of A45 accelerator.After Monte Carlo Genat4 code simulated Cerenkov emission intensity distribution,we studied the characteristics of Cerenkov emission spectroscopy,the excitation function and efficiency distribution for photosensitizers,PpIX.Experimentally,in the role of patented coenzyme,we also discussed strong catalytic effect of PpIX excitation from the Cerenkov emission.ResultsThe MC simulations and experiments show:1)intensity of Cerenkov emission induced by 45MV X-Ray is 6-8 times higher than it created from a conventional 6MV LINACs.2)the strongest distribution of Cerenkov emission spectroscopy is at 400-450 nm and its excitation efficiency for PpIX almost equal to 20 times of the efficiency at 630nm for the PDT.3)The inner homogenous Cerenkov emission excitation efficiency of RDT is 20 times of one-directional and exponentially exotic excitation efficiency laser of PDT.In addition,excite efficiency of the patented catalyst coenzyme on PpIX has a high-efficient effect(approximately 3-5 times).ConclusionsThe results indicate that excite efficiency for PpIX of Cerenkov emission from 45MV X-Ray is comparable with the excitation efficiency of the laser in PDT.RDT may be developed into a potential treatment modality for cancer in various stages and suitable for other diseases.