A study of target autoactivation for the monitoring of proton therapy

We began the study of the dose distribution confirmation in the patient body by using the β+ decayed nucleus that are produced from the target fragmentation with proton nucleus to target nucleus at the proton therapy facility, National Cancer Center (NCC), Kashiwa. The distribution of the β+ decayed nucleus is measured pair annihilation gamma rays from the nucleus by positron emission tomography (PET). As also the advantage of this reaction, the incident proton numbers are many than the incident carbon numbers for the therapy with once, because of the proton stopping power and relative biological effectiveness (RBE) differences with the carbon, moreover, the fragment cross section is large with from a few 10 mb to near 100 mb. Therefore, the produced β+ decayed nucleus number of the statistics can be increased. (author)