Nuclear reaction data for radiation therapy - study on high energy photon and proton therapy

Nuclear reaction data has fundamental applications in Medical Radiation Therapy. Radiation therapy is based on the mechanism of energy loss in the medium, there by killing the cancerous tissues. Development of linear accelerators with high energy photon, electron and proton help in precession treatment. High energy Bremsstrahlung radiation in the energy range 4-15 MeV is routinely used for treatment. The energy loss mechanism before Bragg peak is not properly accounted in the dose calculations. Further, there is no benchmarked nuclear data available in the energy range of 100-300 MeV, and theoretical predictions are not being well tested. For the precise quantification of the absorbed dose and the dosimetric measurements, theoretical simulation of proton therapy is performed on the basis of computer code GEANT4. TENDL-2017 date base is taken for reference parameters. The data shows, an excess whole body dose is produced through the prompt gammas and neutrons through (p,xn) and (p,xg) reactions with naturally abundant isotopes of C, O, N, P, K etc. present in the normal tissue. Further the (p,el), (p,inl), (p,xd), (p,xa) etc. reduces dose conformity. This indicates the need of the benchmarked nuclear data for proton and heavy ion induced reactions, in the typical interest of radiotherapy. The dosimetric algorithm has to be updated and evaluated with caution