Quantitative and qualitative evaluation of density resolution of pCT images using Cirs062m phantom simulation in Geant4

Accuracy in the treatment planning (TP) of proton therapy (PT) depends on precision information employed to calculate relative stopping power (RSP) tissues patient's body. This is obtained from x-ray computed tomography (xCT) images and calibration curve needed convert Hounsfield unit RSP values. Using xCT bears errors range estimation dose calculation TP. Proton (pCT) can decrease inherent uncertainty PT by directly measuring RSP. Though using pCT integral mode energy loss, this error removed, map calculated directly. study simulated a modern imaging system with particle-by-particle tracking capability Geant4 Monte Carlo code. simulation sought improve density resolution tissue without increasing dose. The CIRS062M standard phantom was irradiated 300 MeV protons, energy, position, direction particle were recorded before after phantom. matrix image modified normalization algorithm amount loss correction angles projections.