Geant4 - Study of Dose Curve Parameters of Tumor in Human Tissues Using Passive Proton Beam

A detailed Geant4 based study of the proton beam passing through different Inhomogenities in a human phantom is carried out. Whenever a proton beam is radiated through the tumor region a significant influence over the stopping power and the depth-dose distribution of the proton energy can be observed due to the adjacent materials. The effect of the heterogeneous medium in tumor has been studied by several groups to assess the ability of beam convolution which predicts the dose required. Adipose, bone and soft tissues materials are considered for the present study. The human organs along with the positioning of the tumor region were designed. The suitable energy range for each tumor of the human organ was optimized. The study was also followed with thickness variation of each material from 0.1 cm to 1.0 cm. Various parameters of the Bragg curve were computed i.e. Bragg peak position, range, penumbra width, full width at half maximum and dose of Bragg curve. A significant shift in the Bragg peak position is observed in each case i.e., Approx.-0.36% for muscular skeleton, -0.44% for soft tissue.