A semi-empirical model for the therapeutic range shift estimation caused by inhomogeneities in proton beam therapy.

The purpose of this study was to devise a simple semi-empirical model to estimate the range shift in clinical practices with high-Z inhomogeneity in proton beam. A semi-empirical model utilizing the logarithmic dependence on Z in stopping power from Bohr's classical approach has been developed to calculate the range shift due to the presence of inhomogeneity. Range shift from metallic plates of atomic number Z of various thicknesses were measured in water using a parallel plate ionization chamber and calculated with the FLUKA Monte Carlo code.

Dosimetric characteristics of a single use MOSFET dosimeter for in vivo dosimetry in proton therapy.

Purpose: Entrance dose (or skin dose) is an important part of patient quality assurance in external beam radiation therapy. However, entrance dose verification in proton beam is not routinely performed. In this study, the OneDose single use MOSFET detector system for in vivo dosimetry measurement in proton therapy is investigated.