Single peak analysis of proton induced prompt gamma counts.

• Geant4 simulation of proton induced prompt gamma spectra of most abundance elements of human tissues. • Single peak analysis is applied on prompt gamma spectra for determining mass of elements in irradiated phantoms. • A new approach is proposed to deal with similarly found gamma-ray peaks related to multi elements. • The estimated mass of elements are in good agreement with predefined values. • The effect of estimated mass errors on calculated proton range is small. Online elemental analysis of irradiated tissues is an important challenge in proton therapy for estimating the depth of the Bragg peak and monitoring the healing process. In the present study, the prompt gamma (PG) spectra of the most abundant elements of human tissues were obtained for two different incident protons of 30 MeV and 120 MeV using the Geant4 toolkit. Train phantoms were defined to study the elemental analysis of the tissue from PG spectra. It was found that the intensities of 7.12 and 3.91 MeV PG depend on the mass of 16O and 20Ca elements for both proton energies, respectively. Furthermore, multi-variable linear functions were presented for overlapping peaks like 4.44 and 2.31 MeV PG lines. The results show that the relative errors of estimated masses relative to predefined values are small and the corresponding errors in the proton range are less than 4.5% for test phantoms. [ABSTRACT FROM AUTHOR]