Proton therapy dosimetry using the scintillation of the silica fibers.

Abstract

We investigate the feasibility of proton therapy dose measurement by using scintillation of a bare silica glass fiber. The emission spectra of the optical fiber at various depths in tissue-mimicking phantoms, irradiated with proton beams of energies 100-225MeV show two distinct peaks at 460 and 650nm whose nature is connected with the silica point defects. Our experimental results and Monte Carlo simulation showed that the Čerenkov radiation cannot be responsible for such a phenomenon. We showed that the intensity of the peak at 650nm correlates with the proton dose with a minimal effect of ionization quenching, while the intensity peak at 460nm under-reports the radiation dose.