ALANINE DOSIMETRY OF PROTON THERAPY BEAMS

An analysis of some of the properties of the ESR-alanine dosimetry in therapeutic proton beams is reported. Thin alanine-based detectors (1 and 2 mm thick pellets and 0.25 mm thick films) were tested in a clini cal 62 MeV proton beam. The response of the alanine detectors in unmod ulated and modulated proton beams was studied in tissue equivalent pha ntoms. The dose assessed by alanine was compared to the dose provided by a Markus parallel plate ionization chamber, used for reference dosi metry. Experiments in the 5-250 Gy dose range showed linearity of alan ine dose response and no significant differences in the alanine respon se per unit dose to gammas and protons. Agreement within the experimen tal uncertainties was found between the alanine and the Markus chamber depth dose curves, including the Bragg peak region. (C) 1997 American Association of Physicists in Medicine.