Response of the alanine radiation dosemeter to high-energy photon and electron beams

Alanine dosemeters were exposed to beams of 4, 8 and 16 MVp X-rays and 6, 8, 10, 12, 14, 17 and 20 MeV electrons from linear electron accelerators used for radiation therapy. Dose levels used were 100 Gy or below. The theoretical energy dependence of the dosemeters was calculated for photons and electrons. After correction for theoretical energy dependence, the response of the dosemeters had a coefficient of variation of 0.4% around the average value. The average response was within 1% of the response of the alanine dosemeters exposed to a 60Co-γ ray source or a 137Cs-γ ray source, both calibrated with ion chambers. The dosemeters were used as an independent check of the output calibration of a linear accelerator before clinical use. Absorbed dose of the dosemeters was determined by comparison with those exposed to a 60Co-γ ray source calibrated with Fricke dosimetry. Deviation between the ion chamber and alanine dosimetry was less than 1%. (author)