Posted on 15 September 2014
CEA LIST’s national metrology lab for ionizing radiation, LNHB (Laboratoire national Henri-Becquerel), has established a dose profile protocol using EBT3 Gafchromic films to improve the absolute measurement of doses in mini-beam radiotherapy. These latest-generation films make it possible to directly obtain a 2D map of the dose delivered with high spatial resolution.
LNHB compared the dose profiles obtained with results from other detectors (diamond sensor and ionization chamber) and with Monte Carlo simulations. All of the results were consistent, demonstrating the effectiveness of EBT3 Gafchromic films.
To further enhance the analysis, additional measurements will be taken. For example, LNHB researchers will perform a more thorough analysis of the dosimeters’ response (such as energy dependence).
The next step will be to validate the approach for one-point dose measurement with the GR11 large-sized graphite calorimeter and compare the results with a conventional reference dosimetry for 2-cm-diameter irradiation fields. The ultimate goal is to apply this dosimetry method to mini-beams with diameters of less than 1 cm.
