Stability and Influence of Dose Rate in the Signal Response of the Alanine Gel Dosimeter

Nowadays, the three dimensional (3D) dosimetry has been studied by many researchers for application in radiotherapy and radiosurgery treatments, because this kind of dosimeter enable to evaluate the 3D dose distribution. The alanine gel dosimeter was developed at IPEN to be applied to 3D dose evaluations using magnetic resonance imaging. This dosimeter is a gel material based on the transformation of the ferrous ions in ferric ions, which presents significant improvement on previous alanine systems developed by Costa (1994). The DL-Alanine (C3H7NO2) is an amino acid tissue equivalent that improves the production of ferric ions in the solution. The ferric ions concentration can be measured by spectrophometry technique. This work aims to analyse the stability and influence of the dose rate in the optical signal response of alanine gel dosimeter, since these two properties are very important for characterization and standardization of any dosimeter.