FIRST APPROACH TO 3D DOSIMETRY VERIFICATION USING LEKSELL GAMMA KNIFE (R) ICON (TM)

Gamma knife radiosurgery is a very precise method to treat the brain diseases. Since high energy gamma rays are very focused to the target accurate dosimetry solutions are mandatory [1]. Due to the steep dose gradients in the irradiation field close to the target, dosimetry method is required which provides information on 3D dose distribution and might be followed visually. Polymer gel dosimetry is the only method which fulfils these requirements [2]. Polymerized gels are sensitive enough to register absorbed doses in the wide range from starting from 0.1 Gy [3] to tens of Gy. According to the type of ionising radiation and target volume different formulations of dose gels are possible, however the quality of the final measurement result depends on the individual physical properties of dose gels, on accuracy and precision of gel dosimeters and their read out methods. The aim of this work was to initiate application of gel dosimetry for dose verification in gamma knife treatment.