ABSTRACT
PURPOSE: To evaluate the response of MAGIC-f gel through dose response curves, percentage depth dose (PDD) and beam profile for clinical electron beams. METHODS: Glass tubes (Vacutainer ®), with 6 cm length and 0.5 cm radius, with MAGIC-f were positioned inside a water phantom to study the gel response with doses from 0.5 Gy to 20 Gy in electron beams of 6, 9 e 12 MeV. Glass tubes of 20 cm length and 1 cm radius and PMMA phantoms of 10 × 5 × 5 cm3 were used to PDD and beam profiles determinations, respectively, with a maximum dose of 2 Gy to the gel. The samples were analyzed through magnetic resonance imaging (MRI) with a 3 T tomography using a head coil, multiple spin echo sequence with 16 echos, TE 15ms and TR 4000ms. The MAGIC-f response was simulated with PENELOPE Monte Carlo code in the same geometry used in the irradiations. The results obtained with MAGIC-f and PENELOPE were compared with clinical data. RESULTS: Calibration curves for MAGIC-f showed a linear behavior, with correlation coefficient of 0.99, for all energies. The PDD and beam profile curves obtained with MAGIC-f presented differences lower than 1.5% and 3.0%, respectively, when compared to clinical data. Results obtained by PENELOPE and clinical data showed differences up to 1.0% and 1.5%, respectively, for PDD and profile curves. CONCLUSIONS: The dosimetric parameters for electron beams obtained experimentally with MAGIC-f and with PENELOPE code showed similar results to the clinical data. From the results it can be inferred that MAGIC-f can be used as a complementary dosimetric tool for electron beams due to its characteristics of high spatial resolution and the ability to construct tridimensional dose distributions. Also PENELOPE can be used to study MAGIC-f gel response in electron beams.