Complex field verification using a large area CMOS MAPS upstream in radiotherapy

Abstract A multileaf collimator (MLC) is an integral component in modern radiotherapy machines as it dynamically shapes the photon field used for patient treatment. Currently, MLC leaves which collimate treatment are mechanically calibrated to ±1 mm every 3 months and during pre-treatment calibration set leaf positions. Leaf drift can occur between dates hence exceed tolerance. Pre-treatment verification, increases LINAC usage time so seldom performed each individual treatment, but instead acceptable sample of patients and/or fractions. Independent real-time verification therefore desirable. We developing a large area CMOS MAPS upstream monitor positions verification. radiation hard electron irradiation, have high readout speeds low attenuation makes them ideal detector radiotherapy. Previously, we reported on position reconstruction single using Lassena, 12 × 14 cm 2 , three side buttable suitable clinical deployment. Sobel operator based methods were edge reconstruction. It was shown that correspondence reconstructed excellent resolutions ranged 60.6 ± 8 109 μm central with extensions ranging from 1 35 0.3 sec beam at 400 MU/min. Here, report updated complex configurations, use. Results show be 62 6 86 16 adjacent isocenter 0.15 MU/min beam. These significantly better than current standards.