1. Attività WP8: sviluppo sistema dosimetrico INFN Firenze M. Bruzzi, M. Bucciolini, E. Pace, M. Scaringella, C. Talamonti, M. Zani, A. Baldi

2. Main Result: First large-area bidimensional map of dose measured with one 2.5x2.5cm 2 polycrystalline diamond under a IMRT beam for breast cancer on an area up to 14.4x10cm 2 b) -Premium Detector Grade polycrystalline diamond film ( Element Six, UK) 300  m thick; - Contacts produced by the University of Florence as Schottky barriers; -12 x 12 matrix, pixel size: 1.8x1.8 mm 2 - A custom printed circuit board designed and manufactured; - electronics read out applied with four 64 channels 20 bit current-input analog to digital converter chips (TI DDC264) able of measuring currents from fAs to mAs; - semi-rigid silver-silicone pin-contacts produced by us connecting each pixel of the 144 matrix connecting vias on PCB.

3. Current response of one pixel (V app = 1V) in a 10cmx10cm conventional 10MV X beam, showing stability and fast rise/decay times Charge response of the whole pCVD diamond matrix measured after irradiation with a X-6 MV beam conventional beam characterized by a 200 Mu/min dose rate. The map so obtained has been used to perform flatness corrections in successive IMRT measurements.

4. IMRT tests for prostate and breast cancer treatment performed in step-and-shoot modality IMRT breast cancer map as measured by the pCVD Diamond. IMRT breast cancer map as calculated by the TPS. (GT = gantry target direction; LL = lateral- lateral direction) Grid spacing is 3 mm.

5. Dose profiles and dose percentage difference gantry target (GT) direction lateral-lateral (LL) direction Experimental data in a good agreement with calculated ones. Dose differences with TPS in general within 3%, apart for a region of higher dose difference values, up to 8%, measured where the dose gradient is high. Results evidence the correct operation of the device, even considering that they are prone of alignment errors, as the whole map is obtained by shifting the device in the LL and GT directions.

6. Talks/Posters/Papers in 2014 Poster presented at IWORID, June 2014, paper accepted on JINST. Poster presented at RESMDD14, oct. 2014, paper submitted to Nucl. Instr. Meth. A.

7. Future developments (2015) Development of the electronic readout system Increase of active area up to 5.0x2.5cm 2 Tests under different IMRT / proton beams Study on single pad detectors to investigate how electrode geometry and detector thickness can influence the current response vs dose-rate dependence.