Efficacy of MOSkins in BreastCT Dosimetry

MOSkin is a radiation detector that is equipped to output the dose at the surface of the skin during radiography and radiotherapy procedures. With the commencement of the clinical trials using Synchrotron based computed tomography (CT) imaging for the breast, MOSkins are characterised for their energy dependence with Synchrotron mono-energetic beams, calibrated respective to PTW ionisation chambers. MOSkins are energy dependent at energies <100keV and requires energy correction of the calibration factor (Gy/V). For a synchrotron CT, using an ellipsoid gelatin breast phantom, MOSkin results show a 3x more dose delivered at the entry of the breast compared to the centre, with a decrease in entry dose once as the energy increases once normalised to the centre dose in the breast. Simulation results generated from GEANT4 using Livermore Physics present us with the same trends and results within error. MOSkins can be used to determine breast imaging doses with an energy-calibrated correction factor. Correct entry dose measurements for imaging beams and synchrotron CT beams ensure dose-tissue tolerances are met for radiosensitive breast tissue in clinical trials.