Application of MOSkin detector for in vivo dosimetry on total skin electron therapy (TSET)

Currently, TLDs and Gafchromic EBT3 film are commonly used for skin dose measurement during Total Skin Electron Therapy. However, measurements using these dosimeters are time consuming due to post-irradiation processing requirements. The MOSkin has advantages of being a small physical size with a 0.55 μm thick gate oxide and a water equivalent depth of 0.07 mm while providing real-time dosimetry. Measurements of the MOSkin's dosimetric characteristics were performed using a 6 MeV electron beam with an Elekta Infinity linear accelerator. For the TSET measurements, doses measured with the MO Skin were directly compared to TLDs and Gafchromic EBT3 film using a 6 MeV high dose rate electron beam. A 6 mm Perspex spoiler was placed and aligned perpendicularly to the beam in order to lower the effective beam energy and improve dose homogeneity. The MO Skin showed good dose linearity (R² = 0.9986) and dose rate independence for a 6 MeV electron beam and behaved very similarly to the other types of dosimeters that are commonly used in vivo dosimetry. For the TSET measurements, all three detector types showed a very similar trend of dose readings over the range of measurement points. Therefore, the MOSkin is an effective skin dosimeter for TSET dosimetry. (author)