The effect of the horizontal metallic drive on reference dosimetry in the SNC 3D scanner water tank.

The effect of the horizontal metallic drive on reference dosimetry in the SNC 3D scanner water tank. J Appl Clin Med Phys. 2020 Apr 01;: Authors: Aftab S, Barnes MP, Doebrich M, Lehmann J Abstract Accurate quantification of absorbed radiation dose is important for safe and effective delivery of radiation therapy. An important aspect to this is reference dosimetry, which is performed under reference conditions specified by international codes of practice. Such measurements are usually performed in a water phantom. In the Sun Nuclear Corporation (SNC) three-dimensional (3D) scanner water tank system the detector holder is fixed to a horizontal metallic drive rail (MDR) which is in close proximity to the active volume of the detector. In this project, the dosimetric effects of the MDR on reference dosimetry were investigated for MV photons, MeV electrons, and kV photons by comparing reference dosimetry measurements in the SNC 3D scanner against similar measurements in a Standard Imaging (SI) one-dimensional (1D) tank and against measurements in the SNC 3D scanner with an additional, custom-made spacer placed beneath the chamber holder to increase the chamber - MDR separation. A second experiment investigated the difference in chamber reading dependent on chamber to MDR separation by fixing the chamber in the tank independently of the MDR and successively moving the MDR vertically to alter the separation. The results showed that measurem...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research