There is a need for stable gel materials for phantoms used to validate optical CT scanners for the evaluation of radiotherapy gel dosimeters. Phantoms have previously been proposed based on addition of food coloring dyes to gelatine to simulate polymer gels. However, because optical extinction in these dyes operates via light absorption, they would be more suitable for simulating radiation sensitive radiochromic dosimetry gels in which the exposed region of the gel becomes more optically absorbing. To correctly simulate polymer type gels which operate via light scattering, it would be more realistic to add light scattering centers such as colloidal suspensions (sols) to the gels used in such phantoms. In this paper we present some of the results of the evaluation of a Vista optical CT scanner (Modus Medical Devices Inc.) using novel gel phantoms in which radiation exposed polymer gels are simulated by the addition of largely colorless sols of varying turbidity.
|Conference||World Congress on Medical Physics and Biomedical Engineering|
|Period||27/08/06 → 1/09/06|