Dosimetric characterization of a rigid, surface-contour-specific thermoplastic bolus material.

A dosimetric analysis of a commercially available thermoplastic sheet bolus, Klarity EZ Bolus, was completed. Attenuation characteristics were evaluated using different configurations of a rectilinear water-mimicking plastic phantom irradiated by a high-energy linear accelerator using three photon energies, five electron energies. These results were compared with data obtained during the linear accelerator commissioning process to determine depths of water that attenuated beams similarly. CT scans of the flat, unmolded sheet bolus, as well as of the bolus molded to a cylindrical phantom, were analyzed. The product was found to form a durable and rigid, contour-specific bolus with a water-equivalent thickness of approximately 6 mm for a single sheet, and 11 mm for two sheets in tandem.