A solid water phantom material for radiotherapy x-ray and γ-ray beam calibrations

Abstract

The formation, manufacture and testing of an epoxy resin-based solid substitute for water is presented. This solid water has radiation characteristics very close volumetrically to those of water. When it is used as a dosimetry phantom for X- and .gamma.-ray beams in the radiotherapy range, phantom-to-water corrections and density corrections are eliminated. Relative transmission measurements have shown that the transmission through 10 cm of solid water is within 0.2% of that through an equal thickness of water for X- and .gamma.-rays. The use of this material for calibration phantoms can help achieve the goal of radiotherapy beam calibrations within .+-. 1.0% of the true dose rate, easier to achieve.