Abstract
Properties of carbon fibre of relevance to its use for megavoltage radiotherapy applications have been investigated. Measurements have been made of the percentage transmission and percentage build-up of carbon fibre at energies of 5, 6 and 8 MV. The results are presented in comparison with those obtained for other materials commonly used in radiotherapy: polymethylmethacrylate (PMMA), PETG copolyester and expanded polystyrene foam. It was found that carbon fibre has a higher percentage transmission and a lower percentage build-up than either PMMA or PETG copolyester. It was also found that the build-up due to a combination of carbon fibre and 5 cm of polystyrene foam was less than 65% over the energy range for which measurements were made, and much lower than that due to PETG copolyester. It is thus proposed that carbon fibre is a suitable material from which to make devices for use in megavoltage radiotherapy.