Report on the IPSM working party on low- and medium-energy x-ray dosimetry

New values of the factors required to convert the reading of a radiation dosemeter calibrated in terms of air kerma (or exposure) into absorbed dose to water for medium-energy x-radiation were given in a code of practice published by the IAEA in 1987. These are not considered to possess sufficient support from other sources. It is therefore recommended that the F-factors given in ICRU Report 23, and incorporated into the current HPA code of practice (1983), should continue to be used. Values of backscatter factors for low-energy x-radiation (below 140 kV or 10 mm Al HVL) in Supplement 17 of the British Journal of Radiology appear to be inaccurate. New values based on Monte Carlo calculations, and supported by new experimental data, are given for use in radiotherapy.