Electron dosimetry intercomparison in UK radiotherapy centres

The Institute of Physical Sciences in Medicine (IPSM) have been funded by the UK Department of Health to carry out a national electron dosimetry intercomparison involving all radiotherapy centres in the country possessing electron beam treatment facilities. This will incorporate an overall audit of electron dosimetry, beam energy and procedures and is a follow up to the previous UK megavoltage photon dosimetry intercomparison (Thwaites et al. Phys.Med.Biol. 1992, 37:445). The aims of the project are to develop a methodology for clinical electron dosimetry audit and, using this, to collect data on a national scale to quantify the consistency in current UK practice. The results should identify problems in practices and encourage improvements in quality and will provide a standard baseline set of data against which individual centres can judge their performance and upon which ongoing routine audit of electron beams can be based. A number of these radiotherapy centres have also recently participated in an IAEA/WHO postal TLD based electron dosimetry intercomparison. The two different methodologies employed are described and preliminary results from the two studies compared