The successful use of ionising radiation to treat cancer depends crucially on the ability to maximise the radiation dose to the tumour whilst minimizing the dose to healthy surrounding tissue.

Many of the recent advances in radiotherapy are based on improvements in the ability to target dose on to the tumour volume, either by the use of multiple external radiation beams or by introducing sources internally close to the tumour. This talk will concentrate on one of the newest techniques, tomotherapy, in which many narrow external beams are used in conjunction with imaging techniques to produce a high degree of dose localisation. This method of dose delivery is far removed from the uniform static fields traditionally used for dosimetry and this has led NPL to develop specialised measurement techniques to ensure accurate and traceable dosimetry for these treatments.

Peter Sharpe joined NPL in 1975 with a PhD in radiation chemistry from the University of Manchester. He has worked on many radiation dosimetry projects, mainly related to the use of chemical dosimetry techniques in industrial and medical applications. Peter is also heavily involved in international standards activities and the development of industrial radiation processing standards through ASTM and ISO. He is a member of the BIPM Consultative Committee on Ionising Radiation and chairman of the Section dealing with radiation dosimetry.