Implementing image-guided radiotherapy in the UK: plans for a co-ordinated UK research and development strategy

Abstract

Image-guided radiotherapy (IGRT) is a relatively new technology designed to improve the accuracy of radiotherapy treatment. It is used to improve the assessment of patient position, particularly taking into account organ motion caused by respiration and physiological emptying and filling of internal organs. This in turn permits accurate radiation dose delivery, with the aim of improving tumour control and reducing side-effects. The National Radiotherapy Advisory Group and the Academic Clinical Oncology and Radiobiology Research Network (ACORRN) identified a need for a national strategy to improve research and development in this area. ACORRN was awarded funding from the National Cancer Research Institute (particularly Cancer Research UK) to organize a national conference to identify the current status and research opportunities of IGRT in UK radiotherapy departments. In order to ensure that the day was as useful and informative as possible, ACORRN carried out an initial national consultation via their website (www.acorrn.org) to determine the particular needs of the radiotherapy community from this conference. Consequently, an interactive programme was developed to provide information and discussion about (i) the technologies used, (ii) priority clinical questions and (iii) potential clinical trials being undertaken. Over 130 clinicians, physicists and radiographers — representing 61 UK institutions — attended the conference on 11 September 2006 in the Royal College of Physicians (London, UK). Professor Steve Webb and Dr Phil Evans (Royal Marsden Hospital NHS Trust, London) gave an overview of IGRT, focusing on current practice within the UK. Having defined IGRT as all radiotherapy techniques that rely on the use of threeor four-dimensional images, they went on to outline when it can be used, the technologies involved and the associated problems. Table 1 details current IGRT techniques and their availability in UK radiotherapy departments. It was noted that those techniques not yet widely used in the UK are all used clinically in other countries, and therefore funding to enable physicists, clinicians and radiographers to visit centres abroad where these techniques are well established would be extremely beneficial. The example in which IGRT techniques were introduced to aid the delivery of proton and ion beam radiotherapy was cited [1]. The validity of using other workers’ evidence, as opposed to carrying out local clinical trials, was also raised. The consensus was that a new trial would be unnecessary when a new or changed practice is evidently worth implementing, as happened with treatment planning. For complex issues, such as the use of functional imaging in radiotherapy or intensitymodulated radiotherapy (IMRT) vs non-IMRT, the range of variables means that trials are probably more appropriate, particularly with legal frameworks that dictate exposure justification. However, it was suggested that identification of a hierarchy of fundamental and important questions to be addressed would be useful in assessing at which point a trial needs to be considered. Dr David Nicholas (The Cromwell Hospital, London) and Professor Chris Moore (Christie Hospital NHS Trust, Manchester) discussed in detail the advantages and restrictions of tomotherapy [2] and cone beam technology [3–5], respectively. Indeed, the ‘‘pros’’ and ‘‘cons’’ of all available imaging methods were discussed throughout the meeting, particularly with respect to the dose required, image quality and cost, in terms of equipment, extra treatment time and availability of skilled personnel. To obtain an image, MV and kV portal and CT imaging require finite doses, ranging from 0.2 cGy to 15 cGy per imaging session, depending on the desired quality; Address correspondence to: Academic Clinical Oncology and Radiobiology Research Network, c/o Christie Hospital NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, UK. E-mail: acorrn@manchester.ac.uk The British Journal of Radiology, 81 (2008), 379–382