9 Reporting in Brachytherapy: Dose and Volume Specification

Reporting in Brachytherapy 157

1.2 The three levels of dose and volume evaluation for reporting Different levels of completeness and accuracy can be identified for reporting. Three levels have been identified for conventional photon beam therapy (44,47); they are proposed in the present report for brachytherapy (90) . Level 1 This implies reporting the minimum of data that are required to perform brachytherapy in an efficient and safe way. These data should be available in all centres, whatever their situation regarding staff and equipment. In well staffed and equipped centres, reporting at Level 1 may be sufficient for certain treatment techniques. In addition, reporting at Level 2 contains the information needed to perform a state of the art treatment. It allows the exchange of more complete and relevant information between different centres. The conditions for reporting at Level 2 usually require a well equipped and staffed centre. It implies that the relevant volumes (p. 158) and organs at risk (p. 163) can be defined with modern imaging techniques under reliable conditions (typically, a series of CT and/or MRI sections, but other imaging techniques, such as ultrasound or PET, may bring additional relevant information). At Level 2, it is also assumed that 3-D dose distributions are available; dose-volume histograms can then be derived from these two sets of information. Depending on local conditions, target and organ reconstruction is based on a full CT examination or a limited number of CT images (sections). Interpolation between images is therefore sometimes needed; the accuracy of the reconstructed target and organ dimensions depends on the number of sections available. Level 3 Reporting at Level 3 is characterised by individualised, usually very complex and often evolving techniques (e.g., “3-D image based intensity modulated brachytherapy”). Reporting at Level 3 contains all information from Levels 1 and 2. No additional reporting requirements are established yet, but comprehensive information should be given. All radiation therapy techniques are continuously evolving and more sophisticated equipment and software continue to be commercially available. Therefore, with time, the boundaries between the three levels, as defined above, may change. Level 2 Reporting at Level 2 must contain all the information of Level 1.