However, there are serious difficulties in the analysis of the clinical results so far. There are discrepancies in the recorded data, parameters are often defined differently, while data have been determined, recorded, reported and registered in dissimilar ways or incompletely. Parameters have been changed too frequently, usually several at once. Too many clinical, biological and physical parameters determine the cure rate and the failure of treatment, as well as the rates of early and late complication. Experimental data, if available, are not always applicable or comparable to the clinical situation.
Large centres tend to have a sufficient amount of data for internal studies.
They all try not to change any of the parameters if the treatments are succesful. The first step of this task group was to review all the work carried out till then. Retrospective evaluation is always unsatisfaying. Prospective studies are demanded. The aim of this TBI registry is then to allow a more precise knowledge of the influence of the dose, dose rate and fractionation, the relationship between TBI and Chemotherapy, the late effects in organs at risk such us lung, kidney, liver, central nervous system, etc.