[Tridimensional radiation treatment planning].

The effectiveness of radiotherapy and the possibility that the patient will be cured are basically determined by the accuracy of the therapy planning and the treatment. The tumour with its environment is a three-dimensional (3D) phenomenon, and therefore 3D radiation treatment planning and performance are needed for adequate coverage of the target volume (tumour+safety zone). The prerequisities of the elaboration of the 3D radiotherapy planning were as follows: the availability of high-performance hardware, the establishment of interactive computer graphics, and the development and direct integration into the therapy planning process of the digitalized information derived from diagnostic imaging, and especially computer tomography. The introduction of 3D treatment planning will mean the modernization of the radiotherapy, the accuracy of which may permit more cures, i. e. more patients will recover their ability to work.