HIGH-TECHNOLOGY TO SIMPLIFY THE PLANNING AND DELIVERY OF RADIOTHERAPY

Two techniques for the automatic selection of individual leaf position s of a Philips multi-leaf collimator are described. Target volumes are identified either on simulator images or on cross-sectional images fr om CT or MR scanners. The setting of each leaf is computed to position the beam edge to cover the target with an appropriate, user defined, margin. An important consideration in the development of the system wa s its robustness and so the applications initially implemented have be en relatively simple, comprising single field, parallel opposed fields and coplanar 4 field box techniques. Attention has been paid to the o verall integrity of the planning and treatment delivery process. Befor e treatment commences, the beam shapes, which have been generated by t he computer and transferred to the MLC control computer over a local a rea network, are checked against a printed template representing each beam. All data used for planning is archived and is accessible for rev iew or, if necessary, for treatment modification.