[Optimization of reproducibility of irradiation fields with particular reference to irregular fields (author's...

Optimum reproducible planning is one of the aims of radiation therapy. Distribution of dosage can be calculated very accurately with the help of presently available planning facilities. It was the purpose of this study to find out how accurate the initial adjustment of the therapeutic device can be. For this purpose, 1806 control x-ray films were evaluated. The initial correction quota was about 27%. The second part of the study dealt with reproducibility of field adjustment. Series of x-ray films recording the course were prepared with verification films; the resulting field distributions were calculated on the basis of these films, and compared with the planned fields.