The comparisons of the modalities of the irradiation on the radiation therapy by the analysis of the dose spectrum

The comparisons of some modalities of the irradiation on the radiation therapy by the analysis of the relationship between the dose level and the volume occupied by the dose range in three dimensional dose distribution are represented. The modalities of the irradiation are the opposed beams, three ports irradiation and the rotation therapy for the pinealoma, esophagus cancer and bladder cancer. The method of comparison is used by the ''Dose Spectrum'' and the ''Cumulative Dose Spectrum'' introduced by Konishi (1969). Three port irradiation is better modality than the rotation therapy for the cancer which is sorrounded by the large radiation sensitive tissue or organ such as esophagus Ca. or bladder Ca. nearby the lung or the intestines respectively by means of the analysis using cumulative dose spectrum. (author)