[The concept of target volume of radiotherapy (authors transl)].

It is emphasized to apply the prescribed target dosis not for a single point but in every case for a determined size and volume of the target. This is the target volume, wherein the ordered radiation dose should be applied. The absorbed dose within the target volune should as a rule be given as homogeneously as possible with a standard deviation not greater than +/- 10%. Application of target volume concept is discussed with regard to some special examples (nasopharynx, kidney, gynecological tumours). The target volume is a good basis for optimization of radiotherapy and development of criteria. This is also true for combination of radiotherapeutic methods in gynecological carcinomas. It is mandatory to make full use of the determination of the target volume concept for every single patient, if radiotherapy planning with or without computer has to be performed.