[Importance of the tumor duplication time for the clinical radiotherapy (author's transl)]

Malignant tumors of man have duplication times ranging between few days and several years. This fact allows to estimate the age of tumor and metastases. The decision whether a curative of a palliative irradiation is to be executed can be taken according to the development and the age of the tumor. The duplication time has an influence on the fractionation of the irradiations and the possible focal dose and also on the time after which check-up examinations are to be made. A method for the determination of the tumor volume by means of radiographs is described in the appendix.