[Experience with the conversion from radium therapy to an afterloading procedure with special reference to spatial dose distribution].

In radium therapy, the spatial and temporal dose distribution have never been identical in the different hospitals. However, the healing results did not vary correspondingly despite the partly great methodical differences between German and foreign hospitals. Furthermore, the spatial and temporal dose distribution in radium therapy did not conform to theoretic considerations but were a result of the low specific activity of radium as well as of the technical standard of X-ray therapy units until the sixties. It is shown that all requirements valid for radium therapy are also fulfilled by the afterloading method using a linear ray emitter, if an adequate dosage and fractionation is chosen. Taking into account the radiation risk, we think that the radium must be replaced by an afterloading method using a less dangerous nuclide. In our opinion the high dose rate technique is the most favorable method.