Anwendung kerntechnischer Berechnungsmethoden für Gammastrahlen bei der Bestrahlungsplanung

Summary

Computer programs have been developed in recent years for the design of nuclear reactors with improved shielding; these can be applied in radiology to provide a theoretical basis for earlier experimental work and semi-empirical methods.

The Stuttgart PLK program, originally developed to determine heat sources and equivalent doses of mixed neutron and gamma radiation, was adapted to enable calculation by computer of the production of secondary electrons by gamma radiation in the tissues. Where penetration of secondary electrons can be neglected (X-ray and ⁶⁰Co radiation), the desired local distribution of the energy dose is found directly; where it cannot (betatron gamma radiation), the necessary information about the source of secondary electrons is obtained. Three examples are given to illustrate the efficiency of the method: a layer of homogeneous tissue, thigh and head irradiation. Hard and soft X-rays, cobalt gamma rays and betatron bremsstrahlen were programmed at energy maxima of 10, 30 and 50 MeV.