Histological studies after experimental grid irradiation vi. Findings on Guérin-tumours irradiated by high doses

Author demonstrated subsequent to high-dose grid irradiation in Guérin-tumours of the rat the histological grid pattern corresponding to inhomogeneous dose distribution. Two to four days after irradiation through the grid of narrow openings in some sites certain phenomena could be observed, which seem to refer to the severe damage acquiring a diffuse character, but after 7 days the histological grid pattern has been clearly defined and the severely damaged stripes were about 50 percent narrower than the relatively intact ones. On the basis of the results on the actual tumour and among the applied experimental conditions the existence of a specific grid-tumour effect could not be justified by histological methods.