Investigations into the profile of the density patterns produced by gallium 67 citrate in AS 30D tumours

The pharmacokinetic behaviour of Ga 67 was investigated on the basis of its in vivo distribution in rats that were tumour hosts. The following conclusions were drawn: 1. The affinity of Ga 67 to AS 30D tumours was regarded as being confirmed by the pronounced degree of density seen in the tumour a few hours after injection. 2. At 30 seconds after injection there was less accumulation in the tumour than in most of the organs. 3. The rate, at which Ga 67 was taken up from the blood into the organs and tumour was determined by capillary membrane permeability. 4. The fact that Ga 67 accumulates readily in numerous tumours is attributable to the presence of intracellular receptor sites for Ga 67. 5. A comparison with the distribution patterns produced by different technetium compounds suggests that it has less affinity for AS 30D tumours but is accumulated to a considerable degree in muscle and tumour tissue in general, although the corresponding retention times are limited. (TRV)