The effect of radiation on the permeability of human saphenous vein to 17 beta-oestradiol.
Radiation therapy is an effective way of treating many forms of cancer, however, there are some indications that it may facilitate the development of metastasis. The question arises whether radiation therapy during cancer treatment might result in an alteration of the permeability of the tissues being treated. This alteration in the permeability might lead to metastatic cells escaping from the irradiated tissue, leading to the spread of cancer to other sites in the body. Because of the above implication, we determined the diffusion kinetics of a radioactive marker, 17 beta-oestradiol, through human saphenous vein before and after a single half hour exposure to 60 Gy of 60Co gamma-irradiation. Six clinically healthy saphenous vein specimens (mean patient age +/- standard deviation 57 +/- 13 years; age range 41-77 years) were obtained during cardiac surgery. In vitro flux rates of 17 beta-oestradiol were determined through use of a flow-through diffusion apparatus immediately after irradiation for a period of 24 hours. No statistically significant differences could be demonstrated for the flux rates of 17 beta-oestradiol through the non-irradiated and 60 Gy irradiated saphenous vein tissue. These findings strongly suggest that irradiation at 2 Gy/min and a total dose of 60 Gy would not alter the permeability of the venous wall. We have demonstrated that the in vitro flow-through diffusion method is capable of measuring permeability aspects of endothelial cell layers in saphenous vein biopsies under conditions resembling clinical reality.