Thank you Lisa for your experiences. I am writing on behalf of my hubby that out of the blue found out 3 years ago (October), that he had lung cancer in both his lungs with a different cancer in each lung, and a non smoker. He has had quarterly contrast ct scans and we know the contrast gets filtered through the kidneys each time and I guess my reason for asking the long term effects of these dyes going through your system. Radiation is of course another cause for concern as too much can actually bring on cancer, so a lot on our plate to handle with age also a factor.