DEAR DR. ROACH: Due to a slight genetic risk of breast cancer (my Tyrer-Cuzick Model score was 20.6%), my doctor wants me to get breast MRIs with contrast annually. I am concerned about long-term exposure to the gadolinium-based contrast dye. I’ve learned that this heavy metal is considered safe, but traces of it can be stored in the brain and other body tissues.
I am 49 and in very good health. I also get mammograms annually. I consulted my doctor about spacing out my MRIs to every two to three years, but he said I should have an MRI every year. So I could be getting these MRIs for the next 35 or so years. Do the benefits of contrast dye outweigh the harm in a person with my health profile? — S.A.
ANSWER: I’m afraid I don’t have a good answer for you. It is true that most authorities recommend an intensive breast cancer surveillance program for women at a high risk of breast cancer in the range of a 20% to 25% lifetime risk. (The average risk for developing breast cancer for a woman born today is estimated to be about 13%.)
The Tyrer-Cuzick model of estimating breast cancer risk tends to give higher estimates than the other commonly used models, such as the BRCAPRO. Other models may not put you over the threshold for intensive screening with MRIs, which is usually combined with mammogram.
The question about gadolinium (the chemical element used in the contrast dye for MRIs) is important because some people do store gadolinium in various tissues, including the brain, but the clinical significance of this is unknown. (People with kidney disease can develop a skin disease due to gadolinium, and so they are not recommended to have MRIs with gadolinium.)
Although gadolinium can stay in the body for months or years, there has been no evidence of harm from gadolinium in brain tissue, despite these agents having been used for many years. Some agents have less retention than others. The U.S. FDA has mandated patient guides for these contrast agents, which relay the above information.
Given that there is a probable benefit to intensive screening for breast cancer in your case, due to your high genetic risk, and no more than a theoretical risk from gadolinium, I believe that the benefits outweigh the risks, but I can’t say that with complete certainty.
