Minimal Radiation for Families of Brachytherapy Patients

The research was conducted at the Washington University School of Medicine (St. Louis, MO, USA) and presented at the annual meeting of the Radiological Society of North America (RSNA) in Chicago (IL, USA).

The study involved 40 men, of whom 27 received iodine implants and 13 received palladium implants. All the men wore badges that measure radiation exposure in millirem (mrem) at their waists and necks. Family members who lived at home were given the badges to wear whenever they were with the men. Additionally, badges were placed in each main room of the house.

After three weeks, the results were extrapolated to determine what the exposure would be over the course of a year. Spouses of men in the iodine group received an average of 14 mrem, while other family members received less than eight mrem. Spouses of men in the palladium group received an average of 6 mrem and family members received virtually zero mrem. According to the U.S. Nuclear Regulatory Commission, the average person should avoid being exposed to more than 500 mrem a year from nonmedical or nonoccupational sources. The average person is exposed to 200-400 mrem a year. Both iodine and palladium have relatively short half-lives of 60 days and 17 days, respectively. After a year, there is very little radioactivity left in the implants.

"A person flying round-trip from New York to Tokyo will receive about 20 mrem,” noted Jeff Michalski, M.D., who made the presentation.