Modified Barium Swallow Studies (MBSSs) are a fluoroscopic exam that exposes patients to ionizing radiation. Even though radiation exposure from MBSSs is relatively small, it is necessary to understand the excess cancer risk to the patient, in order to ensure a high benefit-to-risk ratio from the exam. This investigation was aimed at estimating the excess radiation risks during MBSSs. We examined 53 adult MBSSs performed using the full Modified Barium Swallow Impairment Profile (MBSImP) protocol. For each exam, the radiation dose (in terms of dose area product), patient age, and sex was recorded. Using published methodology, we determined the effective dose and organ specific dose then used BEIR VII data to calculate the excess cancer incidence related to radiation exposure from MBSSs in adults. Excess cancer incidence risks due to MBSSs were 11 per million exposed patients for 20-year-old males, 32 per million exposed patients for 20-year-old females, 4.9 per million exposed patients for 60-year-old males, and 7.2 per million exposed patients for 60-year-old females. Radiation exposure to the thyroid, lung, and red bone marrow contributed over 90% of the total cancer incidence risk. For the 20-year-old males, the excess cancer incidence risk is 4.7%/Sv, which is reduced to 1.0%/Sv in the 80-year-olds. For the 20-year-old females, the excess cancer incidence risk is 14%/Sv, which is reduced to 1.3%/Sv for 80-year-olds. Overall, the risk per unit effective dose from MBSSs is lower than the risk estimates for uniform whole-body irradiation. Patient age is the most important determinant of patient cancer risk from MBSSs.
Keywords: Cancer risks; Deglutition disorders; Fluoroscopy; Radiation exposure.