Impact of Reducing Fluoroscopy Pulse Rate on Adult Modified Barium Swallow Studies.

Modified Barium Swallow Studies (MBSS) are a critical part of the evaluation, treatment planning, and outcome assessment for persons with swallowing disorders. Since MBSSs use ionizing radiation with associated cancer risks, many clinicians have reduced radiation exposure by reducing the fluoroscopic pulse rate. However, by reducing pulse rate, we also decrease the temporal resolution of MBSSs which has been shown in pilot studies to significantly reduce diagnostic accuracy. Two hundred MBSSs from patients routinely undergoing MBSS as standard of care conducted at 30 pulses per second (pps) using the Modified Barium Swallow Study Impairment Profile (MBSImP™) standardized administration protocol were selected. A stratified sampling method ensured that a full range of swallowing impairments (etiology, type, and severity) was represented. Recordings were down sampled from 30 pps to 15, 7.5, and 4 pps. MBSSs were rated using the MBSImP components and Penetration-Aspiration Scale (PAS) score for each swallow. Percent agreement was calculated across raters for MBSImP and PAS scores by bolus type and volume. The Least-Squares Method was used for hypothesis testing. Statistically significant and clinically meaningful changes in scores of swallowing physiology and penetration/aspiration occurred when reducing pulse rate below 30pps. These changes were evident across bolus types and volumes. Given the impact on diagnostic accuracy and the low radiation risks to adults undergoing MBSSs, reducing pulse rate to 15pps or below is not aligned with the As Low As Reasonably Achievable (ALARA) principle and should not be used as a viable method to reduce radiation exposure from MBSSs.