After the pioneering work of HOFFER et al. on fluorescent scanning of natural iodine in the thyroid, several authors have suggested the use of X-ray fluorescence analysis to follow in vivo the distribution and elimination of stable tracers injected prior to the investigation. The normal method of performing such studies is to inject iodine containing contrast media and then follow the variation in iodine concentration by in vivo measurements over the organ or tissue of interest.A theoretical treatment of the application of X-ray fluorescence in in vivo studies has been made by TINNEY by means of analytical calculations.
A Monte Carlo study on the feasibility of real-time in vivo source tracking during ultrasound based HDR prostate brachytherapy treatments