REAL-TIME, IN-VIVO MEASUREMENT OF RADIATION-DOSE DURING RADIOIMMUNOTHERAPY IN MICE USING A MINIATURE MOSFET DOSIMETER PROBE

This report presents the first real-time measurement of absorbed radia tion dose during radioimmunotherapy in mice. Dose rate and total dose at the center of the tumor were measured after administration of Y-90- labeled antibodies using a miniature metal oxide semiconductor field-e ffect transistor radiation dosimeter probe which was inserted into the center of the tumor volume. Continuous real-time measurements were ma de for as long as 23 h after injection of the radiolabeled antibodies. Comparison of the real-time dose-rate measurements with estimates bas ed on the MIRD formalism indicates good agreement. The real-time measu rements are further compared to measurements made in a second experime nt in which groups of mice were sacrificed at individual times after i njection of the same radiolabeled antibodies. The real-time measuremen ts agree well with the measurements in excised tumors. The real-time m easurements have greater time resolution and are much more efficient t han traditional uptake measurements. (C) 1995 by Radiation Research So ciety