Evaluation of the minimum detectable activity in wholebody measurements of photo emitters

Abstract

Quality assurance in whole-body measurement includes quality control with procedure descriptions, detector calibrations, instrument control and evaluation internally or by outside persons. It is well know that some or several characteristics can be affected when the detector has been used in different energy radiation beams. A comparison and evaluation of the NaI(Tl) and HPGe based detector systems’ performances has been carried out at In Vivo Monitoring Laboratory of IPEN/CNEN-SP for measurements of elements used in radiopharmacy (131I, 123I and 99mTc) in chest regions. Alderson Research Labs. anthropomorphic phantom was used for the calibration. The concepts adopted in the HPS N13.30 Standard and proposed in ISO documents for standardization were used for activity measurements. Results of this comparison are presented together relative efficiencies and MDA values for all NaI(Tl) and HPGe based detector systems involved.