Calibration of a whole-body counter suitable for use in routine clinical investigations

Abstract

The calibration of a clinical whole-body counter which utilizes a large area (60*40*10cm) detector is described. A simple counting technique minimizes the variation in response due to different distributions of radioactivity in the patient's trunk. Using this technique, the counter has been calibrated for a number of radionuclides (0.32 to 1.52 Mev) uniformly dispersed in a range of phantoms, and the errors involved in the use of this technique for non-uniform distributions have been estimated. In 63 measurements on patients given a variety of radionuclides, the calibration was accurate to 5% (standard deviation) even though, in many cases, the distribution of radioactivity in the body was grossly non-uniform.