Implementation of quality control devices for intraoperative gamma probe Preliminary results of performance tests

Abstract

In the last few years, the use of sentinel node technique has been increased; its success is connected with the proper performance of intraoperative gamma probes. This paper is focused on how to make performance and quality control tests to Europrobe S553U intraoperative gamma probe, from NEMA NU 3-2004 “Performance Measurement and Quality Control Guidelines for Non-Imaging Intraoperative Gamma Probes” normative, using devices designed for such purpose. Results of 11 performance tests are shown, which are between normal ranges previously reported in literature. Sensitivity values obtained in air are below of those obtained in a scatter medium, due to the collimation effect of the canon source. For all measured parameters, values with lower standard deviation belong to a distance of 30 mm between source and probe. Spatial resolution was (28,6±0,7)mm for a CdZnTe probe and (33,7±0,8)mm for a CsI one; best angular resolution in scatter medium was obtained for the first one of them (20,3±0,8degrees). A good energy resolution was obtained for CdZnTe detector (17kev of FWHM, for 99mTc). For periodic controls, an average activity of the punctual source around 0,74 MBq is suggested, in order to warranty a proper count rate, avoiding detectors saturation.