Abstract

Aims: This work is intended to establish the effect of ambulatory patients undergoing positron emission tomography (PET) imaging on a sensitive gamma counter that is located within the nuclear medicine department and used for in-vitro tests in the department. Methods: The effect on gamma counts recorded by a stationary 68Ge positron source and of a PET patient (100 minutes post injection of 550 MBq 18F-2-deoxy-D-glucose) walking past the Perkin Elmer WIZARD2 2470 gamma counter's shielded laboratory was measured. Further tests using uniform 68Ge sources both inside and outside the gamma counter laboratory were performed with a 99mTc glomerular filtration rate gamma counting protocol. Results: The stationary 68Ge sources could be detected by the gamma counter during both a GFR counting protocol and an open energy window protocol at all distances tested, both inside and outside of the shielded laboratory. A single PET patient walking past the laboratory had a negligible effect on an open counting window. Conclusions: The potential effects of PET patients on the WIZARD2 gamma counter can be mitigated by ensuring these patients are encouraged to exit the department after their scan without lingering outside the shielded laboratory in the Nuclear Medicine department.