Chapter 84 - Operational Radiation Safety for PET-CT, SPECT-CT, and Cyclotron Facilities

Abstract

Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are, of course, well-established imaging modalities in modern clinical practice. Computed tomography (CT) scanners have been integrated into PET-CT and SPECT-CT devices, and these devices are dramatically impacting patient management. Short-lived fluorine-18 (18F)-fluoro-deoxyglucose (FDG) is, by far, the most widely used radiopharmaceutical for PET imaging in general and oncologic PET imaging in particular. Fluorine-18 as well as other radioisotopes used in PET such as carbon-11 (11C), nitrogen-13 (13N), and oxygen-15 (15O) are short-lived and produced almost exclusively in cyclotrons. The expanding role of PET in clinical practice has thus necessitated the widespread distribution of cyclotrons to provide these short-lived radionuclides locally. At the same time, the clinical application of combined single-photon emission computed tomography (SPECT) and CT has advanced as well, with the introduction commercially of SPECT-CT scanners. Cyclotron, PET-CT, and SPECT-CT facilities present complex but manageable radiationsafety challenges, but appropriate design and workflow can maintain staff exposures below, and generally well below, the applicable regulatory exposure limits. The current chapter surveys the radiation-protection aspects, in terms of both staff and general-public exposures, of medical cyclotrons, PET-CT, and SPECT-CT.