Positron Emission Tomography-Computed Tomography Standardized Uptake Values in Clinical Practice and Assessing Response to Therapy

The use of standardized uptake values (SUVs) is now common place in clinical 2-deoxy-2-[18 F] fluoro-D-glucose (FDG) position emission tomography-computed tomography oncology imaging and has a specific role in assessing patient response to cancer therapy. Ideally, the use of SUVs removes variability introduced by differences in patient size and the amount of injected FDG. However, in practice there are several sources of bias and variance that are introduced in the measurement of FDG uptake in tumors and also in the conversion of the image count data to SUVs. In this article the overall imaging process is reviewed and estimates of the magnitude of errors, where known, are given. Recommendations are provided for best practices in improving SUV accuracy.