Correlation of PET standard uptake value and CT window-level thresholds for target delineation in CT-based radiation treatment planning

Conclusions: Our method of correlating SUV to W/L thresholds permits accurate displaying of SUV in coregistered PET/CT studies. The optimal SUV thresholds to contour GTV depend on maximum tumor SUV and volume. Best correlation occurs with SUVs >6 and small volumes <100 cc. At SUVs >7, differences between the SUV threshold filters remain constant. Because of variability in volumes obtained by using SUV40%Max, we recommend using SUV ≥ 2.5 for radiotherapy planning in non-small-cell lung cancer.