Is there a specific SUV threshold on FDG PET that can reliably distinguish malignant from benign disease processes?
No, there is no one particular SUV threshold level that can reliably distinguish malignant from benign lesions on FDG PET. SUV measurements are affected by the scan acquisition parameters utilized, the delay time between FDG administration and image acquisition, and patient body size and thus will vary somewhat from patient to patient and from scan to scan. Furthermore, SUVs will generally appear to be lower for small lesions compared to those of large lesions due to the limited spatial resolution of PET (i.e., the partial volume effect), leading to underestimation of FDG uptake in small lesions. Lastly, as described above, some indolent tumors may have minimal or no FDG uptake, whereas infectious or noninfectious inflammatory lesions may have increased levels of FDG uptake similar to malignant tumors.