Purpose: The purpose of this study was to analyze the distribution of 18F Sodium Fluoride (18F-NaF) uptake in the normal skeleton, benign and malignant bone lesions, and extraskeletal tissues, using semiquantitative SUV measurements.
Patients and methods: We retrospectively analyzed data from 129 patients who had 18F-NaF PET/CT at our institution for an oncological diagnosis between 2007 and 2014. There were 99 men and 30 women, 19 to 90 years old (mean [SD], 61.5 [15.5]). The range, average, and SD of SUV were measured for normal bone and extraskeletal tissues uptake for the entire patient population. A separate statistical analysis was performed to compare group A, which corresponds to the population of patient with no 18F-NaF-avid metastatic lesions, and group B, which corresponds to the population of patient with 18F-NaF-avid metastatic lesions. We also measured SUV max and SUV mean for bony metastases and degenerative changes
Results: The PET/CT images were acquired at 30 to 169 minutes (mean [SD], 76.5 [22.8]) after injection of 3.9 to 13.6 mCi (mean [SD], 7.3 [2.4]) of 18F-NaF. The range and mean (SD) of SUV max for 18F-NaF-avid metastasis were 4.5 to 103.3 and 25.9 (16.6) and for 18F-NaF-avid degenerative changes were 3.3 to 52.1 and 16.5 (7.9), respectively.
Conclusions: Various skeletal sites have different normal SUVs. Skeletal metastases have different SUVs when compared with benign findings such as degenerative changes.