The value of quantitative analysis in 18F-NaF PET/CT

Abstract Aim To evaluate the ability of SUVmax to differentiate bone metastases from degenerative lesions, blastic from lytic metastases, as well as to determine the correlation between SUVmax with 18 F-NaF and with 18 F-FDG. Material and methods A review was performed on 115 18 F-NaF PET/CT studies. Of the 64 patients with bone metastases, 49 (39 women, 10 men, 61 ± 12 years (16–81)), in whom the PET/CT supported the diagnosis of bone metastases, were selected for analysis. A record was made of the SUVmax of a maximum of ten metastases in each patient (total 172: 141 blastic, 31 lytic), as well as four degenerative lesions (total 188) with the greatest 18 F-NaF uptake intensity. Of the 49 patients analyzed, 43 also had a 18 F-FDG PET/CT performed in which a record was made of the SUVmax values for 18 F-FDG calculated in the locations corresponding to the bone metastases observed in the 18 F-NaF PET/CT: 128 metastases (106 blastic, 22 lytic). Results The mean of the SUVmax values was significantly higher in metastases than in degenerative lesions, 26.8 ± 17.3 vs . 15.3 ± 6.3 ( P  vs . 22.1 ± 11.3 ( P  = 0.03). A SUVmax value above 42 always represented metastases, with all values above 49 representing blastic metastases. Using the SUVmax values, it was possible to predict the occurrence of metastases (AUC = 0.723; P 18 F-NaF was significantly higher in blastic metastases (27.9 ± 18.3 vs . 22.1 ± 11.3, P  = 0.03), whereas with 18 F-FDG it was significantly higher in lytic ones (3.9 ± 3.4 vs . 9.6 ± 3.3; P Conclusions SUVmax can contribute to the differentiation of metastases from degenerative lesions, and blastic from lytic metastases.