title: Differentiation of metastatic vs degenerative joint disease using semi-quantitative analysis with (18)F-NaF PET/CT in castrate resistant prostate cancer patients.
abstract: Fluorine 18 Sodium Fluoride ((18)F-NaF) (sodium fluoride) PET/CT is a highly sensitive but is a non-specific method for identifying bone metastases. Qualitative scan interpretation using low dose CT for lesion localization is often complicated by the presence of co-existing degenerative joint disease (DJD). A semi-quantitative analysis might help in accurately differentiating benign from metastatic osseous lesions. The aim of the study was to evaluate the clinical utility of (18)F-NaF PET/CT in differentiating DJD from metastatic disease in the skeleton using a qualitative analysis as well as a semi-quantitative approach using the SUVmax and to determine if there is an upper limit of SUVmax value that can reliably differentiate metastases from DJD. Baseline (18)F-NaF PET/CT scans were performed for 17 castrate resistant prostate cancer patients (CRPC). A qualitative as well as semi-quantitative analysis using maximum standardized uptake value (SUVmax) based on body weight was performed for 65 metastatic and 56 DJD sites identified on the low dose CT scan acquired as a part of whole body PET/CT scan. The SUVmax range in DJD was 2.6-49.9 (mean: 6.2). The SUVmax range for metastatic lesions was 11.2-188 (mean: 160). The SUVmax value for metastatic as well as areas of DJD showed significant variation during treatment. Bone metastases showed statistically significantly higher SUVmax than DJD using a mixed effect regression model. ROC/AUC analysis was performed based on averaging the SUVs over all lesions in each subject. The AUC was found to be fairly high at 0.964 (95% CI: 0.75-0.996). The SUVmax over 50 always represented a bone metastasis and below 12 always represented a site of DJD. The results of our preliminary data show that semi-quantitative analysis is complementary to the qualitative analysis in accurately identifying DJD from metastatic disease. The cut-off SUVmax of 50 can help in differentiating DJD from bone metastases.
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Saima
authors.initials: S
authors.lastname: Muzahir
authors.affiliation: Department of Medical Physics, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Jeraj
authors.affiliation: University of Wisconsin Carbone Cancer Center Wisconsin, Madison, Madison, WI, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Lance T
authors.initials: LT
authors.lastname: Hall
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Alejandro Munoz Del
authors.initials: AM
authors.lastname: Rio
authors.affiliation: Department of Medical Physics, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Perk
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Jaskowiak
authors.affiliation: Department of Radiology, Division of Nuclear Medicine, University of Wisconsin Madison Madison, WI, USA.
authors.forename: Scott B
authors.initials: SB
authors.lastname: Perlman
keywords: F-18 NaF; PET/CT; bone metastases; castrate resistant prostate cancer; degenerative joint disease