Treatment Response Assessment of Skeletal Metastases in Prostate Cancer with F-NaF PET/CT.

PURPOSE

To determine the utility of F-sodium fluoride positron emission tomography-computed tomography (F-NaF PET/CT) in the imaging assessment of therapy response in men with osseous-only metastatic prostate cancer.

METHODS

In this Institutional Review Board-approved single institution retrospective investigation, we evaluated 21 F-NaF PET/CT scans performed in 14 patients with osseous metastatic disease from prostate cancer and no evidence of locally recurrent or soft-tissue metastatic disease who received chemohormonal therapy. Imaging-based qualitative and semi-quantitative parameters were defined and compared with changes in serum PSA level.

RESULTS

Qualitative and semi-quantitative image-based assessments demonstrated > 80% concordance with good correlation (SUVmax  = 0.71, SUVavg  = 0.62, SUVsum  = 0.62). Moderate correlation ( = 0.43) was found between SUVmax and PSA-based treatment response assessments. There was no statistically significant correlation between PSA-based disease progression and semi-quantitative parameters. Qualitative imaging assessment was moderately correlated ( = 0.52) with PSA in distinguishing responders and non-responders.

CONCLUSION

F-NaF PET/CT is complementary to biochemical monitoring in patients with bone-only metastases from prostate cancer which can be helpful in subsequent treatment management decisions.