Prospective evaluation of ^99mTc MDP scintigraphy, ¹⁸F NaF/¹⁸F FDG PET/CT and WBMRI in patients with breast and prostate cancers

Objectives We prospectively compared the combined NaF/FDG PET/CT and WBMRI against ^99mTc-MDP in patients with breast and prostate cancers.

Methods 15 men with prostate cancer and 15 women with breast cancer, 34-84 year-old (mean: 61±13), referred for ^99mTc-MDP bone scans were prospectively enrolled from Nov 2012 to Jul 2014. NaF and FDG were injected from separate syringes. PET/CT and MRI were done 1-21 days apart (mean: 2.5±3.9). WBMRI protocol consisted of T1-weighted, STIR, DWI, and contrast-enhanced T1-weighted imaging. Lesions detected with each test were tabulated and the results were compared.

Results 1 patient with a negative bone scan and PET/CT could not tolerate the WBMRI. 12 patients had no bone metastases identified on any of the 3 scans. Bone scan showed osseous metastases in 14 patients, while the combined NaF/FDG PET/CT and WBMRI showed bone metastases in 4 more and 3 more, respectively (18 patients total). More numerous bone findings were noted on PET/CT than on WBMRI in 7 patients. Lesions outside the skeleton were identified by PET/CT and WBMRI in 10 patients. In 1 patient MRI showed brain metastases not noted on PET/CT. In 1 patient PET/CT showed axillary and internal mammary lymph nodes not described on MRI.

Conclusions NaF/FDG PET/CT and WBMRI are superior to ^99mTc-MDP scintigraphy for evaluation of skeletal disease. Further, PET/CT and WBMRI detected extra-skeletal disease that may change the management of these patients. A combination of NaF/FDG PET and WBMRI may provide the most accurate staging of patients with breast and prostate cancers. Larger cohorts are needed in order to confirm these preliminary findings, ideally using the newly introduced simultaneous PET/MRI scanners.

Research Support GE Healthcare