18F-Fluorocholine PET Whole-Body MRI in the Staging of High-Risk Prostate Cancer

The purpose of this study was to determine whether integrated 18F-fluorocholine (FCH) PET whole-body MRI (PET/WBMRI) depicts lymph node and distant metastases in patients with high-risk prostate cancer more frequently than does conventional staging.

A prospective study included 58 patients with untreated high-risk prostate cancer. After conventional staging (CT and bone scintigraphy), patients underwent FCH PET/WBMRI (n = 10) or FCH PET/CT and WBMRI (n = 48). Metastatic sites and disease stage were recorded for each modality (conventional imaging, PET, WBMRI, and PET/WBMRI) and compared with a standard of reference (histopathologic examination, imaging, and clinical follow-up) and early clinical outcomes.

In the detection of metastases, PET had significantly higher sensitivity (72/77 [93.5%]) than conventional imaging (49/77 [63.6%]; p < 0.001) and WBMRI (56/77 [72.7%]; p = 0.002). There was a trend toward improved detection with PET/WBMRI (77/77 [100%]) compared with PET alone (p = 0.059). For correct NM staging, PET and PET/WBMRI performed better than conventional imaging (p = 0.002) and WBMRI (p = 0.008). Twelve of 56 patients (21.4%) had early biochemical failure after radical treatment (median, 7 months; range, 1-20 months). This rate was higher for patients with M1a or M1b disease at PET/WBMRI than for others, but this finding did not reach statistical significance (4/8 [50%] vs 8/48 [16.7%]; p = 0.055).

In patients with high-risk prostate cancer, FCH PET and FCH PET/WBMRI depict significantly more metastatic lesions than do conventional imaging and WBMRI. Stage determined with PET/WBMRI may correlate with early outcomes.

AJR. American journal of roentgenology. 2018 Jan 11 [Epub ahead of print]

Ur Metser, Alejandro Berlin, Jaydeep Halankar, Grainne Murphy, Kartik S Jhaveri, Sangeet Ghai, Noam Tau

1 Joint Department of Medical Imaging, Princess Margaret Cancer Centre, University Health Network, Mount Sinai Hospital and Women's College Hospital, University of Toronto, 610 University Ave, Toronto, ON M5G 2M9, Canada., 2 Department of Radiation Oncology, University of Toronto and Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada.