PET/MRI combination better than either alone at diagnosing high-risk prostate cancer

Researchers in Norway have shown the superiority of combined fluciclovine F-18 PET with multiparametric MRI over either modality alone for detecting and characterizing high-risk prostate cancers, according to a study published Oct. 6 in the Journal of Nuclear Medicine.

Mattijs Elschot, PhD, of the Norwegian University of Science and Technology and colleagues recruited 28 patients diagnosed with high-risk prostate cancer to receive simultaneous fluciclovine PET and T2-weighted/diffusion-weighted MRI before undergoing radical prostatectomy surgery.

Retrospectively analyzing the imaging data with histology findings as a reference, the team delineated volumes of interest from prostate tumors, benign prostatic hyperplasia (BPH) nodules, prostatitis and healthy tissue on the T2-weighted images.

They then compared the PET, MRI and combined PET/MRI features using the area under the receiver operating characteristic curve.

Their key finding was that the combination features, as compared with PET and MRI features alone, showed “excellent discriminative performance” in helping clinicians separate malignant tissue from benign.

Elschot and colleagues also found the combined approach is clinically feasible on an integrated PET/MRI system and does not increase the total scan time for the patient.

Further, while the additional costs associated with fluciclovine PET “may hinder its use for routine diagnostic imaging in the overall prostate cancer population,” its high diagnostic potential “could be fully exploited in selected cases, such as for diagnosis of patients at high risk for lymph node metastases and for planning of targeted prostate biopsies in highly suspected patients with previous negative biopsies.”

The radiotracer fluciclovine F-18 is marketed under the trade name Axumin by Blue Earth Diagnostics.

The independent study was funded by the Norwegian Cancer Society.