Integrated 68Gallium Labelled Prostate-Specific Membrane Antigen-11 Positron Emission Tomography/Magnetic Resonance Imaging Enhances Discriminatory Power of Multi-Parametric Prostate Magnetic Resonance Imaging

To evaluate diagnostic accuracy of integrated 68Gallium labelled prostate-specific membrane antigen (68Ga-PSMA)-11 positron emission tomography (PET)/MRI in patients with primary prostate cancer (PCa) as compared to multi-parametric MRI.

A total of 22 patients with recently diagnosed primary PCa underwent clinically indicated 68Ga-PSMA-11 PET/CT for initial staging followed by integrated 68Ga-PSMA-11 PET/MRI. Images of multi-parametric magnetic resonance imaging (mpMRI), PET and PET/MRI were evaluated separately by applying Prostate Imaging Reporting and Data System (PIRADSv2) for mpMRI and a 5-point Likert scale for PET and PET/MRI. Results were compared with pathology reports of biopsy or resection. Statistical analyses including receiver operating characteristics analysis were performed to compare the diagnostic performance of mpMRI, PET and PET/MRI.

PET and integrated PET/MRI demonstrated a higher diagnostic accuracy than mpMRI (area under the curve: mpMRI: 0.679, PET and PET/MRI: 0.951). The proportion of equivocal results (PIRADS 3 and Likert 3) was considerably higher in mpMRI than in PET and PET/MRI. In a notable proportion of equivocal PIRADS results, PET led to a correct shift towards higher suspicion of malignancy and enabled correct lesion classification.

Integrated 68Ga-PSMA-11 PET/MRI demonstrates higher diagnostic accuracy than mpMRI and is particularly valuable in tumours with equivocal results from PIRADS classification.

Urologia internationalis. 2018 Jan 25 [Epub ahead of print]

Mohammad Al-Bayati, Johannes Grueneisen, Susanne Lütje, Lino M Sawicki, Saravanabavaan Suntharalingam, Stephan Tschirdewahn, Michael Forsting, Herbert Rübben, Ken Herrmann, Lale Umutlu, Axel Wetter

Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen, Germany., Department of Nuclear Medicine, University Hospital Essen, Essen, Germany., Department of Urology, University Hospital Essen, Essen, Germany., Department of Urology, Helios Marien Klinik Duisburg, Duisburg, Germany., Department of Diagnostic and Interventional Radiology, University of Dusseldorf, Medical Faculty, Dusseldorf, Germany.