Intra-individual comparison of (68)Ga-PSMA-11-PET/CT and multi-parametric MR for imaging of primary

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Intra-individual comparison of (68)Ga-PSMA-11-PET/CT and multi-parametric MR for imaging of primary prostate cancer.

Multi-parametric magnetic resonance imaging (MP-MRI) is currently the most comprehensive work up for non-invasive primary tumor staging of prostate cancer (PCa). Prostate-specific membrane antigen (PSMA)-Positron emission tomography-computed tomography (PET/CT) is presented to be a highly promising new technique for N- and M-staging in recurrent PCa-patients. The actual investigation analyses the potential of (68)Ga-PSMA11-PET/CT to assess the extent of primary prostate cancer by intra-individual comparison to MP-MRI.

In a retrospective study, ten patients with primary PCa underwent MP-MRI and PSMA-PET/CT for initial staging. All tumors were proven histopathological by biopsy. Image analysis was done in a quantitative (SUVmax) and qualitative (blinded read) fashion based on PI-RADS. The PI-RADS schema was then translated into a 3D-matrix and the euclidian distance of this coordinate system was used to quantify the extend of agreement.

Both MP-MRI and PSMA-PET/CT presented a good allocation of the PCa, which was also in concordance to the tumor location validated in eight-segment resolution by biopsy. An Isocontour of 50 % SUVmax in PSMA-PET resulted in visually concordant tumor extension in comparison to MP-MRI (T2w and DWI). For 89.4 % of sections containing a tumor according to MP-MRI, the tumor was also identified in total or near-total agreement (euclidian distance ≤1) by PSMA-PET. Vice versa for 96.8 % of the sections identified as tumor bearing by PSMA-PET the tumor was also found in total or near-total agreement by MP-MRI.

PSMA-PET/CT and MP-MRI correlated well with regard to tumor allocation in patients with a high pre-test probability for large tumors. Further research will be needed to evaluate its value in challenging situation such as prostatitis or after repeated negative biopsies.

European journal of nuclear medicine and molecular imaging. 2016 Mar 14 [Epub ahead of print]

F L Giesel, F Sterzing, H P Schlemmer, T Holland-Letz, W Mier, M Rius, A Afshar-Oromieh, K Kopka, J Debus, U Haberkorn, C Kratochwil

Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany. ., Department of RadioOncology, University Hospital Heidelberg, Heidelberg, Germany., Department of Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany., Department of Biostatistics, German Cancer Research Center (DKFZ), Heidelberg, Germany., Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany., Institute of Transuranium Elements, European Commission (EC), Karlsruhe, Germany., Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany., Division of Radiopharmaceutical Chemistry, German Cancer Research Center (DKFZ), Heidelberg, Germany., Department of RadioOncology, University Hospital Heidelberg, Heidelberg, Germany., Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany., Department of Nuclear Medicine, University Hospital Heidelberg, INF 400, 69120, Heidelberg, Germany.

PubMed http://www.ncbi.nlm.nih.gov/pubmed/26971788