Diagnostic accuracy of 18F-PSMA-1007-PET/CT imaging for lymph node staging of prostate carcinoma in primary and biochemical recurrence.

Purpose: Prostate specific membrane antigen (PSMA) -ligand PET/CT is performed in patients with prostate cancer to stage the disease initially or to identify sites of recurrence after definitive therapy. 18F-PSMA-1007 is a promising PSMA-PET tracer based on clinical results, but detailed histologic confirmation has been lacking. Experimental Design: 96 patients with prostate cancer received a 18F-PSMA-1007-PET/CT followed by either radical prostatectomy with lymphadenectomy or salvage lymphadenectomy. The histological findings of PSMA-PET-positive nodes were analysed retrospectively. A lesion and a patient-based analysis was performed comparing 1) all positive and 2) only lesions with a size larger than 3 mm in histopathology. Results: 90.6% of the patients received 18F-PSMA-1007-PET/CT for staging before the primary treatment, while 9.4 % of the cohort underwent imaging for biochemical recurrence. In 34.4% of the cohort positive lymph nodes were present in imaging. A total of 1746 lymph nodes were dissected in 96 patients. 18F-PSMA-1007-PET had a lesion-based sensitivity of 81.7% a specificity of 99.6%, a positive predictive value (PPV) of 92.4%, a negative predictive value (NPV) of 98.9% for detecting positive lymph nodes larger than 3 mm. In the analysis of all malignant nodes regardless the size the overall sensitivity, specificity, PPV, and NPV on lesion-based analysis was 71.2%, 99.5%, 91.3%, and 97.9%, respectively. The patient-based analysis showed a sensitivity of 85.9% and a specificity of 99.5% for lymph nodes >3 mm. Conclusion:18F-PSMA-1007-PET/CT reliably detects malignant lymph nodes and has an exceptional specificity of >99% for nodal metastases.

Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2020 Aug 17 [Epub ahead of print]

Katharina Sprute, Vasko Kramer, Stefan Koerber, Manuel Meneses, Rene Fernandez, Cristian Soza-Ried, Mathias Eiber, Wolfgang Weber, Isabel Rauscher, Kambiz Rahbar, Martin Schaefers, Tadashi Watabe, Motohide Uemura, Sadahiro Naka, Norio Nonomura, Jun Hatazawa, Constantin Schwab, Viktoria Schütz, Markus Hohenfellner, Tim Holland-Letz, Juergen Debus, Clemens Kratochwil, Horacio Amaral, Peter L Choyke, Uwe Haberkorn, Camilo Sandoval, Frederik L Giesel

University Hospital Heidelberg, Germany., Positronpharma SA, Chile., Fundación Arturo Lopez Perez, FALP., Center of Nuclear Medicine PositronMed., Technical University of Munich, Germany., University Hospital Muenster, Germany., Osaka University Graduate School of Medicine, Japan., Osaka University Hospital., Department of Pathology, Heidelberg University Hospital, Heidelberg, Germany., German Cancer Research Center (DKFZ)., Molecular Imaging Program, Center for Cancer Research, National Cancer Institute (NCI)/ National Institutes of Health (NIH), United States.