Diagnostic Accuracy of<sup>18</sup>F-PSMA-1007 PET/CT Imaging for Lymph Node Staging of Prostate Carcinoma in Primary and Biochemical Recurrence
Katharina Sprute, Vasko Kramer, Stefan A. Koerber, Manuel Meneses, René Fernández, Cristian Soza‐Ried, M. Eiber, Wolfgang Weber, Isabel Rauscher, Kambiz Rahbar, Michael Schaefers, Tadashi Watabe, Motohide Uemura, Sadahiro Naka, Norio Nonomura, Jun Hatazawa, Constantin Schwab, Viktoria Schütz, Markus Hohenfellner, Tim Holland‐Letz, Jürgen Debus, Clemens Kratochwil, Horacio Amaral, P L Choyke, Uwe Haberkorn, Camilo Sandoval, Frederik L. Giesel
Abstract
Prostate-specific membrane antigen (PSMA)–ligand PET/CT is performed on patients with prostate cancer to stage the disease initially or to identify sites of recurrence after definitive therapy. On the basis of clinical results, <sup>18</sup>F-PSMA-1007 is a promising PSMA PET tracer, but detailed histologic confirmation has been lacking. <b>Methods:</b> Ninety-six patients with prostate cancer underwent <sup>18</sup>F-PSMA-1007 PET/CT followed by either radical prostatectomy with lymphadenectomy or salvage lymphadenectomy. The histologic findings of PSMA PET–positive nodes were analyzed retrospectively. A lesion-based and patient-based analysis was performed comparing all positive lesions and only lesions larger than 3 mm on histopathology. <b>Results:</b> Of the patients, 90.6% received <sup>18</sup>F-PSMA-1007 PET/CT for staging before the primary treatment, whereas 9.4% underwent imaging for biochemical recurrence. In 34.4% of the cohort, positive lymph nodes were present on imaging. In total, 1,746 lymph nodes were dissected in 96 patients. <sup>18</sup>F-PSMA-1007 PET had a lesion-based sensitivity of 81.7%, a specificity of 99.6%, a positive predictive value of 92.4%, and a negative predictive value of 98.9% for detecting positive lymph nodes larger than 3 mm. In the analysis of all malignant nodes regardless of size, the overall sensitivity, specificity, positive predictive value, and negative predictive value on lesion-based analysis were 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 larger than 3 mm. <b>Conclusion:</b><sup>18</sup>F-PSMA-1007 PET/CT reliably detects malignant lymph nodes and has an exceptional specificity of more than 99% for nodal metastases.