Current standard imaging techniques are insufficient to reliably detect lymph node (LN) metastases in prostate cancer (PCa). Recently, ligands of the prostate-specific membrane antigen (PSMA) have been introduced in PET imaging of PCa.
Thus, the aim of this retrospective analysis was to investigate the diagnostic efficacy of (68)Ga-PSMA-PET imaging for LN staging of patients with PCa scheduled for radical prostatectomy (RPX) and to compare it with morphological imaging (CT, MR) with histopathological evaluation as standard of reference.
From 12/2012 to 11/2014, 130 patients with intermediate to high-risk PCa were staged with (68)Ga-PSMA-PET/MR or PET/CT before RPX and template pelvic LN dissection. Histopathological findings of resected tissue were statistically correlated with the results of (68)Ga-PSMA-PET and morphological imaging in a patient- and template-based manner.
LN metastases were found in 41/130 (31. 5%) patients. On patient-based analysis sensitivity, specificity and accuracy for (68)Ga-PSMA-PET were calculated as 65. 9%, 98. 9% and 88. 5% and 43. 9%, 85. 4% and 72. 3% for morphological imaging, respectively. 117/734 (15. 9%) of dissected LN templates showed metastases. On template-based analysis sensitivity, specificity and accuracy for (68)Ga-PSMA-PET were 68. 3%, 99. 1% and 95. 2% while for morphological imaging 27. 3%, 97. 1% and 87. 6% were calculated. On ROC-analysis (68)Ga-PSMA-PET performed significantly superior to morphological imaging alone on a patient- (p=0. 002) and template-based analysis (p<0. 001).
In patients with intermediate to high-risk PCa preoperative LN staging with (68)Ga-PSMA-PET proved to be superior to standard routine imaging and thus has the potential to replace current standard imaging for this indication if confirmed by prospective studies.
The Journal of urology. 2015 Dec 09 [Epub ahead of print]
Tobias Maurer, Jürgen E Gschwend, Isabel Rauscher, Michael Souvatzoglou, Bernhard Haller, Gregor Weirich, Hans-Jürgen Wester, Matthias Heck, Hubert Kübler, Ambros J Beer, Markus Schwaiger, Matthias Eiber
Department of Urology. Department of Urology. , Department of Nuclear Medicine. , Department of Nuclear Medicine. , Institute of Medical Statistics and Epidemiology. , Institute of Pathology. , Department of Pharmaceutical Radiochemistry Technische Universität München, Klinikum rechts der Isar, Munich, Germany. , Department of Urology. , Department of Urology. , Department of Nuclear Medicine; Department of Nuclear Medicine, University of Ulm. , Department of Nuclear Medicine. , Department of Nuclear Medicine.