Initial experience with 18F-PSMA-11 PET/CT in recurrent prostate cancer evaluation

Early and precise diagnostics of recurrent prostate cancer (PCa) are a cornerstone for further adequate therapy planning. The aim of this study was to compare the diagnostic tools - 18F-PSMA-1007 positron emission tomography (PET/CT), magnetic resonance imaging (MRI) and bone scintigraphy for evaluation of local recurrence, regional lymph nodes and distal bone metastases. In this prospective study 29 PCa patients with biochemical relapse were enrolled, who previously received radical prostatectomy and/or radiation therapy. All included patients underwent PET/CT, MRI and bone scintigraphy. Clinical data of patients and/or follow-up information were used as the reference standard. The evaluation of local recurrence and regional lymph node metastases was based on results of PET/CT and MRI. Local recurrent disease in 29 patients was detected by PET/CT in 35 % (n=10/29) and by MRI in 31% (n=9/29) with sensitivity, specificity, accuracy 90.9%, 100%, 96.5% and 81.8%, 100%, 93.1%, respectively. Nodal involvement was evaluated by PET/CT and MRI in 48% (n=14/29) and 28% (n=8/29). Against the standard of reference, sensitivity, specificity and accuracy for PET/CT were 92.9%, 93.3%, 93.1% and for MRI - 57.1%, 100%, 79.3%, respectively. The evaluation of skeletal metastases is based on PET/CT and bone scintigraphy. Bone metastases by PET/CT and bone scintigraphy were seen in 21 % (6/29) and 19% (5/26) with sensitivity, specificity and accuracy 100%; 92.0%; 93.1% and 50.0%; 86.0%; 80.8%, respectively. Our comparative study results revealed 18F-PSMA-1007 PET/CT as superior diagnostic tool to other methods for evaluation of recurrence. However, as study results show that MRI and scintigraphy also have relatively high accuracy and due to methods availability, multimodal imaging still has its role in recurrent prostate cancer diagnostics.