Diagnostic scope of 18F-PSMA-1007 PET/CT: comparison with multiparametric MRI and bone scintigraphy for the assessment of early prostate cancer recurrence.

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 the evaluation of local recurrence, regional lymph nodes and bone metastases of recurrent prostate cancer (PCa). 28 PCa patients after radical prostatectomy and/or radiation therapy and with biochemical relapse were enrolled in this study. The evaluation of local recurrence and regional lymph node metastases was based on results of PET/CT and MRI. Local recurrent disease in 28 patients was detected by PET/CT in 36% (10/28) and by MRI in 32% (9/28) with sensitivity, specificity, accuracy of 90.9%, 100%, 96.4% and 81.8%, 100%, 92.9%, respectively (kappa 0.92, P<0.001). Nodal involvement was confirmed by PET/CT and MRI in 46% (13/28) and 25% (7/28) with sensitivity, specificity and accuracy for PET/CT 92.3%, 93.3%, 92.9% and for MRI-53.8%, 100%, 78.6%, respectively (kappa 0.57, P<0.001). The evaluation of skeletal metastases was based on PET/CT and bone scintigraphy. Bone metastases were seen on PET/CT and bone scintigraphy in 21% (6/28) and 20% (5/25) with sensitivity, specificity and accuracy of 100%; 91.7%; 92.9% and 50.0%; 85.7%; 80.0%, respectively (kappa 0.41, P<0.01). In conclusion, our comparative study demonstrates advantages of ¹⁸F-PSMA-1007 PET/CT compared to MRI and scintigraphy for the evaluation of recurrent prostate cancer. Both methods, ¹⁸F-PSMA-1007 PET/CT and MRI, detect local recurrence with high accuracy and excellent agreement, which may be attributed to the low urinary background clearance of ¹⁸F-PSMA-1007.