68Ga-PSMA-PET/CT in comparison with 18F-fluoride-PET/CT and whole-body MRI for the detection of bone metastases in patients with prostate cancer: a prospective diagnostic accuracy study

• Published in: European radiology 2019-03, Vol.29 (3), p.1221-1230
• Main Authors: Dyrberg, Eva, Hendel, Helle W., Huynh, Tri Hien Viet, Klausen, Tobias Wirenfeldt, Løgager, Vibeke B., Madsen, Claus, Pedersen, Erik M., Pedersen, Maria, Thomsen, Henrik S.
• Format: Article
• Language: English
• Subjects: Accuracy; Bone cancer; Bone imaging; Cancer; Coefficients; Computed tomography; Diagnosis; Diagnostic Radiology; Diagnostic systems; Fluorides; Fluorine isotopes; Imaging; Internal Medicine; Interventional Radiology; Magnetic resonance imaging; Mathematical analysis; Medical diagnosis; Medicine; Medicine & Public Health; Metastases; Metastasis; Neuroradiology; NMR; Nuclear magnetic resonance; Oncology; Patients; Population studies; Positron emission; Positron emission tomography; Prostate cancer; Radiology; Tomography; Ultrasound
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-018-5682-x

Objectives To determine the diagnostic accuracy of 68 gallium prostate-specific membrane antigen (PSMA)-based positron emission tomography/computed tomography (PET/CT) in comparison with 18 F-fluoride-based PET/CT (NaF-PET/CT) and whole-body magnetic resonance imaging (WB-MRI) for the detection of bone metastases in patients with prostate cancer. Methods Sixty patients with prostate cancer were included in the period May 2016 to June 2017. The participants underwent three scans (index tests) within 30 days: a NaF-PET/CT, a WB-MRI and a PSMA-PET/CT. Experienced specialists assessed the scans. In the absence of a histological reference standard, the final diagnosis was determined as a panel diagnosis. Measures of the diagnostic performances of the index tests were calculated from patient-based dichotomous outcomes (0 or ≥ 1 bone metastasis) and pairwise compared (McNemar test). For each index test, the agreement with the final diagnosis with regard to the number of bone metastases detected (0, 1–5, > 5) and the inter-reader agreement was calculated (kappa coefficients). Results Fifty-five patients constituted the final study population; 20 patients (36%) were classified as having bone metastatic disease as their final diagnosis. The patient-based diagnostic performances were (sensitivity, specificity, overall accuracy) PSMA-PET/CT (100%, 100%, 100%), NaF-PET/CT (95%, 97%, 96%) and WB-MRI (80%, 83%, 82%). The overall accuracy of PSMA-PET/CT was significantly more favourable compared to WB-MRI ( p = 0.004), but not to NaF-PET/CT ( p = 0.48). PSMA-PET/CT classified the number of bone metastases reliably compared to the final diagnosis (kappa coefficient 0.97) and with an “almost perfect” inter-reader agreement (kappa coefficient 0.93). Conclusions The overall accuracy of PSMA-PET/CT was significantly more advantageous compared to WB-MRI, but not to NaF-PET/CT. Key Points • PSMA-PET/CT assessed the presence of bone metastases correctly in all 55 patients • PSMA-PET/CT was more advantageous compared to WB-MRI • No difference was found between PSMA-PET/CT and NaF-PET/CT