Multiparametric MRI and 18F-PSMA-1007 PET/CT for the Detection of Clinically Significant Prostate Cancer.

Background Multiparametric MRI (mpMRI) is effective for detecting prostate cancer (PCa); however, there is a high rate of equivocal Prostate Imaging Reporting and Data System (PI-RADS) 3 lesions and false-positive findings. Purpose To investigate whether fluorine 18 (18F) prostate-specific membrane antigen (PSMA) 1007 PET/CT after mpMRI can help detect localized clinically significant PCa (csPCa), particularly for equivocal PI-RADS 3 lesions. Materials and Methods This prospective study included participants with elevated prostate-specific antigen (PSA) levels referred for prostate mpMRI between September 2020 and February 2022. 18F-PSMA-1007 PET/CT was performed within 30 days of mpMRI and before biopsy. PI-RADS category and level of suspicion (LOS) were assessed. PI-RADS 3 or higher lesions at mpMRI and/or LOS 3 or higher lesions at 18F-PSMA-1007 PET/CT underwent targeted biopsies. PI-RADS 2 or lower and LOS 2 or lower lesions were considered nonsuspicious and were monitored during a 1-year follow-up by means of PSA testing. Diagnostic accuracy was assessed, with histologic examination serving as the reference standard. International Society of Urological Pathology (ISUP) grade 2 or higher was considered csPCa. Results Seventy-five participants (median age, 67 years [range, 52-77 years]) were assessed, with PI-RADS 1 or 2, PI-RADS 3, and PI-RADS 4 or 5 groups each including 25 participants. A total of 102 lesions were identified, of which 80 were PI-RADS 3 or higher and/or LOS 3 or higher and therefore underwent targeted biopsy. The per-participant sensitivity for the detection of csPCa was 95% and 91% for mpMRI and 18F-PSMA-1007 PET/CT, respectively, with respective specificities of 45% and 62%. 18F-PSMA-1007 PET/CT was used to correctly differentiate 17 of 26 PI-RADS 3 lesions (65%), with a negative and positive predictive value of 93% and 27%, respectively, for ruling out or detecting csPCa. One additional significant and one insignificant PCa lesion (PI-RADS 1 or 2) were found at 18F-PSMA-1007 PET/CT that otherwise would have remained undetected. Two participants had ISUP 2 tumors without PSMA uptake that were missed at PET/CT. Conclusion 18F-PSMA-1007 PET/CT showed good sensitivity and moderate specificity for the detection of csPCa and ruled this out in 93% of participants with PI-RADS 3 lesions. Clinical trial registration no. NCT04487847 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Radiology. 2024 May [Epub]

Bastiaan M Privé, Bas Israël, Marcel J R Janssen, Marloes M G van der Leest, Maarten de Rooij, Jolique A van Ipenburg, Marianne Jonker, Steffie M B Peters, Michel de Groot, Patrik Zámecnik, Alexander Hoepping, Joyce G Bomers, Martin Gotthardt, J P Michiel Sedelaar, Jelle O Barentsz, Inge M van Oort, James Nagarajah

From the Department of Medical Imaging and Nuclear Medicine (B.M.P., B.I., M.J.R.J., M.M.G.v.d.L., M.d.R., S.M.B.P., M.d.G., P.Z., J.G.B., M.G., J.O.B., J.N.), Department of Urology (B.I., J.P.M.S., I.M.v.O.), and Department of Radiation Oncology (B.I.), Radboud University Medical Center, Radboud Institute for Health Sciences, PO Box 9101, 6500 HB Nijmegen, the Netherlands; Department of Radiation Oncology, Erasmus Medical Center, Cancer Institute, Rotterdam, the Netherlands (B.M.P.); Department of Pathology (J.A.v.I.) and Department of Health Evidence, Biostatistics Section (M.J.), Radboud University Medical Center, Nijmegen, the Netherlands; and Department of Medicinal Chemistry, ABX Advanced Biochemical Compounds, Radeberg, Germany (A.H.).