Prostate-specific membrane antigen (PSMA)-PET/CT has shown considerable promise in the evaluation of prostate cancer bone metastases; however, data utilizing a histopathologic reference standard in this setting are limited. We therefore sought to evaluate the diagnostic performance of PSMA-PET/CT using a consistent histopathologic gold standard in the form of bone biopsy.
In this single-center, retrospective study, we identified 80 patients with prostate cancer who underwent CT-guided bone biopsy of a tracer-avid osseous lesion on PSMA-PET/CT performed with 18F-piflufolastat. Concordance between PET/CT and histopathology and the positive predictive value of PSMA-PET/CT were determined. Factors predictive of positive biopsies were also evaluated.
PSMA-PET/CT and bone biopsy results were concordant in 55/80 patients (69%), and the positive predictive value of PSMA-PET/CT for osseous metastasis of prostate cancer was 66% (53/80). Positive predictive values for spine, pelvis, and rib biopsies were 82% (23/28), 72% (18/25), and 26% (5/19), respectively. Peak SUV and its ratio to liver mean SUV were significantly higher in biopsy-positive lesions compared to biopsy-negative lesions. A threshold peak SUV to liver mean SUV ratio of 1.7 had a sensitivity of 61% and a specificity of 92% for a histopathologic diagnosis of metastatic prostate cancer.
PSMA-PET/CT has a moderately high histopathologic concordance and positive predictive value for the diagnosis of osseous metastatic disease in prostate cancer. Peak SUV is useful for distinguishing biopsy-positive from biopsy-negative lesions. In keeping with prior investigations, a majority of biopsied rib lesions were negative for metastatic prostate cancer.
Skeletal radiology. 2024 Dec 20 [Epub ahead of print]
William C Ou, Jack W Jennings, Benjamin E Northrup, Gino M Dettorre, Winston L Winkler, Resten Imaoka, Theodore L Vander Velde, Barry A Siegel
Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Campus, Box 8131, St. Louis, MO, 63110, USA. ., Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Campus, Box 8131, St. Louis, MO, 63110, USA.