68Ga ligands targeting prostate-specific membrane antigen (PSMA) are rapidly emerging as a significant step forward in the management of prostate cancer. PSMA is a type II transmembrane protein with high expression in prostate carcinoma cells. We prospectively evaluated the use of 68Ga-PSMA positron emission tomography/computed tomography (PET/CT) in patients with prostate cancer and compared the results to those for technetium-99m (99mTc)-10-metacyloyloxydecyl dihydrogen phosphate (MDP) bone scintigraphy (BS).
A total 113 patients with biopsy-proven prostate cancer referred for standard-of-care BS were prospectively enrolled onto this study. 68Ga-PSMA PET/CT was performed after BS. Metastasis diagnosed on each technique was compared against a final diagnosis based on CT, magnetic resonance imaging, skeletal survey, clinical follow-up, and histologic correlation.
Ninety-one bone lesions were interpreted as bone metastases in 25 men undergoing 68Ga-PSMA PET/CT compared to only 61 lesions in 19 men undergoing 99mTc-MDP BS. Of the 7 bone scans that missed skeletal metastases, 54% of these missed lesions were due to either marrow or lytic skeletal metastases. The median standardized uptake value in all malignant bone lesions was 13.84. 68Ga-PSMA PET/CT showed significantly higher sensitivity and accuracy than BS (96.2% vs. 73.1%, and 99.1% vs. 84.1%) for the detection of skeletal lesions. For extraskeletal lesions, 68Ga-PSMA PET/CT showed an additional 96 unexpected lesions with a median standardized uptake value of 17.6.
68Ga-PSMA PET/CT is superior to and can potentially replace bone scan in the evaluation for skeletal metastases in the clinical and trial setting because of its ability to detect lytic and bone marrow metastases.
Clinical genitourinary cancer. 2018 Jul 21 [Epub ahead of print]
Thabo Lengana, Ismaheel O Lawal, Tebatso G Boshomane, Gbenga O Popoola, Kgomotso M G Mokoala, Evelyn Moshokoa, Alex Maes, Neo P Mokgoro, Christophe Van de Wiele, Mariza Vorster, Mike M Sathekge
Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa., Department of Epidemiology and Community Health, University of Ilorin, Ilorin, Nigeria., Department of Urology, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa., Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa; Department of Nuclear Medicine, AZ Groeninge, Kortrijk, Belgium., Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa; Department of Radiology and Nuclear Medicine, University Ghent, Ghent, Belgium., Department of Nuclear Medicine, University of Pretoria & Steve Biko Academic Hospital, Pretoria, South Africa. Electronic address: .