18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is accurate for high-grade prostate cancer bone staging when compared to bone scintigraphy

Abstract

Introduction: In this study, we compared 18F-FDG-postron emission tomography/computed tomography (PET/CT) and bone scintigraphy accuracies for the detection of bone metastases for primary staging in high-grade prostate cancer (PCa) patients to determine if 18F-FDG-PET/CT could be used alone as a staging modality. Methods: Men with localized high-grade PCa (n=256, Gleason 8–10, International Society of Urological Pathology [ISUP] grades 4 or 5) were imaged with bone scintigraphy and 18F-FDG-PET/CT. We compared on a per-patient basis the accuracy of the two imaging modalities, taking intermodality agreement as the standard of truth (SOT). Results: 18F-FDG-PET/CT detected at least one bone metastasis in 33 patients compared to only 26 with bone scan. Of the seven false-negative bone scintigraphies, four (57.1%) were solitary metastases (monometastatic), three (42.9%) were oligometastatic (2–4 lesions), and none were plurimetastatic (>4 lesions). Compared to SOT, 18F-FDG-PET/CT showed higher sensitivity and accuracy than bone scintigraphy (100% vs. 78.8%, and 98.7% vs. 98.2%) for the detection of skeletal lesions. Conclusions: 18F-FDG-PET/CT appears similar or better than conventional bone scans to assess for bone metastases in patients newly diagnosed with high-grade PCa. Since intraprostatic FDG-uptake is also a biomarker of failure to radical prostatectomy and that FDG-PET/CT has been shown to be accurate in detecting PCa lymph node metastasis, FDG-PET/CT has the potential to be used as the sole preoperative staging modality in high-grade PCa.