Risk of Bone Metastases on [18f]naf PET/CT in 734 Patients with Newly Diagnosed Prostate Cancer

International guidelines recommend assessment for bone metastases in patients with high-risk prostate cancer (PC) and those with unfavourable intermediate-risk disease. These recommendations are largely based on studies using planar bone scintigraphy. We aimed to assess the diagnostic accuracy of [18F]sodium fluoride ([18F]NaF) PET/CT in newly diagnosed PC. We also evaluated the clinical utility of routine bone imaging in patients with unfavourable intermediate-risk disease and International Society of Urological Pathology grade group (ISUP GG) 3. This retrospective single-center study included 734 consecutive patients with newly diagnosed PC who underwent [18F]NaF PET/CT for primary staging. Patients were classified according to the current European Association of Urology risk classification, with the intermediate-risk subgroup restricted to patients with ISUP GG 3. All scan reports were retrospectively reviewed, and patient-level findings regarding bone metastases were validated against a reference standard based on follow-up imaging and clinical data. Sensitivity, specificity, and predictive values were calculated. Of the 734 patients, 607 (83