The role of [18F]PSMA-1007 PET/CT in staging of prostate cancer: Influence of bone uptake and relationship with D'Amico risk classification.

Abstract

Background: Prostate cancer represents a significant global health challenge, particularly in Mexico where it ranks as the leading cause of cancer-related mortality among men. The introduction of Prostate-Specific Membrane Antigen labeled with fluoride [¹⁸F]F-PSMA-1007 PET/CT has revolutionized diagnostics, enabling identification of metastases not visible on conventional imaging, although it presents unspecific bone uptake (UBU) in up to 72% of patients.

Methods: Eighty-one patients with newly diagnosed prostate cancer who underwent [¹⁸F]F-PSMA-1007 PET/CT for staging were retrospectively analyzed. Patients were categorized according to D'Amico risk classification. The prevalence of PSMA-positive lesions in various anatomical sites was assessed, defining unspecific bone uptake as focal uptake without meeting PROMISE criteria for osseous metastases.

Results: Metastatic disease, specifically defined by the presence of miN1 and/or miM1a-c lesions, was detected in a substantial majority of the patients, totaling 61 individuals, which corresponds to 75% of the entire cohort. Abnormal bone uptake was identified in 58% of cases, distributed equally across D'Amico risk groups. No significant association was found between bone uptake frequency and antigen prostatic specific (PSA) levels or Gleason score (p = 0.24). However, SUVmax was independently associated with metastasis (adjusted OR 1.67 per 5 units increase, 95% CI 1.31-2.14; p < 0.001). Definite bone metastases were confirmed in 44% of patients with bone uptake using an SUVmax ≥ 10 threshold.

Conclusions: [¹⁸F]F-PSMA-1007 PET/CT significantly enhances primary staging accuracy in prostate cancer, refining the D'Amico risk classification. The SUVmax ≥ 10 threshold allows differentiation between true bone metastases and unspecific bone uptake. Initial PSA levels significantly predict nodal metastases presence, optimizing treatment strategies and patient outcomes.