Resumen de Role of 18F-Choline PET/CT in the Initial Staging of High Risk Prostate Cancer and Comparison with Conventional Imaging Techniques

Raquel Sopeña Sutil, A. Gómez Grande, A. González Díaz, Julio Téigell Tobar, Ángeles Cabeza Rodríguez, Enrique González Billalabeitia, Alfredo Rodríguez Antolín

• Objective: To assess the diagnostic accuracy of 18F-Choline PET/CT in the initial staging of high-risk prostate cancer (PC), and to compare it with conventional imaging techniques and to assess the changes in therapeutic attitude derived from its results.

  Secondary Objectives: To assess the concordance between 18F-Choline PET/CT and conventional study and to find related prognostic factors.

  Material and Methods: Retrospective observational study of 78 patients with high-risk PC undergoing 18F-Choline PET/CT after conventional initial staging (CT + BS). Sensitivity, specificity and predictive values of 18F-Choline PET/CT and CT + BS were calculated. The golden standard was histological result or follow-up. Tumor characteristics were collected and univariate and multivariate analyzes were performed.

  Results: The median age was 67 years old and mean PSA was 42.39 ng/mL. The sensitivity, specificity and NPV in global initial staging for PET/CT 18F-Choline and conventional imaging were: 92.9% vs 38.5%, 83.3% vs 42.3%, and 90.9% vs 40.7%, respectively. Lymph node staging: sensitivity 96.3% vs 61.5% and specificity 80% vs 76%, respectively. Bone staging: sensitivity 91.7% vs 21.4% and specificity 97.4% vs 83.8%, respectively. There was agreement in 25 patients (32%) (p = 0.004), Kappa index 0.134 (p = 0.011). The treatment was modified in 47.4% patients. PSA, PSADT% positive cores and cT were related to PET results. PSA level <8.9 ng/mL was considered an independent protective factor for positive PET (OR 0.03) (95% CI: 0.002-0.435, p 0.010).

  Conclusions: 18F-Choline PET/CT seems to be superior to CT + BS for initial staging in high-risk PC. It could be considered because its results can change the treatment decision in almost half of the patients.