"Real-world" evaluation of 18F-Choline PET/CT practices in prostate cancer patients and impact on changes in therapeutic strategy

Abstract

Objectives: The role of ¹⁸F-fluorocholine positron emission tomography/computed tomography (¹⁸F-Choline PET/CT) in different clinical situations remains controversial and current practices are very heterogeneous. The aim of this study was to evaluate the "real-world" practice of ¹⁸F-Choline PET/CT in patients with prostate cancer and its potential impacts on therapeutic strategy.

Methods and materials: This is a retrospective multicenter observational study including 265 consecutive men who underwent ¹⁸F-Choline PET/CT for prostate cancer between November 2014 and November 2015. Primary outcome was impact on therapeutic strategy. Secondary outcomes were sensitivity of the ¹⁸F-Choline PET/CT and predictive factors associated with positive scans. Statistical analyses comprised Student's t test for continuous variables or chi-squared test for qualitative variables.

Results: Median PSA level at the time of PET/CT was 4.19 ng/ml. The decision to perform PET/CT was made after multidisciplinary discussion in 29.8% of cases; most were prescribed by urologists (50.2% of cases). Three main indications were concerned: biochemical recurrence after local treatment (61.1%), initial staging (26.0%), or at the time of progression to castration-resistance (12.9%). Upon biochemical recurrence, ¹⁸F-Choline PET/CT allowed identification of ≥1 site(s) with a sensitivity of 80.9%. In multivariate analysis, predictive factors associated with ¹⁸F-Choline PET/CT sensitivity were serum PSA level and local treatment type in cases of biochemical recurrence, and PSA doubling time and Gleason score in case of initial staging. ¹⁸F-Choline PET/CT results allowed restaging and change in therapeutic strategy in 58.1% of all combined indications.

Conclusions: Indications of ¹⁸F-Choline PET/CT were varied. The detection rate of metastatic lesions was suitable, especially when PSA rate was >1 ng/mL. In most cases, ¹⁸F-Choline PET/CT led to a change in therapeutic strategy, particularly in the setting of biochemical recurrence.

Keywords: (18)F-Choline PET/CT; Biochemical recurrence; Castration-resistance; Prostate cancer; Staging.