Comparison between conventional imaging (abdominal-pelvic computed tomography and bone scan) and [18F]choline positron emission tomography/computed tomography imaging for the initial staging of patients with intermediate- tohigh-risk prostate cancer: A retrospective analysis

Objective. The aim of this study was to evaluate the efficiency of [18F]fluorocholine positron emis- sion tomography/computed tomography (FCH PET/CT) in detecting lymph-node and bone involvement in comparison with conventional imaging, such as abdominal–pelvic CT and bone scan, in the initial staging of prostate cancer (PCa). Materials and methods. The study retro- spectively evaluated 48 patients who had FCH PET/CT for the initial staging of PCa. At the same time, 32 of the 48 patients had a bone scan and 26 of the 48 patients had abdominal–pelvic diag- nostic CT. Diagnostic performance of FCH PET/CT, i.e. sensitivity, specificity and accuracy, was evaluated on a per-patient basis for the whole population and then separately on a per-risk clas- sification, and later in comparison with conventional imaging. Histological specimens or follow- up data were used as the standard of reference. Results. The overall accuracy of FCH PET/CT for lymph-node involvement was 83.3%. The sensitivity of FCH was higher in the high-risk subset (83.3%) than in the intermediate-risk group (33.3%), whereas FCH specificity was similar. In com- parison with dedicated CT scan, FCH PET/CT showed a higher sensitivity and a similar specificity (46.2% vs 69.2% and 92.3% vs 92.3%, respectively). Moreover, the sensitivity and specificity of PET/CT were higher than those of bone scan (100% vs 90% and 86.4% vs 77.2%, respectively). In contrast with conventional imaging, PET/CT changed the staging of the PCa in 33.3% patients. Conclusions. The efficiency of FCH PET/CT in detecting both bone and lymph-node involvement of PCa at initial staging was found to be higher than that of conventional imaging. Prospective clinical trials are needed to confirm these findings.