[(18)F]-fluorocholine positron-emission/computed tomography for lymph node staging of patients with prostate cancer: preliminary results of a prospective study

Study Type - Diagnostic (case series) Level of Evidence 4 OBJECTIVES To evaluate prospectively [(18)F]-fluorocholine positron-emission/computed tomography (FCH PET/CT) for lymph node staging of prostate cancer before intended curative therapy, and to determine whether imaging 15 or 60 min after radiotracer injection is preferable. PATIENTS AND METHODS In all, 25 consecutive patients with newly diagnosed prostate cancer (Gleason score >6, and/or a prostate-specific antigen level of >10 ng/mL, and/or T3 cancer) were scanned before lymphadenectomy. Each patient was assessed twice with imaging, at 15 and 60 min after the injection with FCH. Images were compared with the results of histopathological examination of the surgically removed lymph nodes. Maximum standardized uptake values (SUV(max)) at 15 and 60 min were also compared. RESULTS Histopathologically, metastases were present in removed lymph nodes from three patients. FCH PET/CT showed a high radiotracer uptake in four patients, the former three and a fourth. The sensitivity, specificity, positive and negative predictive value of FCH PET/CT for patient based lymph node staging of prostate cancer were 100%, 95%, 75% and 100%, respectively; the corresponding 95% confidence intervals were 29.2-100%, 77.2-99.9%, 19.4-99.4% and 83.9-100%, respectively. Values of SUV(max) at early and late imaging were not significantly different. CONCLUSIONS This small series supports the use of FCH PET/CT as a tool for lymph node staging of patients with prostate cancer. Values of SUV(max) at early and late imaging did not differ. However, larger prospective studies are needed to validate these findings.