18F Choline PET/CT in the Preoperative Staging of Prostate Cancer in Patients with Intermediate or High Risk of Extracapsular Disease: A Prospective Study of 130 Patients

Purpose: To prospectively evaluate the potential value of fluorocholine (FCH) positron emission tomography (PET)/computed tomography (CT) in the preoperative staging of patients with prostate cancer who had intermediate or high risk of extracapsular disease. Materials and Methods: Institutional review board approval and written informed consent were obtained. Overall, 132 patients with prostate cancer (mean age, 63 years 6 7 [standard deviation]) were enrolled between October 2003 and June 2008. Two patients were subsequently excluded. In 111 patients, radical prostatectomy with extended pelvic lymph node (LN) dissection was performed. Patients were categorized into groups with intermediate (n = 47) or high (n = 83) risk of extracapsular extension on the basis of their Gleason scores and prostate specific antigen levels. Imaging was performed with an integrated PET/CT system after injection of 4.07 MBq FCH per kilogram of body weight with acquisition of dynamic images in the pelvis and whole-body images. Statistical analysis was performed on a per-patient basis. Results: Significant correlation was found between sections with the highest FCH uptake and sextants with maximal tumor infiltration (r = 0.68; P = .0001). Overall, 912 LNs were histopathologically examined. A per-patient analysis revealed the sensitivity, specificity, and positive and negative predictive values of FCH PET/CT in the detection of malignant LNs were 45%, 96%, 82%, and 83%, respectively. For LN metastases greater than or equal to 5 mm in diameter, sensitivity, specificity, and positive and negative predictive values were 66%, 96%, 82%, and 92%, respectively. In 13 patients, 43 bone metastases were detected. Early bone marrow infiltration was detected with only FCH PET in two patients. FCH PET/CT led to a change in therapy in 15% of all patients and 20% of high-risk patients. Conclusion: FCH PET/CT could be useful in the evaluation of patients with prostate cancer who are at high risk for extracapsular disease, and it could be used to preoperatively exclude distant metastases. (C)RSNA, 2010