Comparison of 11C-choline with 18F-FDG in positron emission tomography/computerized tomography for staging urothelial carcinoma: a prospective study.

Abstract

11C-choline was postulated to provide better diagnostic capabilities than other tracers used in positron emission tomography/computerized tomography for staging urothelial carcinoma. We compared the value of using 11C-choline with the well investigated 18F-FDG tracer in this setting. The study group included 20 consecutive patients with bladder cancer who underwent evaluation for local and metastatic disease using 11C-choline and 18F-FDG positron emission tomography/computerized tomography. Patients were treated with radical cystectomy with lymph node dissection, radiation therapy or chemotherapy independent of positron emission tomography/computerized tomography results. The histopathological findings (when available), followup positron emission tomography and radiological imaging served as the reference standard. Using the paired t test we compared the maximum standardized uptake and lesion-to-background ratio of the tracers. The positive predictive values were determined. A total of 51 lesions showed abnormal tracer activity. The positive predictive value for all detected lesions was 84.7% for 11C-choline positron emission tomography/computerized tomography and 90.7% for 18F-FDG positron emission tomography/computerized tomography. The corresponding positive predictive values for extravesical lesions were 79.4% and 88.2%, respectively. Discrepant findings between the tracers were noted at 11 sites. 18F-FDG positron emission tomography/computerized tomography correctly identified 4 extravesical metastases missed by choline positron emission tomography/computerized tomography in the absence of a contrary observation. Mean maximum standardized uptake and lesion-to-background ratio at extravesical sites were significantly higher for FDG. Within the limitations of a relatively small number of patients and partial histopathological analysis, 11C-choline positron emission tomography/computerized tomography appears to have no advantage compared to 18F-FDG positron emission tomography/computerized tomography in the detection of metastatic bladder cancer. 18F-FDG positron emission tomography/computerized tomography has a tendency toward greater accuracy.