Detection of Recurrent Prostate Carcinoma withanti-1-Amino-3-18F-Fluorocyclobutane-1-Carboxylic Acid PET/CT and111In–Capromab Pendetide SPECT/CT

Purpose To compare the diagnostic performance of the synthetic amino acid analog radiotracer anti-1-amino-3-fluorine 18-fluorocyclobutane-1-carboxylic acid (anti-3-18F-FACBC) with that of indium 111 (111In)–capromab pendetide in the detection of recurrent prostate carcinoma. Materials and Methods This prospective study was approved by the institutional review board and complied with HIPAA guidelines. Written informed consent was obtained. Fifty patients (mean age, 68.3 years ± 8.1 [standard deviation]; age range, 50–90 years) were included in the study on the basis of the following criteria: (a) Recurrence of prostate carcinoma was suspected after definitive therapy for localized disease, (b) bone scans were negative, and (c) anti-3-18F-FACBC positron emission tomography (PET)/computed tomography (CT) and 111In–capromab pendetide single photon emission computed tomography (SPECT)/CT were performed within 6 weeks of each other. Studies were evaluated by two experienced interpreters for abnormal uptake suspicious for recurrent disease in the prostate bed and extraprostatic locations. The reference standard was a combination of tissue correlation, imaging, laboratory, and clinical data. Diagnostic performance measures were calculated and tests of the statistical significance of differences determined by using the McNemar χ2 test as well as approximate tests based on the difference between two proportions. Results For disease detection in the prostate bed, anti-3-18F-FACBC had a sensitivity of 89% (32 of 36 patients; 95% confidence interval [CI]: 74%, 97%), specificity of 67% (eight of 12 patients; 95% CI: 35%, 90%), and accuracy of 83% (40 of 48 patients; 95% CI: 70%, 93%). 111In–capromab pendetide had a sensitivity of 69% (25 of 36 patients; 95% CI: 52%, 84%), specificity of 58% (seven of 12 patients; 95% CI: 28%, 85%), and accuracy of 67% (32 of 48 patients; 95% CI: 52%, 80%). In the detection of extraprostatic recurrence, anti-3-18F-FACBC had a sensitivity of 100% (10 of 10 patients; 95% CI: 69%, 100%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 100% (17 of 17 patients; 95% CI: 80%, 100%). 111In–capromab pendetide had a sensitivity of 10% (one of 10 patients; 95% CI: 0%, 45%), specificity of 100% (seven of seven patients; 95% CI: 59%, 100%), and accuracy of 47% (eight of 17 patients; 95% CI: 23%, 72%). Conclusion anti-3-18F-FACBC PET/CT was more sensitive than 111In–capromab pendetide SPECT/CT in the detection of recurrent prostate carcinoma and is highly accurate in the differentiation of prostatic from extraprostatic disease. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102023/-/DC1