11C-Choline positron emission tomography/computerized tomography for tumor localization of primary prostate cancer in comparison with 12-core biopsy

Purpose: C-11-choline positron emission tomography is an innovative imaging technique for prostate cancer. We assessed the sensitivity of positron emission tomography used together with computerized tomography for intraprostatic localization of primary prostate cancer on a nodule-by-nodule basis, and compared its performance with 12-core transrectal biopsy. Materials and Methods: In 43 patients with known prostate cancer who had received positron emission tomography/ computerized tomography before initial biopsy, we assessed sensitivity of positron emission tomography/computerized tomography for localization of nodules 5 mm or greater (those theoretically large enough for visualization) using radical prostatectomy histopathology as the reference standard. Comparison with transrectal ultrasound guided biopsy was based on sextant assessment of all cancer foci following sextant-by-sextant matching and reconstruction. Sensitivity/specificity of positron emission tomography/computerized tomography and magnetic resonance imaging for prediction of extraprostatic extension was also assessed. Results: Positron emission tomography/computerized tomography showed 83% sensitivity for localization of nodules 5 mm or greater. At logistic regression analysis only nodule size appeared to influence sensitivity. At sextant assessment positron emission tomography/computerized tomography had slightly better sensitivity than transrectal ultrasound guided biopsy (66% vs 61%, p = 0.434) but was less specific (84% vs 97%, p = 0.008). For assessment of extraprostatic extension, sensitivity of PET/CT was low in comparison with magnetic resonance imaging (22% vs 63%, p < 0.001). Conclusions: Positron emission tomography/computerized tomography has good sensitivity for intraprostatic localization of primary prostate cancer nodules 5 mm or greater. Positron emission tomography/computerized tomography and transrectal ultrasound guided biopsy show similar sensitivity for localization of any cancer focus. Positron emission tomography/ computerized tomography does not seem to have any role in extraprostatic extension detection. Studies of diagnostic accuracy (as opposed to tumor localization) are needed in patients with suspected prostate cancer to see whether positron emission tomography/computerized tomography could have a role in not selected patients.