Preoperative staging of pelvic lymph nodes in prostate cancer by 11C-choline PET

Prostate cancer is known for its difficulties in preoperative staging of pelvic lymph nodes by conventional imaging techniques. Thus, a histopathologic examination of the pelvic lymphadenectomy specimen is mandatory for patients at risk for metastatic disease. The aim of this study was to evaluate the strength and accuracy of C-11-choline PET in preoperative noninvasive staging of pelvic lymph nodes in prostate cancer. Methods: In a prospective study we examined 67 consecutive patients with histologically proven prostate cancer with C-11-choline PET. The results of PET were compared with the results of histology of the pelvic lymph nodes and with the follow-up data. Conventional axial imaging was routinely performed using MRI or CT. The sensitivity, specificity, and accuracy of C-11-choline PET were calculated. Results: Fifteen patients had histologically proven lymph node metastases. C-11-Choline PET was true-positive in 12 of 15 patients and false-negative in 3 patients. Fifty-two patients had no lymph node metastases. C-11-Choline PET was true-negative in 50 of 52 patients and false-positive in 2 patients. We calculated a sensitivity of C-11-choline PET for staging metastatic lymph node disease of 80%, a specificity of 96%, and an accuracy of 93%. Next, C-11-choline PET detected solitary extraregional lymph node metastases in 5 of 12 patients with nodal metastases. Conclusion: This study showed that C-11-choline PET is sensitive and accurate in preoperative staging of pelvic lymph nodes in prostate cancer.