The accuracy of CT in the staging of carcinoma of the prostate

Previous studies have reported the accuracy of CT in distinguishing stages of prostatic carcinoma, but they lack uniform surgical proof of histopathologic stage. We evaluated CT scans in 32 patients who underwent radical prostatectomy to assess its role in the preoperative staging of prostatic carcinoma. Two experienced radiologists blindly interpreted CT scans of the pelvis; they looked for evidence of tumor beyond the prostatic capsule and involvement of the seminal vesicles (stage C) or involvement of pelvic lymph nodes (stage D). Sixty-four interpretations in 32 patients yielded a specificity of 75% for predicting stages A or B disease (local disease), a sensitivity of 50% for the prediction of stages C or D, and an overall accuracy of staging of 67%. Interpretation errors were due to an inability to detect lymph node metastases, errors in evaluating the seminal vesicles, and errors in interpreting densities surrounding the prostate gland. Our data suggest that CT should not be used to influence decisions concerning surgical vs nonsurgical treatment in patients with clinically staged local disease and is only useful when unsuspected metastatic nodal disease is detected.