Prostate carcinoma: Transrectal US after cryosurgical ablation

PURPOSE: To characterize the transrectal ultrasound (US) morphology of the prostate after cryosurgical ablation and correlate these findings with the detection of residual tumor at transrectal US-directed biopsy. MATERIALS AND METHODS: Findings from 24 transrectal US examinations in 15 patients (age range, 63-75 years) who had undergone cryosurgical ablation of the prostate were reviewed. Prospective identification of focal lesions with transrectal US and retrospective review of US prostate morphology were correlated with clinical data and transrectal US-directed biopsy results. RESULTS: Identification of a focal lesion with transrectal US yielded a sensitivity of 13%, specificity of 69%, positive value of 17%, and negative predictive value of 61% for the detection of residual carcinoma. US prostate morphology was variable and distorted in the majority of cases. CONCLUSION: Identification of focal lesions with transrectal US is not a reliable criterion for the detection of residual tumor in the prostate after cryosurgical ablation. Systematic biopsy should not be deferred owing to lack of transrectal US identification of focal abnormalities in patients with appropriate clinical indications.