Transrectal ultrasound in the diagnosis and staging of prostatic carcinoma.

Indications for TRUS are: (a) for diagnosis of nonpalpable cancer, or detection of cancer with greater accuracy than is possible at present; (b) for guidance of transrectal biopsies of hypoechoic lesions for histologic confirmation of cancer; (c) for guidance of staging biopsies to ensure diagnoses of extraprostatic extension; and (d) for staging previously diagnosed prostate cancer.