Random Systematic Versus Directed Ultrasound Guided Transrectal Core Biopsies of the Prostate

Abstract

Random systematic ultrasound guided transrectal core biopsies of the prostate were compared to directed biopsies of specific hypoechoic defects in 136 men with abnormal prostates on digital rectal examination. Prostate cancer was diagnosed in 83 of 136 patients (62 per cent). In 80 of 83 individuals (94 per cent) the cancer was detected by random systematic biopsies alone. Of 57 men in whom random systematic and directed biopsies were obtained the results of biopsy agreed in 86 per cent, while in 9 per cent random systematic biopsies found cancers missed by directed biopsies and in 5 per cent directed biopsies diagnosed cancers missed by random systematic prostate biopsies. Ultrasound guided random systematic biopsy is simple and easily learned. When combined with additional directed biopsies of the rare hypoechoic areas not included in the pattern of systematic sampling, it provides a highly accurate means to diagnose prostate cancer, minimizing observer and sampling errors. This technique of prostate mapping with 6, 1.5 cm. cores provides valuable additional information on cancer volume, Gleason grade and the potential location of surgically positive margins, all without compromising the operation or the chance for a surgical cure.