PROSTATE BIOPSY INDEXES - TOWARD EFFICIENT USE OF TRANSRECTAL ULTRASOUND

With increasing use of transrectal ultrasonography (TRUS) it becomes i mportant to establish guidelines for its appropriate utilization. Thre e hundred and twenty-two patients with either an abnormal digital rect al examination (DRE) or prostate-specific antigen (PSA), or both, were evaluated further for cancer by means of prostatic ultrasonography. T wo hundred and twenty-five (70%) of these underwent ultrasound-guided biopsy, cancer was detected in 74 (23%), and 33 percent of all biopsy specimens were positive. Thus, the indices of biopsy: TRUS (Bx:T), can cer: TRUS (Ca:T), and cancer: biopsy (Ca:Bx) were 70 percent, 23 perce nt, and 33 percent, respectively. Comparing these indices with other e arlier series (TRUS used less selectively) and with more recent series (TRUS used more selectively), suggest that ratios in the range of bio psy: TRUS of 70 percent to 75 percent, cancer: TRUS of 25 percent to 3 0 percent, and cancer:biopsy of 30 percent to 40 percent may be expect ed with appropriate use of this imaging modality.