The optimal systematic prostate biopsy scheme should include 8 rather than6 biopsies: Results of a prospective clinical trial

Purpose: We define the optimal systematic biopsy regimen to detect carcinom a of the prostate. Materials and Methods: A total of 483 consecutive patients referred for an abnormal digital rectal examination and/or prostate specific antigen (PSA) 4.0 ng./ml. or greater underwent transrectal ultrasound and systematic biop sy. Lateral biopsies of the peripheral zone at the base and mid gland were added to the routine sextant biopsy regimen for a total of 10 systematic bi opsies of the peripheral zone. Patients with a prostate greater than 50 cc also underwent systematic sextant transition zone biopsy in the mid lobar p arasagittal plane. Detection rates of the various regions were assessed. Va rious biopsy schemes were then created and cancer detection rates were comp ared using McNemar's test. Results: Of the patients 42% (202 of 483) had cancer on biopsy. Traditional sextant biopsies missed 20%, while a sextant regimen incorporating lateral peripheral zone biopsies of the mid gland and base along with the apex mis sed 11% of the cancers. The combination of sextant and lateral peripheral z one biopsies (10-biopsy scheme) detected 194 cancers(96%). The 8 missed can cers were detected by lesion directed (5) or transition zone (3) biopsies. Eliminating the mid lobar base biopsies from the systematic 10-biopsy perip heral zone regimen resulting in an 8-biopsy peripheral zone regimen decreas ed detection from 96% to 95%. Conclusions: The 6 systematic biopsies of the peripheral zone are inadequat e and a minimum of 8, including the apex, mid lobar mid gland, lateral mid gland and lateral base, should routinely be performed.