SERUM PSA ADJUSTED FOR VOLUME OF TRANSITION ZONE (PSAT) IS MORE ACCURATE THAN PSA ADJUSTED FOR TOTAL GLAND VOLUME (PSAD) IN DETECTING ADENOCARCINOMA OF THE PROSTATE

Objective. This study evaluates the accuracy of comparing serum prosta te-specific antigen (PSA) levels in the range between 4.1 ng/mL and 10 .0 ng/mL (monoclonal) to the volume of the transition zone (TZ) of the prostate and total gland volume as a predictor of a positive biopsy. Methods. Using sonographic voluming of the entire prostate and of the TZ, prostate-specific antigen density (PSAD) and prostate-specific ant igen density of the TZ (PSAT) were calculated in 21 biopsy-positive pa tients and 38 biopsy-negative patients. Biopsy was directed at sonogra phically suspicious areas and did not include sextant biopsies. Result s. A statistically significant association was determined between a po sitive biopsy and gland volume, TZ volume, and PSAT. The association o f a positive biopsy with PSA and PSAD was not statistically significan t. Conclusions. PSAT is more accurate in predicting a positive biopsy than is PSAD for PSA levels between 4.1 ng/mL and 10.0 ng/mL.