Der Stellenwert der erweiterten Saturationsbiopsie in der Detektion von Prostatakarzinomen nach unauffälligen Stanzbiopsien

Abstract

Purpose: Patients with at least one negative prostate biopsy but persistent clinical suspicion for carcinoma underwent an extensive saturation prostate biopsy. We evaluated whether an “ideal” number of cores exists, and whether a biopsy protocol relating the number of cores to prostate volume is reasonable. Patients and Methods: Between February 1999 and December 2007, a total of 121 patients underwent biopsy; between 25 and 139 cores were sampled, respectively. All patients received general or spinal anaesthesia. In one step, we divided the patients in three groups according to the number of cores taken (<50, 51-75, >76 cores). In another step, they were split up into five groups depending on the number of cores taken per milliliter of prostate volume(<0,7, 0,8-1,2, 1,3-1,7, 1,8-2,2, >2,2 cores per ml prostate volume). Carcinoma detection rate was compared in both groups. Results: Prostate carcinoma was detected in 48 patients (39,7%). In the three groups depending on the number of cores, carcinoma detection increased insignificantly (32,7% vs 34,5% vs 52,5%; p=0,13). In the five groups according to the number of cores per ml prostate volume the differences in carcinoma detection were significant (8,3% vs 36,6% vs 44,8% vs 71,4% vs 61,5%; p<0,001). Complications were recorded in 4 cases (3,3%). Conclusion: We achieved high carcinoma detection rates with a relatively high number of cores. An “ideal” fixed number of cores is not advisable due to largely differing prostate sizes. However, linking the number of cores to prostate volume takes exactly these differences into account and may prevent undersampling of larger prostates. Although 2 or more cores per ml prostate volume achieved the highest carcinoma detection rates, in everyday practice this is still too much. Therefore we advise to take 1 to 1 ½ cores per ml prostate volume for high detection rates and a still reasonable protocol.