[Prostate biopsy -- practical examination of the adequacy of Chen's virtual strategy]

Prostate sextant biopsy is considered the gold standard of invasive prostate cancer diagnostics. However, numerous studies have shown that greater detection rates are achieved by increasing the number of biopsies. Chen et al. found ten "ideal" biopsy sites using a computer model. This study examines the clinical value of this variation of number and localisation of biopsies.

Ultrasound-guided ten-core prostate biopsies are performed in our department. Following the model of Chen, three prostate biopsies instead of on are taken from the middle plane. The two additional specimens are obtained in the paraurethral and ventral regions.

Between July 2003 and February 2004, 191 patients scheduled for a 10-core prostate biopsy were included in the study. Assessable results were obtained in 176 cases. A carcinoma was detected in 61/176 (34.7 %) of the patients. The carcinoma was found only in the standard sextant localisations (27.8 %) in 17/61 patients and additionally in the paraurethral or ventral region in 35/61 (57.3 %). The carcinoma was located only paraurethrally in 1/62 (1.6 %) and only ventrally in 6/62 (9.7 %). Altogether, the prostate carcinoma was detected only by the additional biopsies in 6 patients (9.8 %). A clinically relevant disease was seen in 5/6 (83.3 %). A carcinoma was detected most frequently in the following biopsies: base right (17.1 %), central lat. right (17.5 %) and apex right (16.5 %) and most rarely paraurethral right (12 %) and ventral right (10.2 %). Statistically significant differences were found only between these groups.

The modification and increase of biopsies from six to ten according to the model suggested by Chen et al. detected 9.8 % more carcinomas in our patients.