Innovative Sonographie beim Prostatakarzinom

Zusammenfassung Zur Früherkennung und Stadieneinteilung des Prostatakarzinoms wird heutzutage fast ausschließlich die sog. systematische Mehrfachbiopsie eingesetzt. Hierbei tritt das bildgebende Verfahren – der transrektale Ultraschall – als Diagnostikum mehr und mehr in den Hintergrund und dient fast ausschließlich zur Führung der Biopsienadel in spezifische anatomische Regionen. Doch selbst bei multiplen systematischen Biopsien wird eine hohe Zahl klinisch signifikanter Karzinome übersehen. Diese Tatsache hat zu einer drastischen Steigerung der Anzahl von Gewebeproben geführt. So finden sich Zentren, in denen 6, 10, 12, ja bis zu 143 Gewebeproben in einer Sitzung entnommen werden. Diese immer invasivere heterogene Vorgehensweise bestätigt den Bedarf an Verbesserung in der Ultraschalldiagnostik. Neue und innovative bildgebende Verfahren in der Prostatasonographie werden vorgestellt mit dem Ziel, die diagnostische Aussagekraft bei Erstdiagnose sowie in der Stadienvorhersage zu verbessern. Eine verbesserte Bildgebung bei Diagnosestellung und in der Stadieneinteilung würde zu einer erheblichen Verbesserung bei den Therapieentscheidungen führen.Dieser Beitrag ist dem kürzlich verstorbenen Pathologen J. E. McNeal gewidmet, der die zonale Anatomie der Prostata erstbeschrieben hat.     

Computerized transrectal ultrasound (C-TRUS) of the prostate: detection of cancer in patients with multiple negative systematic random biopsies

This study was designed to compare the diagnostic yield of computerized transrectal ultrasound (C-TRUS) guided biopsies in the detection of prostate cancer in a group of men with a history of multiple systematic random biopsies with no prior evidence of prostate cancer. The question was asked: Can we detect cancer by C-TRUS that has been overlooked by multiple systematic biopsies? The entrance criteria for this study were prior negative systematic random biopsies regardless of number of biopsy sessions or number of individual biopsy cores. Serial static TRUS images were evaluated by C-TRUS, which assessed signal information independent of visual gray scale. Five C-TRUS algorithms were utilized to evaluate the information of the ultrasound signal. Interpretation of the results were documented and the most suspicious regions marked by C-TRUS were biopsied by guiding the needle to the marked location. Five hundred and forty men were biopsied because of an elevated PSA or abnormal digital rectal exam. 132 had a history of prior negative systematic random biopsies (1–7 sessions, median: 2 and between 6 and 72 individual prostate biopsies, median: 12 cores). Additionally, a diagnostic TUR-P of the prostate with benign result was performed in four patients. The PSA ranged from 3.1–36 ng/ml with a median of 9.01 ng/ml. The prostate volume ranged from 6–203 ml with a median of 42 ml. Of the 132 patients with prior negative systematic random biopsies, cancer was found in 66 (50%) by C-TRUS targeted biopsies. In this group the median number of negative biopsy sessions was two and a median of 12 biopsy cores were performed. From literature we would expect a cancer detection rate in this group with systematic biopsies of approximately 7%. We only found five carcinomas with a Gleason Score (GS) of 5, 25 with GS 6, 22 with GS 7, 8 with GS 8 and even 7 with GS 9. The results of this prospective clinical trail indicates that the additional use of the C-TRUS identifies clinical significant cancerous lesions that could not been visualized or detected by systematic random biopsies in a very high percentage. In addition, the results of the study support the efforts to search for strategies that utilize expertise and refinement of imaging modalities rather than elevating the number of random biopsies (f.e. 141 cores in one session) in the detection of prostate cancer.