平沢 潔, 木村 明, 新妻 雅治, 阿曽 佳郎

Kiyoshi HIRASAWA, Akira KIMURA, Masaharu NIIZUMA, Yoshio ASO

東京大学医学部泌尿器科学教室

Department of Urology, Faculty of Medicine, The University of Tokyo

キーワード : Prostatic needle biopsy, Transrectal ultrasound guidance, Biplane transducer

Ultrasonographically, prostatic cancer nodules usually appear hypoechoic. Biopsy techniques to obtain tissue precisely from the hypoecoic lesions suspected of cancer are needed to achieve accurate and prompt diagnosis of prostatic diseases. The study presents the results of transrectal biplane ultrasound guided biopsies of the prostate performed transperineally or transrectally in 54 cases with suspected prostatic cancer by digital rectal examination, transrectal ultrasound, and elevated prostatic serum tumor marker. Transrectal ultrasound images were obtaind with PROSCAN (TEKNAR 7.5 MHz mechanical sector scanning). The transducer can provide both transverse and longitudinal images by switching system, which are demonstrated simultaneously on full speed CRT monitor. One of two images can be shown in real time if necessary. Biopsies were performed from the lithotomy position under sacral anesthesia with an 18-gauge biopsy neeble driven by a spring-loaded gun (Biopty-Gun). In all the cases, satisfactory amount of tissue for histological evaluation was obtained. Pathological examination revealed 10 cases with adenocarcinoma and 44 cases with benign prostatic tissue. Of the 25 cases with hypoechoic lesions in the prostate by ultrasound, 10 proved to be cancer. Transperineal biopsy was more appropriate for obtaining tissue from the whole prostate except for the posterior portion close to the rectum. On the other hand, transrectal biopsy was recommended for biopsy of the posterior portion of the prostate. No significant complication was experienced. This system has the advantage that transverse and londitudinal images can be obtained alternately without changing the probe, and thus prostatic needle biopsy can be performed precisely and safely in combination with the Biopty gun.