(Ultrasound Review) Transrectal color Doppler reflects the state of angiogenesis in prostate cancer, according to urologists at Shimane Medical University in Izumo, Japan. Previous research has found that the degree of angiogenesis is a clinically important indicator of tumor stage, degree of dissemination and even prognosis.
The investigators studied 56 patients that had radical prostatectomy and color Doppler ultrasound. They compared computer-assisted quantification of color pixel intensity with microvessel density in the postoperative prostate specimens. Also, prostatectomy specimens were assessed for vascular endothelial growth factor (VEGF) immunoreactivity. Their results were recently published in the British Journal of Urology.
Prostate volume and morphology were assessed with transrectal ultrasound using a 5 MHz transducer. Relevant ultrasound images were stored as 24-bit RGB TIFF files at 200 dpi. Pixel intensity was calculated by counting the number of color pixels above a specific intensity within a 20mm2 box centered over the region of highest vascularity on color Doppler.
Results indicated a significant correlation between color pixel intensity and microvessel density, and they discovered an increase in color pixel intensity with raised levels of VEGF immunoreactivity. No significant correlation was found when the pixel intensity was compare with the patients’ Gleason score.
The authors discussed the use of MR imaging for prostate assessment, but suggested this modality was costly and took much longer compared with sonographic assessment with color Doppler.
"In summary, blood flow assessed by color Doppler ultrasound may reflect the state of angiogenesis in prostate cancer, which is implicated in tumor progression and/or patient survival," the authors stated.
They suggested future applications for this technique might include using color Doppler for monitoring the effect of treatments such as antiangiogenic therapy. The authors described ultrasound imaging as quick, relatively inexpensive and more easily repeated than transrectal biopsy.
Transrectal colour Doppler ultrasonography for quantifying angiogenesis in prostate cancerShigeno, K. et al.
Department of urology, Shimane Medical University, Izumo, Japan
British Journal of Urology 2003 Feb; 91: 223-226
By Ultrasound Review
June 6, 2003
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