Correlation between Doppler Vascular Density and PSA Response to Radiation Therapy in Patients with Localized Prostate Carcinoma

The authors performed this study to ascertain whether there is a correlation between pretreatment Doppler vascular density (DVD) of the prostate and prostate-specific antigen (PSA) response following radiation therapy in prostate cancer patients. Prior to radiation therapy, 14 patients with biopsy-proven carcinoma (of Gleason grades 2–7) were imaged with transrectal ultrasound in gray-scale, color Doppler, and power Doppler modes. The Doppler images were analyzed for mean DVD with the aid of a computer program. PSA levels were measured before therapy and every 3 months after therapy. The PSA measurements were fitted to an exponential to determine PSA halving time ( T 1/2). Correlations were made between T 1/2> and the following pretherapy measurements: mean DVD, PSA level, prostate volume, and Gleason grade. Median follow-up time was 392 days. A linear correlation with regression coefficient ( R) of 0.75–0.80 was observed between mean DVD and T 1/2> for color Doppler and power Doppler imaging. In both imaging modes, each percentage increase in mean DVD led to an increase in T 1/2> by 25 days. Pretherapy prostate volume, PSA level, and Gleason score did not correlate with T 1/2>. The pretreatment mean DVD correlates inversely with the rate of posttherapy decline in PSA in patients with prostate cancer. That is, pretreatment vascularity prognosticates postirradiation PSA response. The mechanism underlying this correlative relationship is not known.