Predicting PSA response of prostate cancer to radiation therapy with Doppler sonography

We report a prospective investigation of the correlation between pretreatment Doppler vascular density (DVD) of the entire prostate gland and subsequent prostate-specific antigen (PSA) response following external beam radiation therapy, for patients with low- or intermediate-risk prostate cancer. This report updates a previous report (Sehgal et al., Acad Radiol 2003;10:366) with longer patient follow-up and additional quantitative and clinically relevant end points.

Before radiation therapy, we imaged 12 patients with transrectal Doppler sonography and measured the mean DVD of the prostate for each. For analysis, patients were separated into 3 groups by low, intermediate, and high DVD. The mean DVD for each group was linearly correlated with mean values for time above a PSA threshold of 1.0 ng/ml, post-therapy plateau PSA, and nadir PSA.

We previously observed that pretreatment mean DVD had a strong inverse correlation with initial rate of post-therapy decline in PSA. With substantially longer follow-up on the same cohort of patients (median, 52 months), we now observe that pretreatment mean DVD also correlates with post-therapy nadir PSA (R = 0.94) and with time above a PSA threshold of 1.0 ng/mL (R = 0.99).

The results of the current study are consistent with our earlier suggestion that pretreatment measurement of DVD of the entire prostate gland may be a clinically useful prognostic indicator in early prostate cancer treated with radiation. However, additional data from larger numbers of patients are needed to draw firm conclusions.