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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.