Objective: Transrectal ultrasound cannot accurately depict early cancer recurrences after prostate high-intensity focused ultrasound (HIFU) ablation. We evaluated transrectal color Doppler (CD) in guiding post-HIFU prostate biopsy.
Methods: Prostate CD-guided sextant biopsies were obtained in 82 patients who had undergone prostate HIFU ablation for cancer, 24 of whom had hormone therapy before the treatment. At the time of biopsy, a subjective CD score was given to all biopsy sites (0=no flow; 1=minimal flow; 2=suspicious flow pattern). CD findings were compared with biopsy results.
Results: CD was a significant predictor of biopsy findings, according to univariate and multivariate site-by-site analysis. However, only 36 of 94 sites with residual cancer had positive CD findings, and thus, negative CD findings should not preclude random biopsy. There was a significant interaction between CD diagnostic capability and a history of hormone therapy before HIFU treatment. CD was a significant and independent predictor of biopsy findings in patients who had not received hormone therapy (odds ratio: 4.4; 95%CI: 2.5-7.9; p<0.0001), but not in those who had (odds ratio: 1.3; 95%CI: 0.5-3.4; p>0.5).
Conclusion: Biopsy taken in CD-positive sites were 4.4 times more likely to contain cancer in patients who did not receive hormone therapy. CD could not reliably depict cancer recurrence in patients with history of hormone therapy.