[The value of diffusion-weighted MR imaging combined with transrectal ultrasound for transrectal prostate biopsy].

Objective: To retrospectively analyze the clinical value of diffusion-weighted MR imaging in the detection of prostate cancer in suspected patients.

Methods: Between January 2009 and December 2010, the 551 patients suspected as prostate cancer underwent prostate biopsy. Patients in group A were accepted to a transrectal ultrasound (TRUS) guided transrectal prostate biopsy (n = 410), while patients in group B were accepted to a diffusion weighted imaging (DWI) and TRUS jointly guided transrectal prostate biopsy (n = 141). The two groups were divided into 4 subgroups by prostate specific antigen (PSA) < 10 µg/L, 10 µg/L ≤ PSA < 20 µg/L, 20 µg/L ≤ PSA < 50 µg/L and PSA ≥ 50 µg/L. Then, the diagnostic rates of prostate biopsy guided by combination of DWI and TRUS with only TRUS were compared.

Results: The diagnostic rate of patients with PSA < 10 µg/L, 10 µg/L ≤ PSA < 20 µg/L, 20 µg/L ≤ PSA < 50 µg/L and PSA ≥ 50 µg/L were 12.1%, 31.1%, 48.0%, 91.2% in group A, and 23.7%, 35.5%, 66.7%, 96.3% in group B, respectively. In the patients with PSA less than 10 µg/L, there were significant differences in diagnostic rate between the two biopsy techniques (χ(2) = 4.405, P < 0.05).

Conclusion: The combination of DWI and TRUS showed the potential to guide biopsy to cancer foci in patients suspected as prostate cancer. For patients with PSA < 10 µg/L, a DWI and TRUS jointly guided transrectal prostate biopsy was recommended.