Lesion localization in patients with a previous negative transrectal ultrasound biopsy and persistently elevated prostate specific antigen level using diffusion-weighted imaging at three Tesla before rebiopsy.

OBJECTIVE

To assess the use of diffusion-weighted imaging (DWI) at 3 Tesla (T) for lesion localization in patients with a high risk of prostate cancer before a rebiopsy.

MATERIALS AND METHODS

A total of 43 patients (age range, 40-80 years; mean age, 62.6 years) who had previously undergone a transrectal ultrasound (TRUS)-guided biopsy that was negative and continued to have a persistent elevated prostate specific antigen level underwent DWI with b = 0 s/mm and b = 1000 s/mm before a rebiopsy. We located the area of the lowest apparent diffusion coefficient values and performed a target biopsy of that area, followed by a systematic biopsy under TRUS guidance. We evaluated the cancer detection rate, tumor location, and lesion visibility on T2-weighted imaging (T2WI) in patients with biopsy-proven cancers.

RESULTS

Prostate cancer was detected in 17 (39.5%) patients, and was more predominant in the transitional zone (76.4%, 13/17) than in the peripheral zone (23.6%, 4/17) (P < 0.05). Of the 17 cancers detected on DWI, 6 lesions were seen on T2WI.

CONCLUSION

DWI in addition to T2WI at 3 T has the potential to provide important information on lesion localization in patients that had both previous negative TRUS biopsy and persistently elevated prostate specific antigen levels before a repeated biopsy.