[Power Doppler Imaging and prostate cancer: optional or necessary technique?]

To evaluate the value of power Doppler sonography (PDS) in patients with a serum PSA level greater than 3.5 ng/ml and note the advantages of PDS in management of biopsy cores and staging in prostate cancer.

A group of 579 patients with a serum PSA level greater than 3.5 ng/ml underwent sextant biopsies. PDS of the prostate was performed in all patients before biopsy indication. Patients underwent six initial sextant biopsies without Doppler. In 141 patients who retained an elevated serum PSA level, an additional series of six to eight ultrasound-guided biopsies with Doppler were indicated. A total of 299 cancers were diagnosed (126 palpable) after initial biopsies and 85 (13 palpable) after additional biopsies. One hundred seven patients with localized cancer (48 palpable) underwent a radical prostatectomy.

An echographic or vascular anomaly was detected in 335 patients; after biopsies this anomaly corresponded to 260 cancers, 39 of which were not visible (false-negative Doppler results). The negative predictive value was 84% and there was no significant relation between PSA level and negative predictive value. After initial biopsies, if an abnormal Doppler signal was present the risk of having positive additional biopsies was 83%. Abnormal disoriented irregular vessels were present in 69% of patients with a Gleason score of 7 or higher versus 31% in patients with a Gleason score less than 7 (p<0.01). Twenty out of 39 patients with T1c cancer invisible with PDS and not palpable (13% of all cancers) underwent a radical prostatectomy. Eleven of 16 cancers with a Gleason score of 6 or less were found insignificant, but in two cases the lesion was advanced (p<0.01). Of cancers with a tumor vessel crossing the capsule, 71% presented an extraprostatic extension (Se: 37.5%, Spe: 93%, PPV: 71%, NPV: 78%) (p<0.01).

In prostatic cancer, PDS allows evaluation of aggressiveness features and can optimize the number of useful biopsy cores.