Usefulness of perflubutane microbubble-enhanced ultrasound in imaging and detection of prostate cancer: phase II multicenter clinical trial
To explore the possibility of targeted biopsy (TBx) using transrectal ultrasound (US) with perflubutane microbubbles, we studied the findings of different cancerous tissue imaging modalities and evaluated needle biopsy in prostate cancer (PCa) using contrast-enhanced US (CEUS) in a multicenter clinical trial. Seventy-one patients undergoing prostate biopsy received intravenous injection of perflubutane microbubbles (Sonazoid®). We evaluated and compared images obtained by CEUS. The safety observation period was 2 days after contrast administration. Among the 30 patients with cancer, one or more sites with findings suggestive of cancer in CEUS were detected in 23 patients (32.4%) by TBx. Although 22 patients had positive cores of cancer by systematic biopsy (SBx), 8 patients had positive cores of cancer in TBx alone (11.3%). There was a significant difference in cancer detection rate by TBx between two cohorts with PSA < 10 ng/mL (22.9%) and PSA ≥ 10 ng/mL (52.2%) (P < 0.02). Close observation of various CEUS findings with Sonazoid® enabled targeting of cancerous areas, and consequently, a significant difference (P < 0.05) in the detection rate of cancer was recognized in the transition zone (TZ): SBx; 21/120 (17.5%) and TBx; 17/55 (30.9%). The incidence of adverse events was 6.7% and that of adverse reactions was 4%. CEUS with Sonazoid® improved the detection rate of PCa by visualizing cancerous lesions. More detailed examination of CEUS images provided efficient characterization especially in the TZ area. TBx according to this procedure is expected to enable a lower number of biopsies and more accurate diagnosis of PCa.