Contrast-enhanced ultrasonography using cadence-contrast pulse sequencing technology for targeted biopsy of the prostate

Abstract

Objective: To evaluate contrast-enhanced ultrasonography (US) using cadence-contrast pulse sequencing (CPS) technology, compared with systematic biopsy for detecting prostate cancer, as grey-scale US has low sensitivity and specificity for detecting prostate cancer.

Patients and methods: In all, 44 men with suspicious prostate-specific antigen (PSA) levels and CPS findings were assessed; all had CPS-targeted and systematic biopsy. Transrectal CPS images were taken with a low mechanical index (0.14). A microbubble contrast agent (SonoVue, Bracco International BV, Amsterdam, the Netherlands) was administered as a bolus, with a maximum dose of 4.8 mL. CPS was used to assess prostatic vascularity. Areas with a rapid and increased contrast enhancement within the peripheral zone were defined as suspicious for prostate cancer. Up to five CPS targeted biopsies were taken and subsequently a 10-core systematic biopsy was taken. Cancer detection rates for the two techniques were compared.

Results: Overall, cancer was detected in 35 of 44 patients (80%), with a mean PSA level of 3.8 ng/mL. Lesions suspicious on CPS showed cancer in 35 of 44 patients (80%) and systematic biopsy detected cancer in 15 of 44 patients (34%). CPS-targeted cores were positive in 105 of 220 cores (47.7%) and in 41 of 440 systematic biopsy cores (9.3%) (P < 0.001). Lesions suspicious on CPS were false-positive in nine of 44 patients (20%). The mean Gleason score for systematic biopsy was 6.7 and for CPS-targeted biopsy 6.8 (P > 0.05). The sensitivity of CPS for detecting cancer was 100% (confidence interval, 95%). However, limitations in the series included that only CPS-positive cases were investigated, and CPS-targeted biopsy should be evaluated in a more extended biopsy scheme.

Conclusions: Contrast-enhanced US using CPS enables excellent visualization of the microvasculature associated with prostate cancer, and can improve the detection of prostate cancer compared with systematic biopsy.