Directed biopsy during contrast-enhanced sonography of the prostate.

OBJECTIVE: We evaluated the value of directed biopsy for the detection of prostate cancer during contrast-enhanced endorectal sonography. SUBJECTS AND METHODS: Forty patients were evaluated with harmonic gray-scale sonography. The evaluation was performed before administration of contrast agent, during continuous IV infusion of perflutren lipid microspheres, and again during bolus administration of the microspheres. Sextant biopsy sites were scored prospectively on a six-point scale for suggestion of malignancy at baseline during contrast infusion and after bolus administration. An additional directed core was obtained at 20 of the sextant biopsy sites based on contrast-enhanced imaging.
RESULTS: Cancer was identified in 30 biopsy sites in 16 of the patients (40%). A suspicious site identified during contrast-enhanced transrectal sonography was 3.5 times more likely to have positive biopsy findings at than an adjacent site that was not suggestive of malignancy (p < 0.025). When a suspicious site was evaluated with an additional biopsy core, the site was five times more likely to have a biopsy with positive findings than a standard sextant site (p < 0.01). We found no difference in diagnostic accuracy between continuous infusion of contrast material and bolus administration.
CONCLUSION: Contrast-enhanced transrectal sonography improves the sonographic detection of malignant foci in the prostate. The performance of multiple biopsies of suspicious enhancing foci significantly improves the detection of cancer. There is no advantage to additional examination of the gland after bolus administration of contrast material.