Stockholm, Sweden—An inexpensive, noninvasive imaging modality is proving successful for verifying the presence of prostate cancer.
Preliminary results on 24 men, presented at the 2014 European Association of Urology Congress, showed that the method—called contrast-ultrasound dispersion imaging (CUDI)—has a 77.9% sensitivity and a 82.4% specificity. The technique could significantly reduce the need for invasive, painful, and costly biopsies if confirmed in larger studies.
CUDI involves giving a boost to normal ultrasound with a 2.4-mL injection of contrast medium containing microbubbles (SonoVue; Bracco, Milan); these highlight the significant concentration of blood vessels around tumors. The only extra costs, besides that for standard ultrasonography, are approximately $60 (US dollars) for the microbubble solution, plus the cost of the software to decipher the resulting images once it is on the market.
Based on this successful pilot trial at 3 hospitals, the researchers have patented the technique and are expanding their research network.
“More and more hospitals are asking to join our studies. Therefore, in 2015, I expect at least 5 Dutch hospitals will be involved. We should be able to take targeted biopsies by CUDI in large trials in 2016,” said lead investigator Massimo Mischi, PhD, MSc, Head, Biomedical Diagnostics Research Lab, Eindhoven University of Technology, the Netherlands. “The US is somewhat behind Europe in contrast enhanced ultrasound imaging due to FDA restrictions,” he said. Dr Mischi noted that this is about to change, thanks to the involvement of the International Contrast Ultrasound Society “in promoting research on contrast-enhanced ultrasound and disseminating the results.”
The pilot trial included 19 patients from the Academic Medical Center University Hospital, Amsterdam, the Netherlands, and 5 patients from Jeroen Bosch Hospital, ‘s-Hertogenbosch, the Netherlands. The investigators analyzed the estimated intravascular dispersion of the ultrasound contrast agent, which reflects the angiogenic changes to the microvascular architecture caused by cancer growth. The researchers then compared the results to the histologic results gathered after the patients’ prostates were removed by radical prostatectomy.
The investigators focused on two 0.5-cm2 regions in each prostate—one with benign tissue and the other with cancerous tissue—to determine CUDI’s accuracy. The results revealed that the contrast agent’s dispersion pattern had a high sensitivity and specificity for determining the location and size of the tumors.
Other CUDI parameters analyzed, such as the area under the time-intensity curve formed as the ultrasound probe passed across the surface of the prostate, were not as sensitive or specific for tumor tissue.
