Tiny Bubbles Blow Up Prostate Imaging

Prostate cancer in an advanced stage detected with ultrasound microbubble technique

(RxWiki News) Detecting prostate cancer is not always simple. A doctor may have to take up to 18 tissue samples to find the disease. A way of imaging with tiny bubbles may make diagnosis easier.

A novel ultrasound technique, using microbubbles to enhance the contrast of the imaging, offers a potentially more accurate way to detect aggressive prostate cancers while reducing the number of biopsies performed.

"Carefully evaluate different approaches for prostate screening."

Ethan Halpern, MD, co-director of the Prostate Diagnostic Center at Thomas Jefferson University Hospital and professor of radiology and urology at Thomas Jefferson University in Philadelphia, led research that confirmed the effectiveness of microbubble imaging approach that has already been successfully used in Europe.

The method was shown to be effective in a 2010 study out of Eindhoven University of Technology and Academic Medical Centre (AMC) in Amsterdam.

According to Dr. Halpern, "Today, a physician may sample 12 to 18 tissue cores from the prostate in order to help diagnose a patient. But with contrast-enhanced, that number drops to six or even less. So it's less invasive, and a more effective guidance tool,” Dr. Halpern said.

Ultrasound works based on a scientific principle that sound reflects off objects, and that information can be translated into images. It is often used to determine the size of the prostate and where to place a needle for biopsy. But it typically does not provide enough detail to distinguish benign tissue from malignant (cancerous) tissue.

Cancerous tumors have a blood vessel structure and flow that differs from healthy organ tissue. When injected into the prostate, microbubbles act as a contrast agent that enhances the reflection of ultrasound waves. The bubbles allow scientists to view tumors and distinguish them from normal organ tissue.

In the Jefferson University study, 118 out of 311 men had positive prostate cancer biopsies. The average age of the patients was 62 years old.

Scientists compared two approaches: Taking targeted biopsies of up to six tissue samples using microbubble scanning versus a conventional biopsy approach taking 12 tissue samples.

Ultrasound with microbubbles found many more high-grade cancers. High-grade cancer is a very deadly, aggressive cancer that can spread quickly.

The new scanning technique found cancers in 55 percent of the men compared to the conventional biopsy approach, which found cancer in 17 percent of the men.

“We've found that with contrast-enhanced ultrasound, we are much more likely to detect cancers on the image, and in this case, the higher grades," said Dr. Halpern.

“Our ultimate goal is to perform a limited number of targeted biopsies and leave the rest of the prostate alone.”

Dr. Halpern added that the new approach should provide a safer, more cost-effective way to diagnose prostate cancer. Total fees for a prostate biopsy range around $2,000.

Investigators remarked that contrast-enhanced ultrasound can also be an effective tool for monitoring low-grade cancers.

At this time, the U.S. Food and Drug Administration hasn't approved the technique for use in prostate screening, although it is used in other imaging applications.

The study was published online in September in the Journal of Urology. The National Cancer Institute supported the four-year trial. No conflicts of interest were reported.

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Review Date: 
October 5, 2012