April 8, 2014
New Prostate Cancer Test May Remove The Need For Painful Biopsies
April Flowers for redOrbit.com - Your Universe Online
Globally, over one million men a year have prostate tissue samples taken to check for signs of prostate cancer. This procedure can involve up to 12 large biopsy needles and has been called barbaric by Mayo Graduate School of Medicine Professor Matthew Gettman. As well, it reveals that 70 percent of the men undergoing the procedure do not have cancer. Beyond being unnecessarily painful and risky for the patient, the procedure is prohibitively costly—approximately $2,500 USD.
Every year, prostate cancer kills hundreds of thousands of men worldwide. At the beginning of any prostate cancer exam, clinicians will measure the Prostate Specific Antigen (PSA) value in the blood. If the PSA is high, samples of prostate tissue will be collected through the anus at six to sixteen points for pathological testing. Despite high PSA values, 70 percent of those biopsied show no signs of cancer.
This doesn't mean a high PSA level is a false alarm, however. It is possible the biopsy was taken at the wrong site.
Among those with negative results, 30 percent are later found to have cancer. Among those patients who have cancerous results from the biopsy, the exact size of the tumor remains unknown. For many of these, subsequent surgery shows that the tumors were so small that surgery was not required. The biopsy procedure leads to inflammations in up to five percent of the patients.
Massimo Mischi, TU/e Associate Professor of Engineering, led the research team. They have developed a new technique for determining whether and where men have prostate cancer using existing ultrasound scanners. Ultrasound scanners use sound waves to create images of the body's internal organs, but they are usually unable to show the differences between healthy and tumor tissue. Tumor tissues produces a large number of small blood vessels with a characteristic pattern in order to grow, and Mischi's team used this pattern to make the tumor visible.
A single injection of contrast medium that contains tiny bubbles can be seen by the ultrasound scanner, right down to the smallest blood vessels. The computer uses advanced image-analysis techniques that can recognize the characteristic blood vessel pattern to generate an image showing the location of the tumor. The exam takes a total of one minute, and results are available moments later—without costly biopsy analysis.
The team compared the results of their "tumor images" with the actual prostates removed by surgery from 24 patients from three hospitals in the Netherlands. The comparison confirmed that the locations and sizes of the tumors were well indicated by the images.
TU/e has patented the new technique, which can help prevent the need for biopsies for millions of men around the world. For a large portion of the 70 percent of men who currently have biopsies performed unnecessarily, the images will eliminate the need all together. For the 30 percent who are cancerous, the need for biopsies will be lessened because the location and size of the tumor will already be clear. The researchers hope that the need for the painful and costly biopsies will be eliminated all together once sufficient clinical practice has proven the imaging method.
Next year, AMC Amsterdam and the two other participating Dutch hospitals will conduct a major comparative study between the old and new methods. Both methods will be used on at least 250 men, and if all goes well, the new technique will be made available in 2016 to more patients. The introduction of the new method will be quite simple, as most hospitals already have the ultrasound equipment necessary.