High-Tech Prostate Scan May Boost Cancer Detection
Combo of ultrasound and MRI zeroes in on tumors, helping some men avoid biopsy, experts say
By Dennis Thompson
FRIDAY, Aug. 16 (HealthDay News) -- An innovative fusion of MRI and ultrasound might be a better way to detect and assess prostate cancer, while helping men avoid unnecessary biopsies, researchers say.
The technology blends real-time imaging from both MRI and ultrasound devices, allowing doctors to more accurately direct the biopsy needle that draws cell samples from suspected tumors.
"This approach does detect cancers that can go missed by standard biopsy," said Dr. Art Rastinehad, assistant professor of urology and radiology and director of Interventional Urologic Oncology at Hofstra University-North Shore LIJ School of Medicine in Hempstead, N.Y.
In particular, the MRI/ultrasound fusion technique can guide physicians to tumors at normally neglected regions of the prostate gland.
"There are two screens in front of you, and the MRI is capable of pointing out areas that might contain cancer," explained Dr. Scott Eggener, associate professor of surgery and director of translational and outcomes research in the University of Chicago Medical Center's urology section. "Using the two screens, you can more intelligently direct your biopsy needles toward those areas."
The technology is part of an overall approach to first use MRI scans to best determine which men need to undergo prostate biopsy, and then use the MRI/ultrasound fusion to perform the most efficient biopsy possible.
Right now, doctors typically rely on blood tests to look for elevated levels of prostate-specific antigen, or PSA. A man with an elevated PSA is often urged to undergo a biopsy, most often conducted using a needle guided by ultrasound that draws cell samples from the prostate.
However, these biopsies only sample a small portion of the prostate, leaving the rest of the gland unchecked. Such random sampling can easily miss tumors, experts say.
Under the new approach, a man with elevated PSA levels would first undergo an MRI that would provide a visual scan of the entire prostate, Rastinehad explained. If potentially cancerous areas are found on the prostate, then the man would undergo a biopsy.
Studies have found that using an initial MRI scan to figure out who needs a biopsy can reduce the overall number of biopsies by about a third, according to a review of the data published this summer in the journal European Urology.
"We are working toward a goal that if you have a PSA that is elevated, you would instead get an MRI," Rastinehad said. For some patients, that may mean that "you may never need a biopsy," he said.
MRI also would be used during the biopsy itself. In that scenario, an electro-magnetic field generator is placed over the patient's hip, creating real-time MRI images that are combined with ultrasound readings to guide the needle biopsy. Images from the earlier MRI screening can then be overlaid with the real-time images to provide visible "targets" for the doctor to biopsy.