A team led by University of California San Diego School of medicine describes the new MRI technique called restriction spectrum imaging-MRI (RSI-MRI). This form of MRI produces considerably better results detecting prostate disease than the current contrast based MRI.
Dr. Rebecca Rakow-Penner, a research resident at the UCSD School of Medicines’s Department of Radiology says: “This new approach is a more reliable imaging technique for localizing tumors. It provides a better target for biopsies, especially for smaller tumors.”
Author David S Karow, a UCSD assistant professor of radiology explained how RSI-MRI is valuable in surgical planning and image staging. This method of MRI offers a non-invasive way to more accurately than ever assess the extent of disease and the size of a tumor and even predict its grade. This can help doctors to choose an appropriate form of treatment.
The New MRI technique registers water diffusion in tissue as opposed to blood flow
A contrast-enhanced MRI which is the current standard for detecting and diagnosing prostate disease uses a substance injected into the patient that allows the MRI scanner to register blood flow. This technique provides the ability to spot a tumor type and shape due to differences in the blood flow between healthy and diseased tissue. Diseased tissue typically requires more blood. The drawback is that not all tumors differ enough from healthy tissue to terms of blood demand so some issues of prostate disease can be missed on a contrast-enhanced MRI.
Researchers have been looking to move to a Diffusion MRI to register diffusion of water in tissue as opposed to blood. Diffusion MRI is the gold standard for brain scanning.
Tumor tissue is denser than healthy tissue and this affects waters natural ability to permeate it. Right now diffusion MRI distorts the location of the actual tumor by up to a half an inch or 1.2cm. This problem is called a “magnetic field artifact”. This magnetic distortion is enough to complicate surgery who need to know how far a tumor extends beyond the prostate or how deeply it is located in relation to closely located nerve bundles.
RSI-MRI is measureable better than contrast MRI for the detection of Prostate Tumors
The authors describe the results of contrast-enhanced MRI and RSI-MRI in 28 patients with established prostate disease who had already undergone both types of scans before radio prostatectomy. This concluded that RSI-MRI corrected the magnetic field distortion associated with diffusion MRI enough to make it more effective than contrast-enhanced MRI to locate and size tumors of the prostate.
In the journal Frontiers in Oncology, the team reports how RSI-MRI may lend it’s self to the ability to predict tumor grade because the amount of water diseased cells can take into their nuclei differs with tumor grade. The ability to predict tumor grade with non-invasive imaging can spare patiente from aggressive prostate surgery and they can be monitored with routine scans instead.
The study was funded by the National Institutes of Health/National Institute of Biomedical Imaging and Bioengineering, the Department of Defense, Prostate Cancer Research Program among others.
Approximately 1 in 38 men will die of prostate cancer in the US. The disease is the second leading cause of death in men after lung cancer. The ACS estimates that in 2015 220,800 new cases of prostate disease will arise in the United States. There will be approximately 27,540 deaths.
Your chance of surviving Prostate Cancer reduces dramatically once the cancer spreads to other parts of the body. Tools to anticipate the stafe of the disease can make all the difference in terms of survival.