In an effort to help detect prostate cancer in men, a team of researchers at University of California, San Diego School of Medicine and University of California, San Diego is improving magnetic resonance imaging (MRI) methods to be more specific in diagnosing cancer. This new technique may prove vital in diagnosing cases of prostate cancer, the leading cause of newly diagnosed cancers and the second leading cause of cancer death among men.
“This new approach is a more reliable imaging technique for localizing tumors,” said Rebecca Rakow-Penner, MD, first author of a study related to this research, in a news release. “It provides a better target for biopsies, especially for smaller tumors.”
Dr. Penner and colleagues at UCSD and UCLA compiled their work into the article “Novel Technique for Characterizing Prostate Cancer Utilizing MRI Restriction Spectrum Imaging: Proof of Principle and Initial Clinical Experience with Extraprostatic Extension,” published in Prostate Cancer and Prostatic Diseases, which is part of the Nature Publishing Group.
The team’s work used diffusion MRI to measure the diffusion of water in the prostate. This is in opposition to the current standard of using contrast enhanced MRI to highlight blood flow with an injected contrast agent. Although cancer cells require an increased level of blood flow, the increase in blood flow within tumors is often not significant compared with surrounding healthy tissue blood flow.
Diffusion MRI may help detect “hidden” tumors because dense, cancerous tissue inhibits the mobility of water, allowing greater delineation between cancerous and healthy tissue. But even so, diffusion MRI produces magnetic field artifacts that can lead a surgeon astray by as much as a half inch when assessing cancer spread beyond the prostate.
To mitigate these artifacts, Dr. Rakow-Penner and colleagues created an approach called restriction spectrum imaging-MRI (RSI-MRI). This technique analyzes water diffusion inside tumor cells, correcting for magnetic field artifacts. Thus, more accurate plots of tumor location are accessible to surgeons and clinicians treating prostate cancer patients.
An added benefit of this research is that it may change the way prostate cancer patients are treated. RSI-MRI may be able to predict tumor grade, according to another article published in Frontiers in Oncology. In “MR Water Quantitative Priors Improves the Accuracy of Optical Breast Imaging,” the research team reduced quantification errors by as much as 20%. There was a correlation between high restricted water volume in cell nuclei and high tumor grade.
“If by imaging we could predict the tumor grade, we may be able to spare some patients from prostate resection and monitor their cancer with imaging,” said Robert Reiter, MD, a professor of oncology at UCLA. Co-author Christopher J. Kane, MD, a professor of urology at UCSD, also noted, “Prostate cancer can often be an indolent disease, where a patient may only require surveillance rather than aggressive surgery.”
Overall, David S. Karow, MD, PhD, principal investigator of the study, indicated, “Doctors at UCSD and UCLA now have a noninvasive imaging method to more accurately assess the local extent of the tumor and possibly predict the grade of the tumor, which can help them more precisely and effectively determine appropriate treatment.”