Could this new imaging test help doctors identify more aggressive tumors before they spread in the body and enable them to plan radiotherapy and other cancer treatments more effectively?
A team from the University of Manchester and Institute of Cancer Research in London ventured to develop magnetic resonance imaging (MRI) technology – dubbed as oxygen-enhanced MRI – to determine oxygen deprivation sites in tumors.
Hypoxia or the lack of oxygen usually signals the aggressive growth of cancers, and stimulates blood vessel growth in tumors such that cancer cells spread more efficiently to other bodily parts.
Dr. Simon Robinson, study co-lead author and Institute of Cancer Research’s team leader in magnetic resonance, said their technique will map out areas of oxygen deprivation, which are more likely to be more aggressive and resistant to cancer therapies such as radiation and chemotherapy.
“Our study provides strong pre-clinical evidence to validate the use of oxygen-enhanced MRI to identify, quantify and map tumor hypoxia,” he added.
With this technology, radiotherapy can be better planned to boost X-ray doses delivered to risky tumor areas, and there can be novel ways to monitor the effectiveness of such cancer drugs or treatment.
Cancer Research UK senior science information manager Nell Barrie explained that cancer cells running out of oxygen are more likely to spread from the originating tumor, making treatment much more difficult. Combining imaging and radiotherapy can then benefit patients in the years ahead of them.
In the United Kingdom, over 330,000 individuals are diagnosed with cancer annually, with a bit more than 160,000 deaths. Preventable cancer cases are currently at 42 percent and cancer survival has doubled in the past four decades.
Oxygen-enhanced MRI watches for changes in image intensity caused by changes in the amount of dissolved oxygen in blood plasma and fluid in tissues, when pure oxygen is inhaled. Some tissues consume the extra oxygen more quickly than the rest, which reflect in MRI scans as more intensively changing areas.
According to researchers, images of oxygen-deprived regions would change intensity less significantly than better oxygenated ones.
To test the research, they implanted cancer cells into mice and are now further developing it via clinical studies of human cancer patients. They also showed that their technology worked for less oxygen-deprived tumors by imaging slower-growth kidney tumor and tumors grown from bower cancer cells.
"There is currently no validated, affordable and widely available clinical imaging technique that can rapidly assess the distribution of tumor hypoxia,” said co-lead author Dr. James O’Connor, adding that their findings will soon be useful for conventional clinical MRI scanners.
The study was published Thursday in the journal Cancer Research.
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