A chemical commonly called ‘baking soda’ which is found naturally in the body could be used to detect cancer with magnetic resonance imaging, according to Cambridge researchers.
Traditionally magnetic resonance imaging – or MRI – detects water and fat in the human body. By boosting MRI sensitivity more than 20,000 times – using a scanning technique developed by GE Healthcare – researchers can now image the molecules that cancer cells use to make energy and to grow.
This level of precision could be used to detect tumours and to find out if cancer treatments are working effectively at an earlier stage.
Almost all cancers have a lower pH than the surrounding tissue. Normally, the human body has a system of balancing chemicals with a low pH, acids, and chemicals with a high pH, alkalis, to maintain a constant, healthy pH level. In cancer, this balancing system is disturbed, and the tissue becomes more acidic.
Currently, there is no way to safely measure differences in pH in patients, but spotting these areas of acidity could be used to find cancers when they are very small.
Working with mice, the researchers found a new way to measure pH levels using this very sensitive MRI technique with a tagged form of bicarbonate. Bicarbonate, or baking soda, occurs naturally in the body, where it is involved in the acid-alkali balancing system.
Lead researcher Prof Kevin Brindle, from Cancer Research UK’s Cambridge Research Institute at Cambridge University, said that the technique could be used as a highly-sensitive early warning system for the signs of cancer. Establishing such tools is a major challenge in cancer research.
‘By exploiting the body’s natural pH balancing system, we have found a potentially safe way of measuring pH to see what’s going on inside patients. MRI can pick up on the abnormal pH levels found in cancer and it is possible that this could be used to pinpoint where the disease is present and when it is responding to treatment,’ he said.
Using MRI, they looked to see how much of the tagged bicarbonate was converted into carbon dioxide within the tumour. In more acidic tumours, more bicarbonate is converted into carbon dioxide.
Dr Ferdia Gallagher who is a Cancer Research UK and Royal College of Radiologists clinical training fellow, based at Cambridge University, said that if the technique proved to be safe and effective in cancer patients it had the potential to be a crucial tool in detecting cancer earlier, which is often the key to successful treatment.