Doctors are very interested in our ability to carry out dual-energy scans and have approached us for research projects as a result, reveals our lead CT, Dr Andrew Gogbashian.
Computed Tomography (CT) scans were first pioneered in the 1970s by Sir Godfrey Hounsfield at the EMI research facility in Middlesex, not far from Paul Strickland Scanner Centre. CT scans provided huge advances in the ability to monitor and diagnose cancer. But now, thanks to advances in technology and computer processing that would have sounded like science fiction back then, “dual-energy” CT scans can give doctors even more information about your cancer. This could help detect some types of cancers better, how cancer is responding to treatment – or even how some types of cancer might respond to chemotherapy. Apart from Paul Strickland Scanner Centre, only a select group of centres offer this type of CT scan, with most hospitals only able to offer patients standard CT scans.
Dr Andrew Gogbashian, our lead consultant radiologist for CT, said: “Sir Godfrey Hounsfield’s original intention was to scan with dual-energy CT scanning, but he and his colleagues didn’t have the technology or computing power.
“The concept is to use two energy sources to image the patient. A normal CT scanner uses one X-ray tube, but by using two energy sources simultaneously we can get more information from the body that could be important in diagnosing a patient or planning their treatment. The computing power can nowadays handle that double information quickly. What’s more, with the scanner we’ve got the radiation dose is the same as with a standard scanner and is considered ‘dose neutral’.”By doing the scans in a dual-energy mode we get extra information from body tissues that can help us better detect certain types of cancer. Research into melanoma (an aggressive type of skin cancer) has shown that dual-energy can be better in detecting metastases, which is when cancer has spread to multiple parts of the body. More and more research is confirming the usefulness of dual-energy CT in other types of cancer as well.”
CT scans are the most rapid tool for assessing tumour staging, and the dual-energy CT scan time is exactly the same as for a normal CT scan.
Dr Gogbashian said: “Dual-energy could help your radiologist identify a cancer or metastasis that was harder to see using the conventional technique. With the dual-energy technique we can produce colour coded maps that help in the detection process. With routine CT, colour maps are not produced, and it’s been shown that the colour maps can be useful for detecting more metastases, some of which are otherwise very difficult to see on black and white images.”
“We mainly scan patients with cancer and it helps us detect treatment responses in new ways that aren’t possible with standard scanners. We’ve been using dual-energy CT as a routine clinical tool for about 2 years now. You need a more advanced scanner that is more expensive and many hospitals could find it difficult to afford them.
“Because our charity supports cutting-edge technology and we have incredibly generous donors, we’re able to buy very advanced scanners for our patients and deliver the best technology available.”
According to Dr Gogbashian, there is growing interest in dual-energy CT amongst researchers. He said: “There’s more and more research happening with dual-energy and we hope that in the future there will be other breakthroughs.
“Research is increasingly showing that dual-energy CT can detect response to certain treatments earlier — which conventional CTs cannot predict. Sometimes a tumour may not change in size but it may change in blood flow and we can use dual-energy to help assess blood flow indirectly.”
Doctors are very interested in our ability to carry out dual-energy scans and have approached us for research projects as a result.”
Other uses
Dual-energy CT scanning is not just useful in cancers. Dr Gogbashian said: “It can, for example, help a patient with kidney stones avoid surgery by identifying whether they have a type of stone that is suitable to be treated with medication alone. It can also be used to identify subtle fractures in the bone marrow (which become more common as people become older), reducing the imaging artefacts that can occur when there is metal-work in the body, and it has become the gold-standard imaging assessment in identifying gout.
If you want to know if a dual-energy CT scan might be right for you, speak to your doctor or a member of your medical team.
