Standard imaging techniques, such as PET and CT scans, are used to assess the development of cancer in children. However, these imaging methods can expose children to radiation that increases their risk of secondary cancers later in life. Now, new research has detailed a new whole-body imaging technique that could eliminate this risk.
In a study recently published in The Lancet Oncology, researchers from Stanford University School of Medicine in California tested a new whole-body diffusion-weighted magnetic resonance imaging (MRI) technique.
The imaging method uses ferumoxytol – an iron supplement – to enhance the visibility of tumors. Ferumoxytol is made up of tiny superparamagnetic iron oxide particles that are detected with MRI.
The research team, led by Dr. Heike Daldrup-Link, notes that computed tomography (CT) and 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT scans are the main techniques used to see what stage cancers are at and to determine the best treatment method.
But Dr. Daldrup-Link says previous research has demonstrated the secondary cancer risks associated with these techniques.
According to the study background, ionizing radiation – high frequency radiation that has enough energy to damage cells’ DNA – in early childhood has been shown to triple the risk of lifetime cancer, compared with adults exposed to the radiation from the age of 30.
Furthermore, the investigators note that cumulative radiation exposure from diagnostic CT scans may almost triple the risk of secondary leukemia and brain cancer later in life.
Dr. Daldrup-Link points out that children are much more sensitive to radiation than adults, and they are more likely to experience secondary cancers because they will live for a longer period after exposure.
The researchers wanted to see how their new whole-body MRI technique – which uses no radiation exposure – compared in terms of diagnostic accuracy with the standard 18F-FDG PET/CT approach.
Average radiation exposure was confirmed as zero for the whole-body MRI technique, while the 18F-FDG PET/CT method exposed patients to 12.5 millisieverts (mSv).
The investigators found that the diagnostic accuracy of the whole-body MRI technique was 97.2%, compared to 98.3% in the 18F-FDG PET/CT method. The whole-body MRI also showed similar sensitivities and specificities to the 18F-FDG PET/CT, at 93.7% vs. 90.8% and 97.7% vs. 99.5%, respectively.
Commenting on the findings, the researchers say:
“Present techniques used for diagnosis and treatment, albeit effective, might bear certain risks and thus do not meet our high standards on patient care.
This new imaging test might solve this conundrum of the need for diagnostic cancer staging procedures and concurrent risk of secondary cancer development later in life.”
However, in a comment piece linked to the study, Thomas C. Kwee, of the University Medical Centre Utrecht in the Netherlands, notes that although the new whole-body MRI technique has shown success in this study, “further work is needed before it can become a clinical alternative to 18F-FDG PET/CT.”
And Dr. Daldrup-Link told Medical News Today that the research team plans to do just that.
She said the team has already formed a collaboration with six centers in the US, including the University of California, San Francisco, and Stanford University, in order to test the new MRI imaging method against radiotracer-based staging examinations.
“We are in the process of applying for funding at the moment and if all goes well, might be able to start the multi-center trial this fall. We already received requests from two centers in Europe who want to join in as well,” said Dr. Daldrup-Link.
Medical News Today recently reported on a study detailing a new imaging technique called mass spectrometry imaging (MSI) – a method the researchers say could speed up cancer diagnosis.