Cancer scan avoids exposing younger patients to radiation
A new method of scanning young cancer patients for tumours has been developed that avoids exposing them to potentially harmful radiation, US researchers say.
A team from the Stanford University School of Medicine has developed a new way of using magnetic resonance imaging (MRI) to look for cancer in children and young people, rather than the usual positron emission tomography/computed tomography (PET/CT) scan.
PET-CT technology is effective at detecting cancer but exposes patients to radiation, which can increase the risk of secondary cancers in later life.
The new MRI-based method uses an iron supplement called ferumoxytol and helps tumours stand out when scanned.
"This technique could improve diagnosis of some children and young adults with cancer, but these are early days" - Dr James O'Connor
Dr James O'Connor, a Cancer Research UK clinician scientist, said: “MRI already plays a vital role in the diagnosis, staging and follow-up of patients with cancer and other diseases.
“This study combines two new MRI techniques and shows potential for effective detection of widespread cancer without exposing patients to high doses of radiation as currently happens with PET-CT.”
He said the technique could improve diagnosis of some children and young adults with cancer, but that it won’t change clinical practice until further studies have been carried out to ensure that the technique is safe and reliable.
These cancers start off in the immune system and the bones, respectively, and both cancers can spread throughout tissues such as bone marrow, lymph nodes, liver and spleen.
The new contrast agent used with the MRI scan consisted of iron oxide nanoparticles. On an MRI scan, the nanoparticles cause blood vessels to appear brighter. They also cause healthy bone marrow, lymph nodes, liver and spleen to appear darker, making tumours stand out.
The researchers found that the images generated from the MRIs revealed approximately as much information as the PET-CT scans. The PET-CTs detected 163 of 174 total tumours in the 22 patients, while the MRIs found 158 of 174 tumours.
- Klenk C. et al. (2014) Ionising radiation-free whole-body MRI versus 18F-fluorodeoxyglucose PET/CT scans for children and young adults with cancer: a prospective, non-randomised, single-centre study, The Lancet Oncology, DOI: 10.1016/S1470-2045(14)70021-X