A recently published paper (Giles SL et al. Whole-Body Diffusion-weighted MR Imaging for Assessment of Treatment Response in Myeloma. Radiology. 2014:131529 doi) from a group of researchers at The Institute of Cancer Research, London and The Royal Marsden NHS Foundation Trust in the UK describes the usefulness of whole-body diffusion weighted MRI scans for monitoring the treatment response in patients with myeloma, one of the most common blood cancers.
The whole-body, diffusion-weighted MRI scans showed the spread of cancer throughout the bone marrow of myeloma patients more accurately than standard tests. These include bone marrow biopsies and blood tests but do not show accurately where the cancer is present in the bones. 
The scans also showed whether the patients were responding to cancer treatments. In the study, 26 myeloma patients had whole-body, diffusion-weighted MRI scans carried out before and after treatment. In 86% of cases, experienced radiologists were able to correctly identify which patients responded to treatment, and in 80% of the cases to also correctly identify patients who weren’t responding to treatment. Using the scanning technique, the sites of cancerous lesions in the bones could be identified, in contrast to conventional tests. By measuring the Apparent Diffusion Coefficient (ADC) the researchers also assessed visible changes; this approach correctly identified treatment response for 24 out of 25 myeloma patients. The DW MRI scan was able to visualize cancer in almost all bones in the body, with only the skull remaining difficult to image partly because of the frequency of metal dental implants and fillings. The researchers also found the new methods were suitable for more patients than conventional tests; for example, seven patients had bone marrow biopsies but their samples were found to be inadequate for analysis. Performing another biopsy could be traumatic and painful, and may not provide any new information.
Dr Nandita de Souza, Professor of Translational Imaging at The Institute of Cancer Research and Honorary Consultant at The Royal Marsden, said: “This is the first time we’ve been able to obtain information for myeloma from all the bones in the entire body in one scan without having to rely on individual bone X-rays. It enables us to measure the involvement of individual bones and follow the response to treatment.
“The results can be visualized immediately; we can look on the screen and see straight away where the cancer is and measure how severe it is. The scan is better than blood tests, which don’t tell us in which bones the cancer is located. It also reduces the need for uncomfortable biopsies, which anyway don’t reveal the extent or severity of the disease.”
Dr Faith Davies, member of the Myeloma Targeted Treatment Team at The Institute of Cancer Research and Honorary Consultant at The Royal Marsden, added: “Myeloma can affect bones anywhere in the body, which is why this study is so important. We’ve shown that whole body MRI scans can accurately monitor how myeloma patients are responding to treatment, allowing more informed decisions. With this type of scan, we can decide if a treatment isn’t working so the patient can be moved onto new therapies that might be more effective much more quickly”.