A new whole-body, diffusion-weighted magnetic resonance imaging (MRI) scan could improve care for myeloma - cancer of the white blood (plasma) cells, one of the most common forms of blood cancer - and reduce reliance on bone marrow biopsies, which can be painful for patients and often fail to show doctors how far the disease has spread.
Whole-body, diffusion-weighted MRI scans showed the spread of cancer throughout the bone marrow of patients with myeloma more accurately than standard tests. The scans also showed whether the patients were responding to cancer treatments.
In the study, 26 patients had whole-body, diffusion-weighted MRI scans before and after treatment. In 86% of cases, experienced doctors trained in imaging were able to correctly identify whether patients responded to treatment. The doctors also correctly identified those patients who weren't responding to treatment 80% of the time.
Using the scanning technique, doctors could pinpoint exactly where the cancer was in the bones, with the results available immediately. Conventional tests include bone marrow biopsies and blood tests but neither shows accurately where the cancer is present in the bones.
The researchers also assessed the visible changes on the MRI scans, using a measurement called the Apparent Diffusion Coefficient (ADC), which records how restricted water movement is within tissues. Changes in this measurement correctly identified treatment response for 24 of 25 myeloma patients.
The new 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.
Professor Nandita deSouza, 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 from all the bones in the entire body for myeloma in one scan without having to rely on individual bone X-rays. It enables us to measure the involvement of individual bones and follow their 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 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, said, "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 doctors to make more informed decisions. With this new scan, if a treatment isn't working the patient can be moved onto new therapies that might be more effective much more quickly.
"This is a small study, so our next step will be to try out the technology in more patients and refine it. In the future we hope this new tool will help doctors extend the life of more myeloma patients. "