Whole Body, Diffusion-Weighted MRI Scan Could Optimize Bone Marrow Cancer Treatment

The new whole-body, diffusion-weighted MRI scans demonstrated the spread of cancer throughout the bone marrow of patients with myeloma, one of the most common forms of blood cancer, more effectively than conventional tests. The scans also showed whether the patients were responding to cancer treatments.

In the study, 26 patients had whole-body, diffusion-weighted MRI scanning before and after treatment. In 86% of patients, experienced doctors trained in imaging were able to correctly identify whether patients responded to treatment. In addition, they also accurately identified those patients who were not responding to treatment 80% of the time. Using the scanning technique, clinicians could target precisely where the cancer was in the bones, with the results available immediately. Conventional tests include bone marrow biopsies and blood tests; however, neither shows accurately where the cancer is present in the bones.

The researchers also evaluated the visible alterations 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 ADC is a quantitative measure of the random thermal movement of water protons within tissues. Water movement is more limited in tumors because their high cell density restricts the movement of extracellular water.

The new technology was able to image cancer in nearly all the 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 discovered that the new imaging techniques were suitable for more patients than conventional tests; for instance, 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.

Nandita deSouza, professor of translational imaging at the Institute of Cancer Research (ICR; London, UK) and honorary consultant at the Royal Marsden (London, UK), 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 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. ”

Julia Frater, Cancer Research UK’s (London) senior cancer information nurse, said, “Finding kinder ways to monitor how patients respond to treatment is really important, particularly in the case of myeloma where taking bone marrow samples can be painful. This research demonstrates how an advanced imaging technique could provide a whole-skeleton ‘snapshot’ to track the response of tumors in individual bones. Finding ways to make treatments gentler and improve the experience for patients is an important focus for Cancer Research UK and the research we fund.”

Related Links:
The Institute of Cancer Research