New body scans help detect spread of myelomaBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g1170 (Published 29 January 2014) Cite this as: BMJ 2014;348:g1170
A new type of magnetic resonance imaging (MRI) scan may help to detect whether cancer cells have spread to the bones of patients with myeloma, avoiding the need for painful and repeated bone marrow biopsies, a small study has found.
The scan could also help doctors decide whether patients are responding to treatment, say the researchers, from London’s Institute of Cancer Research and Royal Marsden NHS Foundation Trust.
Myeloma is currently diagnosed and staged with radiography and regular MRI scans, but gauging the response of the disease to treatment often involves bone biopsies. However, even biopsies cannot pinpoint the severity of the cancer or its location in bones.
In soft tissue tumours the new whole body, diffusion weighted MRI scanning provides high contrast between normal and pathological marrow, and the researchers wanted to study the technique for assessing response to treatment. They reported their results in Radiology.1
Altogether 26 patients underwent whole body, diffusion weighted MRI before and after treatment. Experienced doctors trained in imaging correctly identified 18 of 21 patients who were responding to treatment and four of five patients who weren’t responding to treatment.
The new scan was able to visualise 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 assessed visible changes on the MRI scans by using a measurement called the apparent diffusion coefficient (ADC), which records restriction of water movement within tissues. They found that mean ADC rose in 19 of 20 patients who responded to treatment (mean increase 19.8% (SD 21.5%)) and fell in all five patients who did not respond (mean decrease 3.2% (SD 2.2%)). In one patient ADC analysis was not possible because of lack of visible bone marrow both before and after treatment. There was a significant correlation between change in ADC and change in laboratory markers of response (r=0.614; P=0.001).
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 visualised 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.”
Because of the small size of the study the next step is to test the technology in more patients, said the researchers.
Cite this as: BMJ 2014;348:g1170