MRI May Reveal Myeloma Response To Chemotherapy

Myeloma response to treatment could be assessed using magnetic resonance imaging

medwireNews: Magnetic resonance imaging (MRI) could reduce the need for repeat bone marrow biopsies in patients undergoing treatment for myeloma, suggest UK researchers.

Whole-body diffusion-weighted images (WB–DWI) of 26 myeloma patients taken before and after chemotherapy allowed two radiologists to each detect response with 86% sensitivity and 80% specificity compared with bone marrow or serum paraprotein and free light chain tests, the team reports in Radiology.

The researchers used a volumetric segmentation technique to produce Apparent Diffusion Coefficient (ADC) estimates – a quantitative measure of water diffusion within tissue. This showed that the mean ADC values increased in 95% of the patients who responded to treatment but decreased in those who did not respond.

A 3.3% increase in ADC indicated a myeloma response with 90% sensitivity and 100% specificity, while an 8% ADC increase was 70% sensitive and 100% specific for response.

Of note, ADC measurements of bone marrow were highly repeatable when conducted in seven myeloma patients and eight healthy volunteers, with an average variation of just 2.8% and 3.8%, respectively.

Furthermore, ADC values in the myeloma patient group significantly and negatively correlated with standard laboratory markers for myeloma response, the researchers add.

Concerns have been raised over an increase in signal intensity in DWI in patients who are given granulocyte colony stimulating factor, but the researchers found no imaging differences between patients who were and were not given the cytokine. However, they were unable to do further analysis due to the range of dosing and schedules for the cytokine that were used.

Discussing the study in a press release, author Nandita deSouza, from The Royal Marsden Hospital in Sutton, explained that the MRI results immediately show where and how severe myeloma 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,” she said.

Also commenting in the press release, author Faith Davies, from the Institute of Cancer Research, added: “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.”

Reference

Giles S, Messiou C, Collins D, et al. Whole-Body Diffusion-weighted MR Imaging for Assessment of Treatment Response in Myeloma. Radiology; Advance online publication January 21 2014. doi:10.1148/radiol.13130740

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