Imaging Measurable (Minimal) Residual Disease in Multiple Myeloma

AbstractPurpose of ReviewThe availability of effective anti-myeloma therapies has led to the concept of new response categories that define responses deeper than conventionally defined complete response (CR). In cases of CR, deepest response, defined as minimal residual disease (MRD)-negative status, has been independently associated with prolonged progression-free survival and overall survival. In spite of an unmeasurable MRD, most patients eventually relapse. Because current methodology using flow cytometry or gene sequencing focuses on sampling MRD primarily from bone marrow, the low-level disease that may be present at other places in the skeleton and/or at extra-skeletal sites could be ultimately responsible for clinical relapse. Relevantly, sensitive imaging has the potential to complement MRD assessment by providing a complete picture of the entire bone/bone marrow compartment and extramedullary sites.Recent FindingsThe International Myeloma Working Group (IMWG) has come up with new response categories of MRD negativity with or without the absence of disease on imaging. Multiple studies support the notion that FDG-PET has higher specificity over MRI as MRD assessment adjunct because the detection of FDG-PET-positive lesions has prognostic value in patients with multiple myeloma at diagnosis and at time of relapse. MR techniques, including functional variations, and new PET tracers add additional information for MRD evaluation.SummaryWe provide an overview discussing th...

Source: Current Radiology Reports - October 20, 2016 Category: Radiology Source Type: research