Guidelines for the use of imaging in the management of patients with myeloma

Abstract

Summary The role of imaging in myeloma has gained increasing importance over the past few years. The recently revised definition of myeloma from the International Myeloma Working Group (IMWG) includes cross sectional imaging as a method to define bone disease and also incorporates its use in the disease definition for patients with suspected smouldering myeloma. The National Institute for Health and Care Excellence myeloma guidelines also recommend cross sectional imaging for patients with suspected myeloma. There is also increasing use of imaging in disease assessments and the International Myeloma Working Group has recently incorporated imaging in defining new response categories of minimal residual disease negativity, with or without imaging‐based evidence of disease. Plain X‐rays have previously been the standard imaging modality included in a myeloma work up at presentation but evidence is mounting for use of cross‐sectional modalities such as computed tomography (CT), magnetic resonance imaging (MRI) and 18fluoro‐deoxyglucose (18F‐FDG) positron emission tomography (PET)/CT. Funding and therefore availability of newer imaging techniques remains a barrier. Here, we propose an evidence‐based approach to the use and technical application of the latest imaging modalities at diagnosis and in the follow‐up of patients with myeloma and plasmacytoma.

Applications of PET‐MRI in musculoskeletal disease

“…MRI has been proven to be more sensitive in depicting MM lesions than radiographs, except for rib lesions . Up to 50% of patients with a normal radiographic skeletal survey have lesions depicted on MRI . On MRI, myelomatous lesions appear as T 1 hypointense areas of marrow replacement, with increased signal on T 2 or short tau inversion recovery (STIR)‐weighted images.…”

“…On MRI, myelomatous lesions appear as T 1 hypointense areas of marrow replacement, with increased signal on T 2 or short tau inversion recovery (STIR)‐weighted images. Five patterns of marrow involvement have been recognized: normal, focal, diffuse (homogenous or heterogeneous), variegated (also referred to as “salt and pepper”), or a combination thereof . Importantly MRI depicts marrow infiltration and replacement, while radiographs and CT illustrate osseous destruction, and because of this MRI has superior detection of bone marrow involvement compared with LDWBCT or PET/CT, with a specific advantage in the diffuse patterns of involvement .…”

“…Like MRI, FDG PET/CT is more sensitive than radiographs, and performs equally well to MRI in detecting focal lesions, but is inferior for detecting diffuse disease . Some studies have shown correlation between SUVmax on PET/CT and bone marrow cellularity and plasma cell ratios on bone marrow biopsy sample .…”

“…66 Up to 50% of patients with a normal radiographic skeletal survey have lesions depicted on MRI. 67,68 On MRI, myelomatous lesions appear as T 1 hypointense areas of marrow replacement, with increased signal on T 2 or short tau inversion recovery (STIR)-weighted images. Five patterns of marrow involvement have been recognized: normal, focal, diffuse (homogenous or heterogeneous), variegated (also referred to as "salt and pepper"), or a combination thereof.…”

“…Five patterns of marrow involvement have been recognized: normal, focal, diffuse (homogenous or heterogeneous), variegated (also referred to as "salt and pepper"), or a combination thereof. 67 Importantly MRI depicts marrow infiltration and replacement, while radiographs and CT illustrate osseous destruction, and because of this MRI has superior detection of bone marrow involvement compared with LDWBCT or PET/CT, with a specific advantage in the diffuse patterns of involvement. [69][70][71] Incorporation of DWI results in superior lesion conspicuity compared with conventional STIR and contrast-enhanced MRI, 72,73 and ADC values can be used with excellent accuracy (90% sensitivity and 93% specificity) to differentiate diseased and normal marrow.…”