Comparison of the diagnostic performance and impact on management of 18F-FDG PET/CT and whole-body MRI in multiple myeloma

Abstract

Purpose Comparative data on the impact of imaging on management is lacking for multiple myeloma. This study compared the diagnostic performance and impact on management of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and whole-body magnetic resonance imaging (WBMRI) in treatment-naive myeloma. Methods Forty-six patients undergoing 18F-FDG PET/CT and WBMRI were reviewed by a nuclear medicine physician and radiologist, respectively, for the presence of myeloma bone disease. Blinded clinical and imaging data were reviewed by two haematologists in consensus and management recorded following clinical data ± 18F-FDG PET/CT or WBMRI. Bone disease was defined using International Myeloma Working Group (IMWG) criteria and a clinical reference standard. Per-patient sensitivity for lesion detection was established. McNemar test compared management based on clinical assessment ± 18F-FDG PET/CT or WBMRI. Results Sensitivity for bone lesions was 69.6% (32/46) for 18F-FDG PET/CT (54.3% (25/46) for PET component alone) and 91.3% (42/46) for WBMRI. 27/46 (58.7%) of cases were concordant. In 19/46 patients (41.3%) WBMRI detected more focal bone lesions than 18F-FDG PET/CT. Based on clinical data alone, 32/46 (69.6%) patients would have been treated. Addition of 18F-FDG PET/CT to clinical data increased this to 40/46 (87.0%) patients (p = 0.02); and WBMRI to clinical data to 43/46 (93.5%) patients (p = 0.002). The difference in treatment decisions was not statistically significant between 18F-FDG PET/CT and WBMRI (p = 0.08). Conclusion Compared to 18F-FDG PET/CT, WBMRI had a higher per patient sensitivity for bone disease. However, treatment decisions were not statistically different and either modality would be appropriate in initial staging, depending on local availability and expertise.

Prospective Evaluation of Whole-Body MRI versus FDG PET/CT for Lesion Detection in Participants with Myeloma

“…Approaches such as comparison of WB FDG PET/CT against standard MRI of the spine and pelvis without diffusion-weighted imaging have previously shown no difference in lesion detection (32). However, our analysis is in line with results reported for retrospective series and a recent prospective study (18) comparing WB-MRI with FDG PET/CT; our work and others' firmly support wider use of WB-MRI for myeloma (17,33). This is further supported by published evidence on high interobserver agreement in WB-MRI reporting (34,35), interpretation of potential false-positive findings, and established international consensus criteria (15), together positioning WB-MRI as a new imaging standard for myeloma.…”

“…Unfortunately, MRI studies that have not included diffusion-weighted sequences cannot reliably distinguish active from inactive sites and are prone to false-positive findings. One recent prospective study (18) compared WB-MRI, including diffusion-weighted MRI, with FDG PET/CT, and WB-MRI was found to have a higher sensitivity for detecting focal bone lesions. Hence, further confirmation of WB-MRI with diffusion-weighted MRI as a staging tool in myeloma will help to establish its wider deployment in clinical practice.…”

18F-FDG PET/CT and MRI in the Management of Multiple Myeloma: A Comparative Review

“…Similar results were found by two other recent studies (43,44). It was also shown that CT helps improve the diagnosis of bone involvement in patients with a low 18 F-FDG uptake (44,45). Comparison of the detectability of FLs showed that, overall, DW-MRI detects more FLs than does 18 F-FDG PET/CT (44)(45)(46).…”

Association of loss of spleen visualization on whole-body diffusion-weighted imaging with prognosis and tumor burden in patients with multiple myeloma

“…Highly cellular tissues such as tumors (where water diffusion is restricted), or tissues where the proportion of water density is higher than cellular density (such as in a cerebral infarction), result in high signal intensity on DWI with high b -values compared to the normal surrounding tissue. In patients with MM, the use of WB-DWI in diagnosis is superior to whole-body radiographs 4 and is equal to or more sensitive than PET/CT for the detection of focal lesions 1 , 5 , 6 . Although WB-DWI is mainly used in diagnostic process, there are several reports regarding the use of WB-DWI to monitor the patient’s response to treatment 7 – 9 .…”