The aims of this study were to evaluate the diagnostic performance of 18F-florbetaben PET/CT for detecting amyloid deposits in patients with multiple myeloma (MM) and to identify the optimal PET analysis method.
Fourteen patients with MM were prospectively enrolled (6 with amyloidosis, 8 control subjects). Dynamic imaging of the kidneys was performed for 20 minutes, and the retention ratio was obtained. At 90 minutes after injection, PET was performed. All images were assessed qualitatively and quantitatively, and the SUVmax, SUVmean, and SUVratio were obtained. Variables were compared between the amyloidosis group and the control group. Amyloid deposition was confirmed according to international consensus guidelines.
Tracer uptake was abnormal in all patients with amyloidosis. The visual detection rate was excellent (100%) in the heart, stomach, and tongue but limited in the kidneys (50%) and poor (0%) in the esophagus, liver, and colon. 18F-florbetaben PET/CT identified 13 unexpected cases of abnormal uptake, confirming further amyloid deposition. Both spherical and manual volumes of interest showed similar diagnostic performance when evaluating amyloidosis in target organs. There was no significant difference in diagnostic performance between the SUVmax, SUVmean, and SUVratio.
18F-florbetaben PET/CT can accurately detect systemic amyloid deposits in patients with MM. 18F-florbetaben PET/CT was particularly useful in the heart, stomach, and tongue but of limited value in the esophagus, liver, and colon. 18F-florbetaben PET/CT can provide clinical information on organ involvement and could replace pathologic examination for diagnosis of amyloidosis in the future.