Objectives: To describe FDG-PET/CT in amyloid light-chain (AL) amyloidosis.
Methods: We describe a French multicenter study which included patients with AL amyloidosis who had undergone a FDG-PET/CT during follow-up.
Results: Ten patients with AL amyloidosis (median age 62 years [59-85]) were analyzed. AL amyloidosis was of λ-type in 7/10 cases (70%) and localized amyloidosis in 4/10 cases (40%). AL amyloidosis was primary in 7/10 (70%) cases and associated with Waldenstrom's macroglobulinemia (n = 2) and plasmocytoma (n = 1) in the remaining cases. Median delay between diagnosis and PET was 1 month [0-51]. PET was positive in seven (70%) patients and showed a median FDG SUV of 6.5 [ 4-15 ]. FDG uptakes with positive PET were localized in seven patients, namely in the nasopharynx (n = 3), bronchopulmonary (n = 2), duodenal, cutaneous, bone, joint and muscular areas (n = 1, each). FDG uptakes on PET were concordant with the known organ impairment in 6/7 cases (86%) and showed unknown nasopharyngeal and mesenteric localization in one case each. PET was negative in the patient with cardiac amyloidosis and two patients with pulmonary amyloidosis.
Conclusion: High FDG uptake may be present in patients with AL amyloidosis, however prospective studies are needed in order to determine the place of FDG PET in AL amyloidosis.