99mTc-DPD scintigraphy and SPECT/CT in patients with AL and ATTR type amyloidosis: Potential clinical implications

• Published in: Medicine (Baltimore) Vol. 99; no. 4; p. e18905
• Main Authors: Lee, Joohee, Kim, Kihyun, Choi, Jin-Oh, Kim, Seok Jin, Jeon, Eun-Seok, Choi, Joon Young
• Format: Journal Article
• Language: English
• Published: United States the Author(s). Published by Wolters Kluwer Health, Inc 01.01.2020; Wolters Kluwer Health
• Subjects: Adult; Aged; Amyloid Neuropathies, Familial - diagnostic imaging; Female; Humans; Immunoglobulin Light-chain Amyloidosis - diagnosis; Male; Middle Aged; Observational Study; Organotechnetium Compounds - administration & dosage; Radionuclide Imaging - methods; Single Photon Emission Computed Tomography Computed Tomography - methods; Whole Body Imaging
• ISSN: 0025-7974; 1536-5964; 1536-5964
• DOI: 10.1097/MD.0000000000018905

Although pathological confirmation is the gold standard for diagnosis of amyloidosis, there is a need for a relevant imaging modality to identify involved organs and evaluate disease extent. Thus, we prospectively investigated imaging findings of Tc-DPD scintigraphy in AL and ATTR amyloidosis.A total of 21 subjects with pathologically confirmed AL or ATTR amyloidosis were included. Pretreatment whole body Tc-DPD planar scanning and regional SPECT/CT were performed in all subjects. For allegedly involved organs, Tc-DPD uptake was visually and semi-quantitatively evaluated on a 4-point scale (grade 0: no uptake, 1: uptake less than spine, 2: uptake similar to spine, and 3: uptake greater than spine).There were 29 organs involved in AL and 12 in ATTR. Significant Tc-DPD uptake was found in 24 organs (sensitivity = 82.8%) in AL and 9 organs (sensitivity = 75.0%) in ATTR. Additional SPECT/CT was helpful to ensure abnormal DPD uptake in the involved organs, which was uncertain by attenuation in planar imaging. Degree of Tc-DPD uptake was significantly higher in ATTR compared with AL amyloidosis (P = .017). Diffuse soft tissue uptake with photon defects in the liver area was found only in ATTR amyloidosis.This study showed that Tc-DPD scintigraphy might have capacity to differentiate between AL and ATTR subtypes with good sensitivity in various organs involving primary systemic AL and ATTR amyloidosis. Additional SPECT/CT significantly improved the diagnostic efficacy of Tc-DPD scintigraphy.