Diagnostic Performance of Positron Emission Tomography in the Assessment of Systemic Amyloidosis: A Systematic Review and Meta-Analysis.

BACKGROUND

Positron emission tomography (PET) imaging with radiotracers can detect amyloid deposits in multiple organs. We conducted a systematic review and meta-analysis to evaluate the diagnostic performance of PET in patients with systemic amyloidosis.

METHODS

We searched PubMed, Cochrane, Embase, and Web of Science databases using the following keywords: "systemic amyloidosis" and "PET". Studies evaluating organ involvement in systemic amyloidosis using PET were included. The pooled relative risk (RR) values for each affected organ were calculated. Sensitivity, specificity, positive and negative likelihood ratios (LRs+ and LRs-), and diagnostic odds ratios (DORs) were individually calculated to assess cardiac involvement by PET, and a summary receiver operating characteristic (SROC) curve was generated. The diagnostic performance of PET was compared in separate subgroup analyses based on the type of radiotracer and amyloidosis subtype.

RESULTS

Among 10 studies, the pooled RR values for PET detecting organ involvement in the bone marrow, central nervous system (CNS), heart, lungs, muscles, pancreas, salivary glands, spleen, thyroid, and tongue were statistically significant. In the seven studies on cardiac involvement, the pooled sensitivity and specificity were 0.98 and 0.61, respectively, with an area under the curve (AUC) of 0.8954. Subgroup analysis showed 124I-Evuzamitide had the highest sensitivity (0.98), while 11C-Pittsburgh Compound-B (11C-PIB) had the highest specificity (0.84). PET imaging detected cardiac involvement in light chain amyloidosis (AL) more effectively than in transthyretin amyloidosis (ATTR), with a pooled RR of 0.79 (p = 0.004).

CONCLUSION

PET imaging has significant clinical value in assessing organ involvement in systemic amyloidosis, particularly for the early detection of cardiac involvement.