Quantitative 99mTc-DPD SPECT/CT in patients with suspected ATTR cardiac amyloidosis: Feasibility and correlation with visual scores

Abstract

Purpose: While a visual interpretation of ^99mTc-DPD scintigraphy by means of Perugini score can provide a reliable diagnosis of transthyretin-related (ATTR) cardiac amyloidosis (CA), a quantitative approach is expected to play a major role in risk stratification and therapy evaluation. The aim of our study was to test the feasibility of a quantitative assessment and to correlate various parameters to Perugini score.

Methods: in this retrospective study, consecutive patients underwent a ^99mTc-DPD whole-body bone scintigraphy and a SPECT/CT of the thorax. XSPECT-QUANT software was used to quantify the DPD uptake in the heart.

Results: Thirteen patients were included. CA was confirmed in 8 and rejected in 5. Myocardial SUVmax and SUVpeak showed a fairly strong correlation with Perugini score (both ρ = .71, P = .006). Same held true for to-bone normalized values (both ρ = .75, P = .003). There was a great degree of overlap for quantitative values in patients with Perugini score 2 and 3.

Conclusion: Quantitative ^99mTc-DPD SPECT/CT in suspected ATTR CA patients is feasible and allows for a more accurate assessment of myocardial uptake.

Keywords: 99mTc-DPD SPECT/CT; ATTR cardiac amyloidosis; Bone scan; Metabolic disease.