Quantitative 99m Tc-Pyrophosphate SPECT/CT evaluation of tafamidis response in a case of transthyretin cardiac amyloidosis.

Noninvasive diagnosis with technetium-99m pyrophosphate ( 99m Tc-PYP) scintigraphy has become established, but quantitative approaches for therapy monitoring remain under investigation.

We present a case of wild-type ATTR-CA in an 82-year-old man treated with tafamidis.

Planar and SPECT/CT imaging with 99m Tc-PYP demonstrated diffuse myocardial uptake (grade 3, H/CL 1.97).

Quantitative analysis with GI-BONE software yielded SUV max 4.2, amyloid deposition volume (amyloid deposition volume) 122 cm³, and total amyloid uptake (total amyloid uptake) 313.