ABC | Volume 114, Nº2, February 2020

Update Update of the Brazilian Guideline on Nuclear Cardiology – 2020 Arq Bras Cardiol. 2020; 114(2):325-429 A potential bone radiotracer for PET amyloid imaging is sodium fluoride labeled with 18 F, or Sodium fluoride- 18 F. It has been described in single case series, whereas another study identified no increase in uptake of this tracer with TTR CA, 450-452 indicating the need for further studies to investigate the potential value of PET/CT with Sodium fluoride- 18 F for CA. A small amount of available data has demonstrated the limited application of FDG- 18 F - PET/CT for evaluation of CA. 453,454 Up to the present moment, the most promising alternatives include other specific amyloid markers, such as the Pittsburgh B compound labeled with carbon-11 (PIB- 11 C), 455,456 as well as other compounds labeled with 18 F, such as Florbetapir 457,458 and Florbetaben. 459 All studies have reported promising results for diagnosis of CA, given that PIB- 11 C presents uptake in AC. It has additionally been demonstrated that PIB- 11 C has lower uptake in patients who have been treated with chemotherapy, in comparison with patients still undergoing treatment. Thus, PIB- 11 C - PET has the potential to be used for therapeutic monitoring of patients with light-chain CA as a marker of disease activity. 460 14.7. Final Considerations New applications of nuclear medicine in cardiology (Table 32) represent an important area which is little explored in Figure 61 – Scintigraphy with Pyrophosphate- 99m Tc (left: planar imaging of the anterior thorax; right: axial cross section of the tomography image) demonstrated severe radiopharmaceutical uptake in the left ventricle (arrows) in a patient with confirmed transthyretin cardiac amyloidosis. Personal source (courtesy of Dr. Rafael Willain Lopes). Figure 62 – Quantification of uptake in planar imaging of anterior thorax scintigraphy with Pyrophosphate- 99m Tc. The image on the left represents a negative study, without uptake in the cardiac area. The image on the right represents a study positive for amyloidosis, with accentuated diffuse uptake in the left ventricle. For the purpose of quantification, circular regions of interest (ROI) have been drawn in both hemithoraxes, and the uptake ratio of the radiopharmaceutical between the ROI in the cardiac area (C) and the ROI in the contralateral (Cl) hemithorax. Results over 1.5 suggest TTR amyloidosis. The visual uptake score was equal to 1 in the image on the left and 3 in the image on the right. Source: INCOR, FMUSP, SP. C/Cl Ratio = 1.14 Visual: 1 (< rib) C/Cl Ratio = 1.58 Visual: 3 (< rib) C/Cl R = 1.14 C/Cl R = 1.58 410