RT Journal Article
SR Electronic
T1 Comparative evaluation of F-18 FLT PET/CT and F-18 FDG PET/CT in patients with newly diagnosed thoracic sarcoidosis
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 36
OP 36
VO 58
IS supplement 1
A1 Norikane, Takashi
A1 Yamamoto, Yuka
A1 Maeda, Yukito
A1 Noma, Takahisa
A1 Dobashi, Hiroaki
A1 Nishiyama, Yoshihiro
YR 2017
UL http://jnm.snmjournals.org/content/58/supplement_1/36.abstract
AB 36Objectives: F-18 FDG (FDG) PET has been used in sarcoidosis for diagnosis and determination of the extent of the disease. However, assessing inflammatory lesions in cardiac sarcoidosis using FDG can be challenging because the FDG accumulates physiologically in normal myocardium. 3'-deoxy-3'-F-18 fluorothymidine (FLT) has been investigated as a promising PET tracer for evaluating tumor proliferative activity. In contrast to FDG, FLT uptake in normal myocardium is low. The purpose of this study was to compare the uptake of FLT and FDG in the evaluation of cardiac and pulmonary involvement in patients with newly diagnosed thoracic sarcoidosis.Methods: Nineteen patients with newly diagnosed thoracic sarcoidosis were examined. FLT and FDG PET/CT studies were performed at 1 h after each radiotracer injection. The patients fasted for at least 18 h before FDG PET/CT, although no special dietary instructions were given to them before FLT PET/CT. We evaluated FLT and FDG uptake visually and semiquantitatively using standardized uptake value (SUV).Results: Two patients had only cardiac lesions, 11 had both cardiac and pulmonary lesions, and 6 had only pulmonary lesions. In the visual assessment of cardiac sarcoidosis, 4/19 FDG scans were rated as inconclusive because the FDG pattern was diffuse. In contrast, no FLT scans were rated as inconclusive. FDG PET/CT detected 11 of 11 (100%) clinically observed cardiac lesions. The mean ± SD of the SUV in cardiac lesions was 8.45±3.50. FDG PET/CT detected all 17 (100%) clinically observed pulmonary lesions. The mean ± SD of the SUV in pulmonary lesions was 10.74±5.55. FLT PET/CT detected 12 of 13 (92%) clinically observed cardiac lesions. The mean ± SD of the SUV in cardiac lesions was 3.14±0.89. FLT PET/CT detected all 17 (100%) clinically observed pulmonary lesions. The mean ± SD of the SUV in pulmonary lesions was 5.54±2.16.Conclusion: The results of this clinical study suggest that FLT PET/CT can detect pulmonary lesions to a degree similar to that of FDG PET/CT. Furthermore, FLT PET/CT, even without the usually necessary fasting contributes to a better evaluation of cardiac involvement in sarcoidosis patients. Research Support: I have no financial relationships to disclose.