Feasibility and image quality of dual-isotope SPECT using 18F-FDG and (99m)Tc-tetrofosmin after acipimox administration.
Currently, with the rapidly increasing number of patients with heart failure due to chronic coronary artery disease, the need for viability studies to guide treatment in these patients is increasing. The most accurate method for viability assessment is metabolic imaging with (18)F-FDG with PET or SPECT. To obtain excellent image quality in all patients, the (18)F-FDG studies should be performed during hyperinsulinemic euglycemic clamping. However, this approach is time-consuming and is not feasible in busy nuclear medicine laboratories. Recently, the use of a nicotinic acid derivative, acipimox, has been suggested, but limited data are available on the image quality of the (18)F-FDG studies using this approach.


METHODS
We evaluated the feasibility and image quality of (18)F-FDG SPECT (with dual-isotope simultaneous acquisition (DISA) using (99m)Tc-tetrofosmin to assess perfusion) after acipimox administration in 50 nondiabetic patients. The image quality of both (18)F-FDG and (99m)Tc-tetrofosmin was assessed visually and quantitatively using myocardium-to-blood-pool (M/B) ratios as a measure of target-to-background ratio. The image quality and diagnostic value of DISA (99m)Tc-tetrofosmin SPECT was compared with standard (99m)Tc-tetrofosmin SPECT at baseline.


RESULTS
After acipimox administration, the plasma levels of free fatty acids were extremely low (68 +/- 89 nmol/L). No severe side effects were observed, only paroxysmal flushing. The (18)F-FDG image quality was good in 46 patients (92%) and moderate but still interpretable in the other 4 patients (8%). The clinical information of the baseline (99m)Tc-tetrofosmin SPECT was retained in the DISA (99m)Tc-tetrofosmin SPECT images because we did observe no substantial fill-in of perfusion defects by high (18)F-FDG uptake in the same segment.


CONCLUSIONS
Cardiac (18)F-FDG SPECT after acipimox is safe and resulted consistently in good image quality; this simple approach may be the method of choice for routine cardiac metabolic imaging.
Kam
Boen L R
BL
Department of Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands.
Valkema
Roelf
R
Poldermans
Don
D
Bax
Jeroen J
JJ
Reijs
Ambroos E M
AE
Rambaldi
Riccardo
R
Boersma
Eric
E
Rietveld
Trinet
T
Roelandt
Jos R T C
JR
Krenning
Eric P
EP
D000284:Administration, Oral; D002908:Chronic Disease; D003324:Coronary Artery Disease / Q000150:complications / Q000000981:diagnostic imaging*; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D019788:Fluorodeoxyglucose F18; D006321:Heart / Q000187:drug effects / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011719:Pyrazines / Q000008:administration & dosage; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging*
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011719:Pyrazines; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C078700:technetium tc-99m tetrofosmin; C027696:acipimox