Autoradiography screening of potential positron emission tomography tracers for asymptomatic abdominal aortic aneurysms

Figures & data

Table I. The in vitro labelling conditions for the different tracers.

Abbreviation	Tracer	Molecular target	Concentration	Specific displacer	Buffer	Pre-incubation	Incubation	Wash (on ice)
CRPB	[^68Ga]CRP-binder	C-reactive protein	0.01 MBq/mL, 0.205 nM	Phosphocholine, 10 µM	Tris-HCl 0.05 M, pH 7.4 + BSA 0.2% + MgCl2 5 mM + bacitracin 50 mg/L	10 min RT	60 min, 37°C	3 × 3 min
DAA	[^11C]DAA1106	Translocator protein (18 kDa)	3 nM	PK11195, 1 µM	Tris-HCl 0.05 M, pH 7.4	–	40 min, RT	3 × 3 min
DDE	[^11C]D-deprenyl	Unknown target receptor	10 nM	D-deprenyl, 1 µM	PBS + BSA, 1%, pH 7.4	–	40 min, 37°C	3 × 3 min
DED	[^11C]-deuterium-L-deprenyl	Astrocytes	10 nM	L-deprenyl, 10 µM	10 min in PBS + BSA	10 min RT	40 min, 37°C	3 × 3 min
[^18F]fluciclatide	[^18F]fluciclatide	Integrin αvβ3	13 nM	Fluciclatide, 0.56 µM	Tris-HCl 0.05 M, pH 7.4	10 min RT	60 min, RT	3 × 3 min
TF2-IMP	[^68Ga]IMP461 and bi-specific antibody TF2 052107	Carcinoembryonic antigen	0.25 MBq/mL	No antibody	Tris-HCl 0.05 M, pH 7.4, + BSA 0.2% + MgCl2 5 mM + bacitracin 50 mg/L	60 min at 37°C with TF2, wash 2×2 min wash on ice	60 min, 37°C	2 × 3 min
FMTO	[^18F]F-metomidate	Mitochondrial cytochrome P-450 species in the adrenal cortex	0.007 MBq/mL	F-metomidate, 1 µM	Tris-HCl 0.05 M, pH 7.4	25 min, RT	40 min, RT	3 × 3 min
FVOZ	[^18F]vorozole	Aromatase	0.1 MBq/mL, 2 nM	Vorozole, 1 µM	Tris-HCl 0.05 M, pH 7.4	10 min, RT	30 min, RT	3 × 2 min

BSA = bovine serum albumin; HCl = hydrochloric acid; M = molar; MBq = megabecquerel; nM = nanomolar; PBS = phosphate-buffered saline; RT = room temperature; Tris = tris(hydroxymethyl)aminomethane; µM = micromolar.

Figure 1. Autoradiography with [¹⁸F]fluciclatide on AAA tissue from two patients. A: without additional blocking agent; and B: with additional blocking agent (unmarked fluciclatide).