Decreased defluorination using the novel beta-cell imaging agent [18F]FE-DTBZ-d4 in pigs examined by PET

EJNMMI Research

Table 3 Defluorination rate in piglets between the deuterated and non-deuterated FE-DTBZ analogues (p < 0.05)

Parameter	Unit	Exp 1	Exp 2	Exp 3		Average	SEM
[¹⁸F]FE-DTBZ
k _{defluorination} ^a	1/min	0.015	0.0079	0.01214		0.012	0.002
t _1/2	min	46.2	87.7	57.1		63.4
RSS		0.34	1.03	0.65
[¹⁸F]FE-DTBZ-d4
k _{defluorination} ^a	1/min	0.0016	0.00042	0.0035	0.00088	0.0016	0.0007
t _1/2	min	438.7	1650.4	197.5	787.7	433.9
RSS		0.50	0.14	0.16	0.16

^aThe rate constant k _{defluorination} was almost 7.5 times lower after deuteration (0.0016 ± 0.0007 min^-1 vs. 0.012 ± 0.002 min^-1), resulting in an increased stability half-life (more than 6 h, up from 1 h). t _1/2, half-life; RSS, regression sum of squares; SEM, standard error of the mean.