Radiotracers Used for the Scintigraphic Detection of Infection and Inflammation

Table 4

Characteristics of selected radiotracers.

Radiotracer molecules			Dose formulation	Radiolabeling		Radiotracer purification method
Isotope	Isotope chelator	Cold moiety		Conditions	Efficiency
Synthetics
^111In	DTPA	fMLFK	Sephadex G-10 eluent	RT/30 min	95%	RP-HPLC
^99mTc	HYNIC	fMLFK	Sodium phosphate, saline, pH 8	RT/30–60 min	>96%	RP-HPLC
^99mTc	HYNIC	MLF-OMe	Sodium phosphate, saline, pH 8	RT/30–60 min	>96%	RP-HPLC
^68Ga	None	Citrate	Sodium citrate, pH 6-7	90°C/10 min	>98%	Anion exchange column
^68Ga	None	TAFC	1.1 M sodium acetate, pH 6-7	RT/15 min	≥95%	—
^68Ga	None	FOXE	1.1 M sodium acetate, pH 6-7	80°C/20 min	≥95%	—
^111In	DTPA	LTB-4; (DPC11870-11)	Ammonium acetate, pH 5.5	RT/30 min	95%	RP-HPLC
^99mTc	HYNIC	LTB-4 (MB88)	Tricine, isonicotinic acid, PBS, SnSO4, pH 7	100°C/30 min	95%	RP-HPLC
^18F	pFBA	LTB-4 (MB67)	Sodium acetate, PBS, pH 4–7	50°C/>30 min	65–85%	Evaporation, & N2↑
Antibiotics
^99mTc	None	Fluconazole	PYP, SnCl2, KBH4 in 0.1 M NaOH, saline, PBS, pH 7.5	RT/120 min	90%	—
^99mTc	None	Ciprofloxacin	Sn(II) tartrate	RT/15 min	>40%	—
^99mTc	None	Enrofloxacin	Ethanol : water [1 : 1]	60°C/10 min	81%	SepPak tC2 cartridge
^99mTc	None	Pefloxacin	SnCl2, pH 6	100°C/30 min	98%	—
^99mTc	None	Ceftizoxime	Sodium dithionite, N2↑	100°C/5 min	>90%	—
^99mTc	None	Vancomycin	SnCl2, pH 6-7	RT/10 min	99%	—
^99mTc	None	Kanamycin	SnCl2, pH 6-7	RT/25–30 min	99%	—
^99mTc	None	Alafosfalin	SnCl2, pH 6	RT/5–10 min	90–95%	—
^99mTc	None	Phosphomycin	SnCl2, pH 7	RT/<1 min	98%	—
^99mTc	None	Cefoperazone	SnCl2, pH 8	RT/10 min	98%	—
^99mTc	None	Cefuroxime axetil	SnCl2, pH 5	RT/15 min	92%	—
^99mTc	[^99mTc(CO)5]	Novobiocin	Water	RT/30 min	99%	—
Biological origin
Cells:
^18FDG	None	Leukocytes	Autologous LEuk, saline	37°C/30 min	79% ^18F-gran.	Centrifugation
^111In	Oxine	Dendritic cells	Allogeneic DC, saline	RT/60 min	94%	Centrifugation
^111In	Oxine	Lymphocytes	Autologous LYM, lym poor plasma	37°C/10 min	77%	Centrifugation
Macromolecules
^111In	DTPA	hpc-IgG	Citrate	RT/instant	>95%	Centrifugation
^99mTc	None	hpc-IgG	Tartrate, SnCl2	RT/20 min	90%	—
^99mTc	HYNIC	hpc-IgG	Acetate, tricine, SnSO4	RT/15 min	>95%	—
^99mTc	None	Rat pc-IgG	MDP, SnCl2, PBS, N2	RT/20 min	≥94%	—
^99mTc	None	HSA	Saline, SnCl2, N2, pH 2–7	RT/20 min	≥95%	—
^99mTc	None	Infliximab	MDP, SnCl2, PBS, N2	RT/20 min	≥91%	—
^99mTc	None	Fanolesomab	Maltose, tartrate, succinic acid, Sn(II) tartrate, glycine, EDTA, ascorbic acid, pH 6	37°C/30 min	≥90%	—
^99mTc	HYNIC	E-selectin peptide; (IMP-178)	2-OH--cyclodextrin, Sncl2, acetate, ascorbate	RT/10 min; 100°C/15 min	92%	—
^123I	None	B2702-p; (75–84)	PBS, pH 7	RT/15 min	>80%	Anion exchange column
^99mTc	[^99mTc(CO)5]	B2702-p; (+his-gly)	PBS, pH 7	100°C/15 min then 80°C/20 min	>90%	—
^99mTc	HMPAO	PEG-liposomes	5% glucose	RT/15 min	70–80%	Size exclusion on PD-10 column
^123I	None	hr-IL-1	0.5% BSA in PBS	RT/10 min	50–80%	Sephadex G-25 column/0.2 m filter
^123I	None	hr-IL-1	0.25% gelatine in PBS	RT/10 min; ice/30 min	25–35%	Sephadex G-25 column/0.2 m filter
^18F	[para-^18F-fluoroethyl]	hr-IL-1ra	PBS	38°C/45 min	7–24%	HiTrap column/filter
^99mTc	None	IL-18bp-Fc-IL-1ra	PBS, pH 7	RT/30 min	>75%	Sephadex G-25 column
^99mTc	HYNIC	hr-IL-2	SnCl2, tricine, nicotinic acid, pH 6-7	RT/<60 min	>99%	—
^123I	None	hr-IL-2	5% glucose	RT/30 min	>96%	HPLC; 30°C/20 min/N2
^18F	pFBA	hr-IL-2	Saline, <10% ethanol	borate pH 8.5 : EtOH [1 : 1], 50°C/10 min	25–35%	RP-HPLC
^99mTc	HYNIC	hr-IL-8	SnSO4, tricine, nicotinic acid, 0.5% BSA in PBS, pH 7	70°C/30 min	>98%	—
^99mTc	HYNIC	hr-IL-12	Stannous tartrate, tricine, pH 6-7	RT/30 min	75–85%	G-50 microspin column
^99mTc	HYNIC	C5a	SnSO4, tricine, 0.5% BSA in PBS	RT/30 min	>95%	Sephadex G-25 column/0.2 m filter
^99mTc		C5adR
Smaller fragments:
^99mTc	None	UBI-29-41	Sn(II) PYP, potassium borohydride, NaOH, pH 5-6	RT/60 min	95%	—
^99mTc	HYNIC	UBI-29-41	SnCl2, tricine, mannitol, pH 4	RT/>60 min	>96%	—

RT: room temperature; RP: reverse phase; HPLC: high pressure liquid chromatography; none: isotope is directly bound to the structure of the nonradioactive component; pFBA: para-¹⁸F-fluorobenzaldehydel; : heat; PBS: phosphate buffered saline; UBI: ubiquicidin; hpc: human polyclonal; IL: interleukin; hr: human recombinant; LT: leukotriene; DC: dendritic cells; LEuk: Leukocytes; LYM: Lymphocytes.