Table 4.

Tracer uptake of F-18 labeled tryptophan derivative tracers in various tumor models.

Tracer	Tumor model (all in mice subcutaneous xenografts unless otherwise indicated)	Tracer uptake in xenografts
		Absolute values	Tumor/background ratios
5-[18F]FEHTrp
Li, et al. 2010a	S180 (fibrosarcoma)	5.19±0.79	tumor/muscle ratio: 2.79 tumor/blood ratio: 2.87
	Intramuscular inflammation	1.82±0.28	inflammation/muscle ratio: 0.94 inflammation/blood ratio: 0.91
Krämer, et al. 2012b#	NCI-H69 (SCLC)	~1.6	tumor/reference ratio: ~1.9
	PC-3 (prostate)	~1.5	tumor/reference ratio: ~1.8
	MDA-MB-231 (breast)	~1.3	tumor/reference ratio: ~1.3
He, et al. 2013c#	S180, Hepa1-6 cell	N/A	tumor/muscle ratio: 2.51±0.14 tumor/inflammation ratio: 1.53±0.09
	Subcutaneous inflammation	N/A	inflammation/muscle ratio: ~2.0 inflammation/blood ratio: ~1.0
4/6/7-[18F]FEHTrp
Chiotellis, et al. 2014d#	NCI-H69	~0.7 (4-[18F]FEHTrp); ~0.9 (6-[18F]FEHTrp); ~1.1 (7-[18F]FEHTrp)	tumor/muscle: 2.6±0.2*
2-[18F]FPTrp
Chiotellis, et al. 2013e	NCI-H69	N/A	tumor/reference region ratio: 2.38±0.02
	PC-3	N/A	tumor/reference region ratio: 2.4
5-[18F]FPTrp
Chiotellis, et al. 2013e	NCI-H69	N/A	tumor/reference region ratio: 1.8
	PC-3	N/A	tumor/reference region ratio: 1.8
5-OH-2-[18F]FPTrp
Chiotellis, et al. 2016d#	NCI-H69	~0.6	tumor/muscle ratios: 4.3±0.9
	PC-3	~0.5	tumor/muscle ratios: 4.2±0.6
	C6 (glioma)	~0.4	tumor/muscle ratios: 2.7±0.3
5-OH-2-[18F]FETrp
Chiotellis, et al. 2016d#	NCI-H69	~0.6	tumor/muscle ratios: 3.9±0.2
	PC-3	~0.5	tumor/muscle ratios: 4.2±0.4
	C6	~0.4	tumor/muscle ratios: 3.2±1.1
[18F]FPOTrp
He, et al. 2013c#	S180, Hepal-6 (hepatocellular carcinoma)	N/A	tumor/muscle ratio: 3.1±0.11 tumor/inflammation ratio: 2.53±0.06
	Subcutaneous inflammation	N/A	inflammation/muscle ratio: −1.3 inflammation/blood ratio: −0.5
Shih, et al. 2014#	NCI-H187Lu (SCLC)	high uptake at 45 min p. i.
	PC-3	low uptake (<2 %ID/g) at 22 min p. i.
5[18F]FTrp
Tang, et al. 2017#	17095A, 17082A (NSCLC)	high uptake (~4 %ID/g) at 20 min p. i.
	CT26 (colon)	high uptake (5-8 %ID/g) at 20 min p.i.
4/5/6/7[18F]FTrp
Zlatopolskiy, et al. 2018#	MCF-7 (ER negative breast), PC-3, NCI-H69 xenograft in chicken embryos	high uptake in all tumor xenograft at 30 min p.i., but no values shown
5[18F]F-AMT
Giglio, et al. 2017#	B16F10 cell (skin melanoma)	high uptake in tumor xenograft, but no values shown
1-[18F]FETrp
Xin, et al. 2017f	MDA-MB-231	4.6±0.4 (L-isomer) 1.0±0.2 (D-isomer)	N/A
Michelhaugh, et al. 2017g	glioblastoma	1.17±0.28	N/A
	breast cancer metastasis	0.70±0.10	N/A
	NSCLC metastasis	0.51±0.05	N/A
Xin, et al. 2019f	PC-3	7.5±0.6 6.4±1.0h	tumor/muscle ratio: 4.3 tumor/muscle ratio: 4.9h
	H2009 and H460 (NSCLC)	5.3±0.8 (H2009); 9.0±1.4 (H460)	N/A
	orthotopic A549 (lung)	4.5±0.5	tumor/normal lung ratio: 2.6
	intracranial 73 C (glioma)	4.1±0.7	tumor/brain ratio: 2.9

^a:%ID/g uptake at 60 min p.i.;

^b:SUV at 30-45 min p.i.;

^c:%ID/g ratio at 30-60 min p.i.;

^d:SUV and SUV ratio at 60-75 min p.i.;

^e:xenograft to reference SUV ratio at 60 min p.i;

^f:%ID/g at 120 min p.i.;

^g:patient-derived xenografts, SUV at 30-60 min p.i.;

^h:%ID/g at 240 min p.i.

^#:uptake based on the text or figures/graphs presented in the paper (values after ~ sign are estimates);

^*:all tracers accumulated in the tumor xenograft, values for 6-[¹⁸F]FEHTrp are shown – uptake of other two tracers ranged from 1.9 to 2.1.

Abbreviations: [¹⁸F]FEHTrp: (2-[¹⁸F]fluoroethoxy)-tryptophan; [¹⁸F]FPTrp: (3-[¹⁸F]fhioropropyl)-tryptophan; [¹⁸F]FETrp: (2-[¹⁸F]fluoroethyl)-tryptophan; [¹⁸F]FPOTrp: (3-[¹⁸F]fluoropropyloxy)-tryptophan; [¹⁸F]FTrp: [¹⁸F]fluorotryptophan; [¹⁸F]F-AMT: [¹⁸F]fluoro-α-methyl-tryptophan; SCLC: small cell lung cancer; NSCLC: non-small cell lung cancer; ER: estrogen receptor; N/A: not available; %ID/g: percent injected dose/gram; p.i.: post injection; SUV: standard uptake value.