Table 2.

Binding Affinity and Biodistribution Data for Radiolabeled αMSH Analogues for PET Imaging of Melanoma.^a

Tracer Name	Average Binding Affinity (IC50, nmol/L)	Tumor Model	Time Point (hour p.i.)	Average Organ Uptake, %ID/g				Uptake Ratio			Reference
				Tumor	Blood	Muscle	Kidney	Tumor- To-Blood	Tumor- To-Muscle	Tumor- To-Kidney
68Ga-DOTA-Pip-Nle- CycMSHhex	0.32	B16F10	2	21.9	0.2	0.1	5.5	96	211	4.0	60
68Ga-DOTA-PEG2-Nle- CycMSHhex	0.75	B16F10	1	8.0	0.5	0.1	5.1	16	70	1.6	60
68Ga-DOTA-PipPip-Nle- CycMSHhex	0.16	B16F10	1	6.5	0.5	0.1	6.2	14	53	1.1	60
68Ga-DOTA-Re(Arg11) CCMSH	N/A	B16F1	2	4.25	0.40	0.10	6.80	N/A	N/A	N/A	59
68Ga-CHX-A”-Re(Arg11) CCMSH	3.8	B16F1	2	2.68	0.58	0.28	7.39	4.6	9.6	N/A	55
64Cu-NOTA-GGNle- CycMSHhex	1.6	B16F1	4	12.71	0.30	0.36	3.53	42	35	3.6	61
64Cu-CBTE2A-Re(Arg11) CCMSH	5.4	B16F1	4	7.37	0.11	0.07	6.92	N/A	N/A	N/A	63
64Cu-DOTA-Re(Arg11) CCMSH	N/A	B16F1	4	7.35	0.65	0.32	9.75	11.4	22.8	N/A	62
64Cu-DOTA-GGNle- CycMSHhex	2.1	B16F1	4	5.25	0.81	0.02	7.45	6.5	263	0.7	61
64Cu-DOTA-NAPamide	3.66	B16F10	4	4.43	∼1.0	∼0.5	∼8.0	N/A	N/A	N/A	64
18F-FB-RMSH2	9.0	B16F10	2	1.36	0.40	0.21	17.8	3.5	7.0	N/A	66
18F-FP-RMSH-1	6.1	B16F10	4	1.09	0.15	0.06	4.41	7.5	17	N/A	65
18F-FB-RMSH1	5.7	B16F10	2	0.83	0.39	0.40	9.81	1.5	3.1	N/A	66
18F-FP-RMSH-2	33.7	B16F10	2	0.78	0.31	0.20	15.13	2.7	4.0	N/A	65
18F-FB-NAPamide	7.2	B16F10	4	0.25	0.07	0.04	0.53	3.6	7.5	N/A	67

Abbreviations: IC₅₀, half maximal inhibitory concentration; ID, injection dose; N/A, not applicable; p.i., post injection; αMSH denotes alpha-melanocyte-stimulating hormone.

^a Table is sorted by the average tumor uptake.