Table 2.

Biodistribution data for ¹⁸F-FP-MSH-1 and 2 in C57BL/6 mice bearing subcutaneously xenotransplanted B16F10 murine melanoma and Foxn1 nude mice bearing A375M human melanoma. Data were expressed as mean ± SD, indicating the percentage administered activity (injected dose) per gram of tissue (%ID/g) after intravenous injection of 110- 130 μCi (4.01-4.87 MBq) tracers (n = 3)

Organ (%ID/g)	18F-FP-RMSH-1				18F-FP-RMSH-2
	B16F10			A 375M	B16F10	A 375M
	1h	2h	4h	2h	2h	2h
Tumor	1.80 ± 0.18	2.12 ± 1.08	1.09 ± 0.23	*0.84 ± 0.39	*0.78 ±0.10	*0.63 ± 0.19
Blood	0.90 ± 0.10	0.42 ± 0.06	0.15 ± 0.04	0.33 ± 0.22	0.31 ± 0.11	0.20 ± 0.09
Heart	0.55 ± 0.03	0.31 ± 0.06	0.14 ± 0.06	0.41 ± 0.19	0.21 ± 0.06	0.18 ± 0.07
Liver	1.36 ± 0.22	0.78 ± 0.05	0.44 ± 0.11	0.69 ± 0.21	*1.97 ± 0.17	1.66 ± 0.08
Lung	1.72 ± 0.16	0.80 ± 0.03	0.31 ± 0.07	0.68 ± 0.10	0.64 ± 0.15	0.47 ± 0.21
Muscle	0.33 ± 0.11	0.17 ± 0.03	0.06 ± 0.01	0.19 ± 0.08	0.20 ± 0.05	0.10 ± 0.02
Spleen	0.61 ± 0.05	0.34 ± 0.07	0.20 ± 0.04	0.34 ± 0.19	0.53 ± 0.03	0.27 ± 0.03
Brain	0.11 ± 0.04	0.11 ± 0.04	0.04 ± 0.01	0.05 ± 0.01	0.04 ± 0.01	0.04 ± 0.01
Intestine	0.99 ± 0.45	1.14 ± 0.80	0.29 ± 0.18	0.40 ± 0.19	0.91 ± 0.33	0.17 ± 0.00
Stomach	0.67 ± 0.31	0.47 ± 0.24	0.31 ± 0.07	0.44 ± 0.02	0.42 ± 0.14	0.52 ± 0.50
Pancreas	0.32 ± 0.08	0.18 ± 0.03	0.06 ± 0.01	0.78 ± 0.49	0.10 ± 0.03	0.09 ± 0.01
Bone	0.69 ± 0.18	0.68 ± 0.37	0.17 ± 0.09	0.23 ± 0.11	0.52 ± 0.08	0.25 ± 0.12
Kidney	8.82 ± 0.76	6.76 ± 0.82	4.41 ± 0.78	6.59 ± 1.53	*15.13 ± 0.88	*13.45 ± 0.91
Uptake Ratio
Tumor / Blood	2.03 ± 0.33	3.80 ± 0.89	7.45 ± 0.69	3.11 ± 1.30	2.74 ± 0.80	2.90 ± 0.04
Tumor / Muscle	5.78 ± 1.35	9.36 ± 3.98	16.97 ± 1.73	4.49 ± 0.17	3.98 ± 1.09	6.40 ± 2.66

^*P <0.05 when compared with ¹⁸F-FP-RMSH-1 at 2h