Table 1.

Ex vivo time-dependent biodistribution of [²²⁵Ac]Ac-DOTA-2Rs15d co-infused with 150 mg/kg Gelofusine in a subcutaneous HER2^pos mouse tumor model (n = 3).

										Dosimetry
										Absorbed	Absorbed
Ex vivo biodistribution										Dose	Dose × RBE factor (5)
Tissue/organ	1 h	3 h	6 h	24 h	48 h	72 h	96 h	120 h	168 h	(mGy/kBq)	(mGy/kBq)
Liver	0.66 ± 0.02	0.81 ± 0.19	0.32 ± 0.09	0.79 ± 0.08	0.63 ± 0.01	0.52 ± 0.13	0.40 ± 0.11	0.44 ± 0.04	0.41 ± 0.18	13.56	67.80
Spleen	0.25 ± 0.14	0.33 ± 0.02	0.17 ± 0.14	0.41 ± 0.07	0.23 ± 0.07	0.15 ± 0.06	0.16 ± 0.02	0.12 ± 0.01	0.15 ± 0.01	5.10	25.50
Lungs	0.15 ± 0.05	0.09 ± 0.01	0.05 ± 0.03	0.06 ± 0.02	0.07 ± 0.01	0.03 ± 0.03	0.02 ± 0.01	0.03 ± 0.01	0.04 ± 0.01	1.08	5.40
Heart	0.10 ± 0.02	0.06 ± 0.02	0.05 ± 0.01	0.10 ± 0.04	0.06 ± 0.04	0.05 ± 0.04	0.05 ± 0.05	0.06 ± 0.05	0.06 ± 0.03	1.59	7.95
Stomach	0.14 ± 0.03	0.11 ± 1.07	0.04 ± 0.00	0.05 ± 0.03	0.04 ± 0.02	0.03 ± 0.00	0.03 ± 0.01	0.02 ± 0.01	0.04 ± 0.01	0.97	4.85
Kidneys	8.98 ± 3.30	11.69 ± 1.1	10.31 ± 0.6	6.08 ± 0.27	4.13 ± 0.20	2.80 ± 0.71	1.93 ± 0.13	3.35 ± 1.03	1.91 ± 1.15	103.50	517.50
Lg. Int.	0.05 ± 0.03	0.08 ± 0.01	0.04 ± 0.00	0.05 ± 0.01	0.04 ± 0.01	0.01 ± 0.01	0.01 ± 0.01	0.02 ± 0.01	0.02 ± 0.00	0.62	3.10
Sm. Int.	0.07 ± 0.01	0.05 ± 0.00	0.04 ± 0.01	0.03 ± 0.00	0.01 ± 0.02	0.02 ± 0.01	0.01 ± 0.02	0.01 ± 0.00	0.01 ± 0.01	0.44	2.20
Pancreas	0.04 ± 0.02	0.03 ± 0.00	0.08 ± 0.11	0.03 ± 0.02	0.02 ± 0.00	0.02 ± 0.00	0.01 ± 0.01	0.01 ± 0.00	0.02 ± 0.00	0.57	2.85
Muscle	0.08 ± 0.03	0.03 ± 0.01	0.04 ± 0.01	0.02 ± 0.02	0.01 ± 0.01	0.02 ± 0.01	0.02 ± 0.00	0.03 ± 0.01	0.04 ± 0.02	0.64	3.20
Blood	0.23 ± 0.20	0.01 ± 0.01	0.01 ± 0.00	0.14 ± 0.21	0.13 ± 0.23	0.05 ± 0.08	0.23 ± 0.36	0.07 ± 0.04	0.18 ± 0.00	2.55	12.75
Bone	0.29 ± 0.06	0.10 ± 0.01	0.09 ± 0.04	0.36 ± 0.06	0.32 ± 0.10	0.06 ± 0.02	0.06 ± 0.01	0.05 ± 0.06	0.08 ± 0.03	3.62	18.10
Tumor	8.36 ± 0.23	9.64 ± 1.69	9.87 ± 1.38	6.58 ± 1.78	6.20 ± 1.00	4.24 ± 0.68	3.73 ± 0.58	1.70 ± 0.64	2.24 ± 1.00	115.58	577.90
T-to-Liver	12.62 ± 0.73	12.08 ± 1.71	33.40 ± 12.13	8.29 ± 1.59	9.79 ± 1.61	8.31 ± 1.10	9.60 ± 1.23	3.78 ± 1.06	5.60 ± 0.66	—	—
T-to-Kidneys	1.03 ± 0.42	0.82 ± 0.13	0.95 ± 0.08	1.08 ± 0.30	1.50 ± 0.22	1.55 ± 0.24	1.92 ± 0.18	0.60 ± 0.46	1.54 ± 1.32	—	—

Note: Results are presented as mean % IA/g ± SD. Dosimetry data are expressed as mGy/kBq.