Table 2.

Characteristics of selected longer-lived β⁺-emitting radionuclides for radioimmunoimaging.

Radionuclide	Half-life	Recommended timeframe	Availability	RIT radioisotope counterpart	Residualizing?	Possible accumulation sitesa	Current applicationb	Human studiesc	References
52Mn	134.2 h	1–2 weeks	Cyclotron or reactor	N/A	Residualizing	Brain, liver, kidney, pancreas	N/A	No	16 – 20
55Co	17.5 h	~ 48 hours	Cyclotron	N/A	Residualizing	Liver, kidney, bone	Brain ischemia and infarction	Yes	21 – 27
64Cu	12.7 h	~ 48 hours	Cyclotron or reactor, commercially available	67Cu	Residualizing	Liver, blood, spleen, lung, kidney	Cancer radiodiagnosis, RIT planning, treatment planning and monitoring	Yes (immuno -PET)	28 – 44
66Ga	9.4 h	~ 36 hours	Cyclotron	66Ga	Residualizing	Bone, liver, kidney, intestine	Radiodiagnosis, RIT planning	Yes	45 – 50
72As	25.9 h	~ 72 hours	Cyclotron	77As	Residualizing	Bone, blood cells	N/A	Yesd	51 – 55
76Br	16.2 h	~ 48 hours	Cyclotron, commercially available	76Br, 131I	Non- residualizing	Blood	Radiodiagnosis, RIT planning, brain edema	Yes	56 – 70
86Y	14.7 h	~ 48 hours	Cyclotron or heavy-ion accelerator, limited commercial supplye	90Y, 177Lu	Residualizing	Bone, blood, liver	RIT planning and monitoring	Yes	71 – 78
89Zr	78.4 h	~ 1 week	Cyclotron or reactor, limited commercial supply	90Y, 177Lu	Residualizing	Bone, liver, spleen, kidney	Radioimmunodiagnosis, RIT planning, treatment planning and monitoring	Yes (immuno -PET)	79 – 90
124I	100.2 h	~ 1 week	Cyclotron, commercially available	131I, 186Re, 188Re	Non- residualizing	Thyroid gland	Pharmacodynamics, Preoperative identification, dosimetry	Yes (immuno -PET)	91 – 108

^aPossible accumulation sites refer to the preferable sites for free isotopes.

^bCurrent application refers to current studies in both animals and humans.

^cHuman studies include all the radionuclide-involved clinical studies not limited to radiolabeled antibodies.

^d72As was used in humans to study environmental toxicity associated with high doses of natural arsenic [9].

^eLimited commercial supply indicates that the radioisotope is limited to a small number of production sites (<5).