Table 2.

List of example carrier molecules derived from studies of radiopharmaceuticals

Class of carrier	Example carrier molecule	Example of disease or target	Biological WB and/or blood half-life	Normal tissues with uptake/involved in clearance	References
Antibodies	Ibritumomab	Non-Hodgkin lymphoma/CD20	Approx. 400 h (WB), 46 h (whole blood)	Spleen, liver, red marrow	[37, 38]
	Trastuzumab	Breast cancer/HER2	Approx. 400 h (WB), 11 and 176 h (blood; fast and slow)	Liver, kidneys	[39, 40]
Peptides	Somatostatin analogues	Neuroendocrine disease/somatostatin receptor	Approx. 1.3 and 71 h (WB; fast and slow), 1.6 and 59 h (blood; fast and slow)	Kidneys	[41]
	Prostate-specific membrane antigen (PSMA) targeting ligands	Metastatic castration-resistant prostate cancer/PSMA	Approx. 45–57 h (WB), 0.2 and 12 h (blood; fast and slow)	Lacrimal and salivary glands, kidneys	[42, 43]
Small molecules	Fluoro-2-deoxy-D-glucose (FDG)	Glucose metabolism	∞ or 12 min–1.5 h (WB), < 1 min, but also minor fraction with longer half-life (blood)	Kidneys and urinary tract, brain, heart	[44]
	(Fluoroethyl)-L-tyrosine (FET)	Amino acid metabolism	14 h (WB), < 0.05 h and 14 h (blood; fast and slow)	Liver, kidneys	[44]
	Fibroblast activation protein inhibitors	Tumour microenvironment	24–65 h (WB), 9 h (blood)	Kidneys and urinary tract	[45, 46]
	Meta-iodobenzylguanidine (mIBG)	Neuroendocrine disease/neurosecretory granules	9–130 h (blood)	Liver, adrenal glands, bone marrow	[47]
Non-targeted compounds	Microspheres for selective internal radiotherapy*	Disease in the liver	∞ (WB), N.A. (blood)	Local tissues	[20]

*Injected intra-arterially