. Author manuscript; available in PMC: 2013 May 1.

Published in final edited form as: Drug Deliv Transl Res. 2012 Jan 19;2(1):22–30. doi: 10.1007/s13346-011-0052-0

Table 1.

Examples of prodrug enzyme and substrate combinations that are compatible with clinically translatable imaging technologies

Substrates	Enzymes	Imaging technology	Purpose
[¹⁸F] FEAU	TK	PET	Imaging
[¹⁸F]FHBG	TK	PET	Imaging
[¹²⁴I] FIAU/[¹³¹I]FIAU	TK	PET/SPECT	Imaging/therapy
5-FC	bCD/yCD	¹⁹F MRS/MRSI	Therapy
5-FU	UPRT	¹⁹F MRS/MRSI	Therapy
3,5-DFBGlu	CPG2	¹⁹F/¹³C MRSI	Imaging
L-[¹⁸F] FAC/L-[¹⁸F]FMAC	dCK	PET	Imaging

5-FC 5-fluorocytosine, 5-FU 5-fluorouracil, TK thymidine kinase, bCD bacterial cytosine deaminase, yCD yeast cytosine deaminase, UPRT uracil phosphoribosyltransferase, CPG2 carboxypeptidase G2, dCK deoxycytidine kinase, PET positron emission tomography, SPECT single-photon emission computed tomography, MRS magnetic resonance spectroscopy, MRSI magnetic resonance spectroscopic imaging