Synthesis of [18F]fluoroalanine and [18F]fluorotamoxifen for imaging breast tumors.
To develop ligands for imaging breast tumors, [18F]fluoro analogue of tamoxifen and [18F]fluoroalanine were radiosynthesized. In vivo biodistribution studies were performed in mammary tumor-bearing rats. In studies on the biodistribution of an [18F]fluoro analogue of tamoxifen, tumor uptake decreased when rats were pretreated with diethylstilbestrol (DES), suggesting that tracer uptake in tumors was receptor-mediated. An estrogen receptor assay indicated that tumors have a receptor density of 7.5 fmol/mg protein. Studies of the distribution of [18F]fluoroalanine in tissue showed that the tumor-to-tissue ratio increases as a function of time. Positron emission tomography (PET) images of tumor-bearing rats demonstrated that tumors can be visualized 1 h after rats are injected with an [18F]fluoro analogue of tamoxifen. PET imaging of pigs after injection of 10 mCi of [18F]fluoro analogue of tamoxifen showed uterine uptake that could be blocked by DES (50 mg). The findings suggest that both radiotracers are useful for imaging breast tumors.
Yang
D
D
Division of Diagnostic Imaging, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Kuang
L R
LR
Cherif
A
A
Tansey
W
W
Li
C
C
Lin
W J
WJ
Liu
C W
CW
Kim
E E
EE
Wallace
S
S
D000409:Alanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D000818:Animals; D017690:Cell Transplantation; D004054:Diethylstilbestrol / Q000494:pharmacology; D005260:Female; D005462:Fluorine Radioisotopes; D009682:Magnetic Resonance Spectroscopy; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging*; D010053:Ovary / Q000000981:diagnostic imaging; D051381:Rats; D011916:Rats, Inbred F344; D011960:Receptors, Estrogen / Q000378:metabolism; D013552:Swine; D013629:Tamoxifen / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed; D014407:Tumor Cells, Cultured; D014599:Uterus / Q000000981:diagnostic imaging
D005462:Fluorine Radioisotopes; D011960:Receptors, Estrogen; D013629:Tamoxifen; C007742:3-fluoroalanine; D004054:Diethylstilbestrol; C037726:4-fluorotamoxifen; D000409:Alanine