Reproducibility of static and dynamic (18)F-FDG, (18)F-FLT, and (18)F-FMISO MicroPET studies in a murine model of HER2+ breast cancer.
OBJECTIVE
The objective of this study is to determine the reproducibility of static 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG), 3'-deoxy-3'-[(18)F]fluorothymidine ((18)F-FLT), and [(18)F]-fluoromisonidazole ((18)F-FMISO) microPET measurements, as well as kinetic parameters returned from analyses of dynamic (18)F-FLT and (18)F-FMISO data.


METHODS
HER2+ xenografts were established in nude mice. Dynamic data were acquired for 60 min, followed by a repeat injection and second scan 6 h later. Reproducibility was assessed for the percent-injected dose per gram (%ID/g) for each radiotracer, and with kinetic parameters (K                   (1)                   -k                   (4)                   , K                   (                     i                   )) for (18)F-FLT and (18)F-FMISO.


RESULTS
The value needed to reflect a change in tumor physiology is given by the 95 % confidence interval (CI), which is ±14, ±5, and ±6 % for (18)F-FDG (n = 12), (18)F-FLT (n = 11), and (18)F-FMISO (n = 11) %ID/g, respectively. V                   (                     d                   ) (=K                   (1)                   /k                   (2)), k                   (3), and K                   (FLT) are the most reproducible (18)F-FLT (n = 9) kinetic parameters, with 95 % CIs of ±18, ±10, and ±18 %, respectively. V                   (                     d                   ) and K                   (FMISO) are the most reproducible (18)F-FMISO kinetic parameters (n = 7) with 95 % CIs of ±16 and ±14 %, respectively.


CONCLUSIONS
Percent-injected dose per gram measurements are reproducible and appropriate for detecting treatment-induced changes. Kinetic parameters have larger threshold values, but are potentially sufficiently reproducible to detect treatment response.
Institute of Imaging Science, Vanderbilt University Medical Center, 1161 21st Ave. South, MCN AA-1105, Nashville, TN 37232-2675, USA.
Jennifer G
JG
Whisenant
Todd E
TE
Peterson
Jacob U
JU
Fluckiger
Mohammed Noor
MN
Tantawy
Gregory D
GD
Ayers
Thomas E
TE
Yankeelov
D000818:Animals; D015224:Dideoxynucleosides; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007700:Kinetics; D008325:Mammary Neoplasms, Experimental / Q000000981:diagnostic imaging* / Q000201:enzymology*; D051379:Mice; D008819:Mice, Nude; D008920:Misonidazole / Q000031:analogs & derivatives*; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods / Q000592:standards; D019275:Radiopharmaceuticals; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D015203:Reproducibility of Results
D015224:Dideoxynucleosides; D019788:Fluorodeoxyglucose F18; D008920:Misonidazole; D019275:Radiopharmaceuticals; D018719:Erb-b2 Receptor Tyrosine Kinases; C031843:fluoromisonidazole; C002854:alovudine