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.

<bold>Purpose: </bold>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.<bold>Procedures: </bold>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.<bold>Results: </bold>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.<bold>Conclusions: </bold>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. [ABSTRACT FROM AUTHOR]