Mean SUVs of the tumor and normal brain uptake from small animal PET studies performed with (S)-[18F]14 in four mice, (S)-[18F]15 in three mice, and (S)-[18F]FET in three mice at early (5–15 min) and late (45–60 min) time points after injection. Errors bars show standard deviation. p values represent comparisons of tumor and brain uptakes at early and late time points for (S)-[18F]14, (S)-[18F]15, and (S)-[18F]FET through 1-way ANOVA with Tukey post-tests.*, p < 0.001 for 15 vs FET, p < 0.001 for 15 vs 14, **, p < 0.05 for 15 vs FET, p < 0.01 for 15 vs 14, †, p < 0.01 for FET vs 14, ‡, p < 0.001 for 15 vs FET and 15 vs 14, ‡‡, p < 0.01 for 15 vs FET, p < 0.001 for 15 vs 14, #, p < 0.001 for FET vs 14, ##, p < 0.01 for FET vs 14.