A comparative PET imaging study with the reversible and irreversible EGFR tyrosine kinase inhibitors [11C]erlotinib and [18F]afatinib in lung cancer-bearing mice

EJNMMI Research

Table 1 Summary of tumor-to-background ratios

Cell line	Number	Tumor-to-background [ ¹¹ C]erlotinib	Number	Tumor-to-background [ ¹⁸ F]afatinib
Unblocked
A549	1	1.0 ± 0.3	4	1.5 ± 0.3*
H1975	2	0.9 ± 0.3	5	0.8 ± 0.2
HCC827	3	1.9 ± 0.5*	6	2.3 ± 0.4*
Tariquidar blocked (15 mg/kg)
A549	7	1.2 ± 0.3	10	1.3 ± 0.3*
H1975	8	1.0 ± 0.2	11	0.8 ± 0.2
HCC827	9	1.8 ± 0.3*	12	1.9 ± 0.4*

Comparison of tumor-to-background ratios in non-blocked (1 to 6) and blocked situation (7 to 12) ratios determined in the last frame of the scans (60 to 90 min for [¹¹C]erlotinib and 90 to 120 min for [¹⁸F]afatinib) and averaged over three animals. P-gp blocking was performed with 15 mg/kg tariquidar. *Tumor-to-background is statistically significant (P < 0.05, Student’s t-test for paired data). Mutations: A549 (wild type), H1975 (L858R/T790M), and HCC827 (exon 19 deletion).