PGP and neoplasm: 10–15 days after KB-3-1 and KB-V-1 tumor cell implantation the quantitative image analysis showed notable differences between the 11C-methionine uptake of the treated Pgp+ (SUVmean = 0.49 ± 0.03 and SUVmax = 0.84 ± 0.02) and untreated Pgp+ (SUVmean = 1.52 ± 0.43 and SUVmax = 2.43 ± 0.68) tumors and also between the treated Pgp− (SUVmean = 0.49 ± 0.03 and SUVmax = 0.76 ± 0.05) and untreated Pgp− (SUVmean = 1.48 ± 0.46 and SUVmax = 2.55 ± 1.0) tumors.