Table 3

Biodistribution data of peptide targeting labeled with four different radionuclides in s.c. SK-RC-52 xenografted mice pretargeted with G250xDTIn1a

6 h p.i.24 h p.i.48 h p.i.72 h p.i.
111In-diDTPA
 Blood1.96 ± 0.220.16 ± 0.030.06 ± 0.000.04 ± 0.00
 Muscle0.23 ± 0.040.06 ± 0.020.05 ± 0.010.06 ± 0.01
 Tumor42.6 ± 7.3030.5 ± 15.025.3 ± 11.925.6 ± 7.71
 Lung1.09 ± 0.190.20 ± 0.020.16 ± 0.020.16 ± 0.02
 Spleen2.29 ± 2.120.54 ± 0.260.78 ± 0.250.83 ± 0.19
 Kidney1.81 ± 0.101.31 ± 0.041.00 ± 0.110.88 ± 0.07
 Liver3.64 ± 1.871.84 ± 0.852.35 ± 0.291.84 ± 0.44
 Intestine0.83 ± 0.500.29 ± 0.080.24 ± 0.080.19 ± 0.09
 T/B22.7 ± 2.0180 ± 64429 ± 209693 ± 218
131I-diDTPA
 Blood3.93 ± 1.320.58 ± 0.170.10 ± 0.030.04 ± 0.00
 Muscle0.55 ± 0.210.05 ± 0.020.01 ± 0.010.01 ± 0.00
 Tumor14.46 ± 4.913.30 ± 1.940.81 ± 0.310.33 ± 0.15
 Lung1.90 ± 0.680.33 ± 0.110.05 ± 0.010.03 ± 0.00
 Spleen1.67 ± 0.750.34 ± 0.150.07 ± 0.060.03 ± 0.01
 Kidney1.40 ± 0.400.26 ± 0.050.11 ± 0.010.10 ± 0.02
 Liver4.89 ± 1.871.07 ± 0.460.28 ± 0.240.10 ± 0.03
 Intestine0.80 ± 0.300.15 ± 0.040.03 ± 0.010.02 ± 0.00
 T/B3.69 ± 0.185.39 ± 2.428.54 ± 3.308.14 ± 3.84
188Re-diDTPA
 Blood2.94 ± 0.300.96 ± 0.260.78 ± 0.130.90 ± 0.22
 Muscle0.47 ± 0.140.82 ± 0.07N.D.bN.D.
 Tumor20.68 ± 2.727.43 ± 2.238.78 ± 4.088.01 ± 5.01
 Lung1.54 ± 0.471.76 ± 0.47N.D.N.D.
 Spleen2.23 ± 1.451.15 ± 0.17N.D.N.D.
 Kidney1.85 ± 0.131.00 ± 0.14N.D.N.D.
 Liver3.53 ± 0.842.11 ± 0.99N.D.N.D.
 Intestine0.84 ± 0.351.05 ± 0.68N.D.N.D.
 T/B7.05 ± 0.818.10 ± 2.8811.60 ± 5.688.89 ± 4.87
99mTc-diDTPA
 Blood3.96 ± 0.410.65 ± 0.17N.D.N.D.
 Muscle0.46 ± 0.120.09 ± 0.02N.D.N.D.
 Tumor24.60 ± 6.6410.43 ± 3.41N.D.N.D.
 Lung2.08 ± 0.300.41 ± 0.09N.D.N.D.
 Spleen2.33 ± 1.820.68 ± 0.16N.D.N.D.
 Kidney3.70 ± 0.221.80 ± 0.35N.D.N.D.
 Liver3.75 ± 1.023.13 ± 1.02N.D.N.D.
 Intestine0.86 ± 0.080.24 ± 0.06N.D.N.D.
 T/B6.27 ± 1.6916.61 ± 5.12N.D.N.D.
  • a Tumor-bearing mice were pretargeted with 0.1 nmol of bsMAb G250xDTIn1, followed by administration, 24 h later, of 3.8 pmol of the radiolabeled bivalent peptides: diDTPA-FKYK labeled with 111In or 131I or TscGC-diDTPA(In)-KYKK labeled with 188Re or 99mTc. Mice were killed 6 h p.i. of the radiolabel, and their biodistribution was obtained (5 mice/group). Uptake is expressed as %ID/g.

  • b N.D., not determined.