TABLE 2

Comparison of Rate of Internalization of 99mTc- and 111In-Labeled Peptides in AR4-2J Tumor Cells

PeptideTime point
30 min1 h2 h4 h
[111In-DTPA]-OC0.1 ± 0.3*†0.2 ± 0.3*†1.1 ± 1.2*†3.0 ± 0.4*†
[99mTc/EDDA/HYNIC]-OC (99mTc-(1))0.3 ± 0.7*†0.6 ± 0.3*†0.4 ± 0.3*†2.4 ± 0.8*†
[111In-DOTA]-TOC‡2.0 ± 0.7†§11.6 ± 0.8†
[99mTc/EDDA/HYNIC]-TOC (99mTc-(2))1.9 ± 1.1†§2.5 ± 2.5†§4.1 ± 0.8†§9.9 ± 0.6†§
[111In-DOTA]-TATE6.5 ± 0.6*§9.9 ± 1.2*§15.4 ± 1.9*§21.0 ± 2.3*§
[99mTc/EDDA/HYNIC]-TATE (99mTc-(3))6.0 ± 0.6*§9.5 ± 1.5*§12.0 ± 0.9*§18.8 ± 2.7*§
ANOVA test per time pointP = 3 · 10−4P = 3 · 10−4P = 1 · 10−4P = 1 · 10−4

  • ↵* P < 0.05 vs. [99mTc/EDDA/HYNIC]-TOC.

  • ↵† P < 0.05 vs. [99mTc/EDDA/HYNIC]-TATE.

  • ↵‡ Values from Ginj et al. (37).

  • ↵§ P < 0.05 vs. [111In-DTPA]-OC.

  • Values and SDs are the result of 2 independent experiments with triplicates in each experiment and are expressed as specific internalization (% added radioactivity/106 cells ± SD). Significance was analyzed by Kruskal–Wallis ANOVA test (analysis of variance of groups) for every time point (if >2 compounds) or Student t test (for 2 compounds).