Fig. 4. A loading dose of unlabeled antibody significantly reduced heterogeneity of antibody distribution in tumors, which can be captured by microscopic imaging but not macroscopic imaging.

a Schematic workflow of reconstructing the whole-tumor fluorescence distribution and measuring antibody delivery by macroscopic imaging. b–e The tumor uptake as measured by the MFI, and the tumor antibody distribution quantified by IQR,entropy, and uniformity from macroscopic imaging showed no significant difference between the two dosing groups. b–e Tissue specimens were available in n = 12 patients in the LD group and n = 12 in the non-LD group. f Schematic workflow of measuring antibody delivery in tissue histological sections and tumor microenvironmental factors using microscopic imaging. g–j The tumor uptake measured by the MFI from microscopic imaging also showed no difference between the two groups, but the antibody distribution measured by IQR, entropy, and uniformity from microscopic imaging showed significantly higher heterogeneity in the non-LD group (*p < 0.05, ns: p > 0.05). p value = 0.030 h, 0.036 i, 0.025 j. k–n Vessel area fraction, EGFR area fraction, αSMA area fraction, and tumor size were not statistically different between the LD and the non-LD group. (Scale bar in a and f: 2 cm; graphs plotted mean with standard deviation). g–n Tissue specimens were available in n = 12 patients in LD group and n = 10 in the non-LD group. Mann–Whitney U test (two-tailed) was used in b–e, g–n.