Figure 3.

Increase in [¹¹¹In]In-Man(6)-Alb-FL signal directly correlates with the metastatic burden in the lung. (A) Schematic showing SPECT/CT imaging of lung metastases in mice after intravenous injection of different numbers of 4T1 cancer cells (low met vs high met). (B,C) Different metastatic burdens induced by intravenous injection of low (5 × 10⁴) or high (1 × 10⁵) number of 4T1 cells were confirmed using H&E staining (B) and determining the lesion area of lung metastatic foci and number of lung metastases (C) 14 days after tumor injection. Scale bar = 100 μm. (D) Representative SPECT/CT images (coronal, sagittal, and transverse views) of mice with lower metastases and higher metastases 24 h after [¹¹¹In]In-Man(6)-Alb-FL injection. [¹¹¹In]In-Man(6)-Alb-FL was able to detect lung metastases (LM) with significantly higher signal in lungs from the high met group than in those from the low met group. (E) Ex vivo biodistribution of [¹¹¹In]In-Man(6)-Alb-FL in various organs of mice with lung metastases, expressed as % ID/g. (F) Correlation between [¹¹¹In]In-Man(6)-Alb-FL signal and metastatic burden, as determined by the number of metastatic foci in lungs from 4T1-bearing mice after intravenous tumor injection. n = 3–4 mice/group. Data represent the mean ± SEM. *P < 0.05, **P < 0.01 using Student’s t test.