Inveon micropet microct rodent scanner

The Inveon microPET/microCT rodent scanner (Siemens Medical Solutions USA, Inc.) was used for imaging after mice were injected with 8-10 MBq of radiolabeled nanoparticle. PET image acquisition, reconstruction, decay correction, and region-of-interest (ROI) analysis were carried out as previously described.^{23 (link)} Quantitative PET data were presented as a percent of injected dose per gram of tissue (%ID/g) with 3-4 mice per group.

PET scans were performed using an Inveon microPET/microCT rodent scanner (Siemens Medical Solutions USA, Hoffman Estates, IL, USA). BxPC-3 or PANC-1 tumor-bearing mice were intravenously injected with 5–10 MBq (150 – 300 μCi) of ⁶⁴Cu-NOTA-heterodimer-ZW800, ⁶⁴Cu-NOTA-ALT836-F(ab′)₂-ZW800, or ⁶⁴Cu-NOTA-TRC105-F(ab′)₂-ZW800, and sequential static PET scans with 20 million coincidence events were acquired at 3, 12, and 24 h post-injection. NIRF imaging of ⁶⁴Cu-NOTA-heterodimer-ZW800 was performed immediately after each PET scan. After the last PET scan at 24 h post-injection, mice were euthanized, and the radioactivity was measured in the blood, tumors, and major organs/tissues using an automated γ-counter (Perkin Elmer, Waltham, Massachusetts, USA). Tracer uptake was reported as percentage injected dose per gram of tissue (%ID/g; mean ± SD). For blocking studies, BxPC-3 tumor-bearing mice were injected with 40 mg/kg of intact ALT836 or TRC105 at 12 h before administration of ⁶⁴Cu-NOTA-heterodimer-ZW800.