Quantification of the radioactivity in Bq for the different steps involved during the in vivo experiments for mouse 1 injected with 0.95 kBq of 68 Ga-smSiP and mouse 2 injected with 2.9 kBq. All the measurements are decay-corrected to the time of injection for better comparison. Inj, activity measured in a gamma counter before the injection; Biod, activity in the lungs measured by gamma counter during the biodistribution studies; Lgs, activity in the 20 µm lung tissue slice measured by gamma counter; Ar, activity in the 20 µm lung tissue slice measured by autoradiography. Data are presented as mean ± s.d.