Figure 1. Timeline of the animal experimentation.

Athymic nu/nu female mice were inoculated subcutaneously on the right posterior leg with SKBr3 (HER2+/MUC4-) cells and on the left with JIMT1 (HER2+/MUC4+) cells. Imaging and treatments were initiated two weeks after inoculation when tumors reached approximately 0.5 cm³. Mice were randomized to four different groups: (1) the CS group receiving sweetened drinking water and i.p. saline injections (n = 10), (2) the CT group receiving sweetened drinking water and trastuzumab injections (i.p., 5mg/kg (n = 10), (3) the NS group receiving sweetened drinking water supplemented with NAC and saline i.p. injections (n = 9), and (4) the NT group receiving sweetened drinking water supplemented with NAC and trastuzumab injections (i.p., 5mg/kg) (n = 10). Imaging studies were conducted using a μPET-CT and each mouse was scanned three times, with an ¹⁸F-FDG and ⁸⁹Zr-Trastuzumab PET-CT before treatment and an ¹⁸F-FDG PET-CT post treatment. Images were recorded for ¹⁸F-FDG at 1h and ⁸⁹Zr-Trastuzumab 6 days after injection respectively. After the last scan, animals were euthanized and an ex-vivo body distribution study was performed. A pathological examination was also conducted on a subset of animals from each cohort with immunostaining of HER2, MUC4, pAkt and Ki67.