The goals of the current study were: (1) to evaluate the biodistribution of the 2G11 mAb using multiple tumor lines within an OS xenograft model; (2) perform pilot RIT of OS with 2G11 mAb radiolabeled with beta-emitter 177Lutetium (177Lu); (3) to assess 2G11 ability to bind to IGF2R in canine OS tumors from companion dogs as a prelude to demonstrating the efficacy and safety of RIT in animal models of compelling translational significance. Here, IGF2R is linked to neoplasm.