B7-H3, an immunomodulatory protein overexpressed in many cancers, is associated with tumor aggressiveness and poor prognosis, making it a crucial target for imaging to elucidate its role in cancer progression and guide therapeutic interventions. This study employed PET imaging to investigate the in vivo delivery and pharmacokinetics of two anti-B7-H3 antibodies, Ab-1 and Ab-2, in mouse xenograft models with varying B7-H3 expression levels. The antibodies were radiolabeled with [