A preclinical study in solid tumor models found that intraperitoneal CAR-T administration outperformed standard intravenous delivery in antitumor efficacy. Regional delivery improved CAR-T cell persistence systemically and within tumor tissue, enhanced local infiltration, and shifted trafficking dynamics observed by in vivo PET-CT using labeled cells. The researchers also evaluated combination strategy by pairing intraperitoneally delivered CAR-T with an anti-angiogenic agent, anlotinib, to further support tumor control. The imaging and flow-cytometry evidence together point to delivery barriers as a primary limiter in solid tumors. For translational work, the key implication is that route-of-administration and tumor compartment access may be as decisive as target selection when moving CAR-T into solid tumor indications.