Indium-111-labeled tumor-infiltrating lymphocytes (111In-TIL) were transferred as an intrahepatic arterial bolus to determine their in vivo distribution in patients with hepatic malignancies. In the in vitro culture system, TIL were expanded upon simultaneous stimulation by recombinant interleukin-2 (rIL-2) and immobilized anti-CD3 monoclonal antibody. This double activation led not only to a larger cell yield, but also to a significantly more dominant subpopulation with CD4+ phenotype than occurred with activation by rIL-2 alone. Accumulations of 111In-TIL in the liver were identified by scintigraphy in all of three patients, corresponding to the tumor localization by computed tomography. Such accumulation had persisted for at least 48 hours after infusion. After intraarterial chemoimmunotherapy that included TIL, two of three patients achieved a partial therapeutic response. The authors conclude that their method of culture and transfer can facilitate the accumulation of TIL at tumor sites, which may augment the antitumor effects of adoptive immunotherapy.