total lymphoid irradiation
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total lymphoid irradiation (TLI)
a method of inducing a strong immunosuppressive effect in patients undergoing bone marrow transplants, treatment of certain lymphomas, or other therapies requiring immunosuppression. TLI involves exposing all lymph nodes, the thymus, and spleen to a total of 2000 rad in 100-rad doses from a linear accelerator before graft implantation.