Accelerated LTI, but not conventional LTI, therapy induces potent T cell–mediated durable complete remissions in A20 lymphoma. (A) Changes in individual tumor volumes of A20 lymphomas after subcutaneous (s.c.) flank injection of 2 × 105 lymphoma cells in untreated BALB/c mice. Fraction of mice alive with complete remission of primary tumors at day 60 is shown. (B) Changes in mice treated with accelerated (acc) tumor irradiation (10 × 3 Gy) over 4 days. (C) Changes in mice treated with conventional (conv) daily tumor irradiation over (10 × 3 Gy) 12 days. (D) Tumor host survival of treated and untreated tumors. There were significant differences in survival over 100 days in groups with untreated tumors vs tumors treated with acc irradiation (P < .0001) or conv irradiation (P < .0001), as well as in groups treated with acc irradiation vs conv irradiation (P = .006, Mantel-Cox test). Changes in mean (± standard error) tumor volumes (E) and survival of tumor hosts (F) after tumor cell injection (2 × 105 A20 cells, s.c.) into untreated mice or into mice in complete remission (cured) for ≥100 days after treatment of A20 tumors with accelerated LTI. (G) Survival of untreated mice or adoptive BALB/c hosts given 800 cGy total body irradiation and 5 × 106 TCD BM cells alone or with 6 × 106 splenic T cells from mice in complete tumor remission. Adoptive hosts or untreated mice were injected with lymphoma cells (2 × 105 of A20 cells, s.c.) on the day of BM injection. There was a significant difference in survival between groups with T-cell transplants from cured LTI-treated donors (n = 5) vs transplants of TCD BM alone (P = .0003; n = 5) vs survival of untreated tumor-bearing mice (P < .0001; n = 5).