[Treatment of leukemias and lymphomas with interferons: III. Trial treatment of meningeal localizations of acute leukemia and non-Hodgkin's lymphomas with beta interferon administered by the intrathecal route].

: Six patients with pure meningeal relapse of acute lymphoblastic leukemia (ALL) (5 patients) or leukemic lymphosarcoma (LS) (non Hodgkin's lymphoma) (NHL) (1 patient) were treated with intrathecal (I.T.) human fibroblastic interferon (IF beta), one vial (1.3 million units) every other day or every day up to remission or failure. Tolerance was excellent in all six patients with no local or general side effects. 5 patients had no improvement of their meningeal blast infiltrations after 5 to 8 injections and were given IT chemotherapy. The sixth patient achieved a complete remission (CR) after 11 injections, and was maintained in CR for eleven months under systemic and IT chemotherapy. IF cannot be proposed as standard treatment for meningeal leukemia, but we may be able to select a population of patients in which it could be indicated. Its combination with methotrexate and arabinoside cytosine, the two agents used IT which are S-dependent, has to be studied for a possible potentiation. Moreover, its good tolerance would permit its use in severe meningeal viral diseases.