Total body irradiation of chronic lymphocytic leukemia: Incidence and duration of remission

Abstract

The results of total body irradiation for 17 consecutive patients with symptomatic (active) chronic lymphocytic leukemia who had received no prior therapy are reviewed. All patients were given an induction course of treatment and subsequently observed without maintenance therapy to determine the duration of remission. Using a described classification to measure therapeutic response, 16 of the 17 patients were evaluated to have had favorable clinical responses. Eight of these responders had complete disappearance of palpable disease and symptoms, correction of anemia when present, and restoration of the white blood count and differential count to normal following completion of therapy (Type I response). The remaining 8 responders had less complete but definite improvement both objectively and subjectively (Type II response). The duration of unmaintained remission was measured from completion of induction therapy to relapse, the latter being defined as any evidence of recurring disease, even though asymptomatic. The median duration of remission was significantly longer for the Type I (19 months) as compared to the Type II (4 months) responders. This parallels the experience with both experimental L1210 and human acute leukemia wherein the duration of unmaintained remission is inversely related to the number of residual leukemic cells surviving treatment. The ability to achieve these high quality remissions offers some prospect of materially improving both the quality of life and survival time of chronic lymphocytic leukemia patients in the future.