The control of chronic lymphocytic leukemia with mediastinal irradiation.

Forty patients with chronic lymphocytic leukemia have been treated with mediastinal irradiation. A full remission was achieved in 18 (45 per cent) patients, a partial response in eight (20 per cent), "WBC control" in eight (20 per cent) and no response in 6 (15 per cent). Although mediastinal irradiation benefited all stages of disease, earlier stages of disease correlated with more complete and longer response to mediastinal irradiation. Toxicity was mild and transient and included leukopenia in five patients (12 per cent), thrombocytopenia in eight patients (20 per cent), mild esophagitis in 12 patients (30 per cent) and pneumonitis in four patients (10 per cent). There were no toxic deaths and mediastinal irradiation did not adversely effect survival. Treatment was readily given on an ambulatory basis and completed within four weeks. In five of 11 patients, abnormal immunoglobulins became normal. Eleven patients had abnormal lymphocyte transformation with PHA, five had marked improvement and three had partial improvements following mediastinal irradiation. This improvement appeared to correlate with response and survival but further study is necessary to confirm this relationship. Although most patients required additional therapy within two years, eight patients have required no further therapy for periods of twenty-eight months to thirteen years.