Consequences of two different doses to the lungs during a single dose of total body irradiation: results of a randomized study on 85 patients.

ABSTRACT

PURPOSE: To evaluate the incidence of lung complications and leukemia recurrences after two different doses to the lungs during total body irradiation. METHODS AND MATERIALS Seventy-nine patients with acute leukemia (AML or ALL) in first complete remission or chronic myeloid leukemia in the chronic phase, five patients with high grade lymphoma, and one with chronic lymphocytic leukemia were entered in the study. They were given a single dose of total body irradiation (10 Gy over 4 h) with two different doses to the lungs (6 Gy or 8 Gy) prior to bone marrow transplantation. The median dose rate was 0.04 Gy/min. The median follow-up for both groups of patients was 24 months. RESULTS: The actuarial 5-year overall survival rate was similar in both groups, 59% and 43% for patients given 8 Gy and 6 Gy to the lungs, respectively. The lung complication rate was similar in the two groups (28% vs. 22% for the 8 Gy and 6 Gy group, respectively). The actuarial leukemia recurrence rate was significantly higher in the group of patients given 6 Gy to the lungs (25%) vs. 0% in the 8 Gy group. Interestingly, all recurrences occurred in the group of patients who were given 6 Gy to the lungs, who had acute leukemia, and no chronic graft vs. host disease (GVHD). CONCLUSIONS: Although the number of patients was not very large and the follow-up relatively short, these findings suggest that a lower dose to the lungs could lead to an increased incidence of leukemia recurrences due to a lower dose to the thoracic wall or to lower incidence of chronic GVHD.