20 Years of Experience in Static Intensity-Modulated Total-Body Irradiation and Lung Toxicity

Abstract

To analyze lung complications after allogeneic or autologous transplantation following total-body irradiation (TBI) with compensators, so-called sIMRT (static intensity-modulated radiotherapy). Between 1983 and 1998, 257 patients with different hematologic malignancies underwent TBI in six fractions to a total dose of 12 Gy within 3 consecutive days (212 with 11 Gy lung dose) prior to allogeneic (n = 174) or autologous (n = 83) transplantation. 40 patients were < 16 years of age. Minimum follow-up time was 5 years. Median follow-up period was 110 months (13–231 months). 5-year survival rate was 47.9%, 5-year tumor-related mortality 23%, 5-year treatment-related mortality 29.2% (12 Gy lung dose: 53.3% ± 14.6%, 11 Gy: 24.1% ± 5.7%). Interstitial pneumonitis (IP) developed in 28 of 257 patients (10.9% ± 3.8%). IP incidences in the allogeneic and autologous groups were 14.4% (± 5.6%) and 3.6% (0–7.6%), respectively. IP incidences with 12/11 Gy lung dose were 22% (± 12%)/8.5% (± 3.7%). IP mortality was 9.3% (± 3.6%). 13 of 28 patients with IP had a cytomegalovirus infection, five an acute graft-versus-host disease grade IV of the lungs. IP incidences with 12/11 Gy lung dose were 25% (9–50%)/4.2% (0.2–19.1%) in patients < 16 years, and 20.7% (9.4–37.4%) and 13.3% (± 6.5%) in older patients after allogeneic transplantation. Compensator-generated static intensity-modulated TBI with a total dose of 12 Gy and a lung dose of 11 Gy is a modern and comfortable treatment with moderate lung toxicity, small dose inhomogeneities and little setup failure before transplantation. Especially patients < 16 years of age benefit from lung dose reduction.