A COMPARISON OF SINGLE-DOSE AND FRACTIONATED TOTAL-BODY IRRADIATION ON THE DEVELOPMENT OF PNEUMONITIS FOLLOWING BONE-MARROW TRANSPLANTATION

Purpose: A review of 132 consecutive patients who received bone marrow transplant for various malignancies was conducted to determine factor s associated with increased risk in developing interstitial pneumoniti s (IF) as the result of total body irradiation (TBI). Twenty-four pati ents were excluded because 22 did not receive TBI and two had insuffic ient records. Methods and Materials: Patients were conditioned with TB I and various drug regimens. Eighteen patients received a single 6.0 G y dose of x-rays, The remaining 90 were treated with three doses of 3. 33 Gy separated by 24 h. All patients were followed for at least 18 mo nths for the purposes of determining the IP incidence, Results: Twenty -seven of these 108 (25%) patients developed IF; 19 (17.6%) died. The 2-year estimated incidence of IP was 24 and 18.6% for fatal IF. The et iology was determined to be idiopathic in 12 patients, the result of c ytomegalovirus in 6 patients, and caused by a variety of other infecti ous organisms in 9 patients. We were unable to demonstrate a statistic ally significant increase in IP with age (adults vs. children), dose r egimen, use of methotrexate for graft-vs.-host disease prophylaxis, th e presence of acute graft-vs.-host disease, time from diagnosis to tra nsplant, or transplant type (allogeneic vs, autologous). Conclusions: The incidence of fatal IP reported here is similar to that reported by other institutions utilizing hyperfractionated TBI protocols. Our dat a do not support the need for hyperfractionation to reduce the risk of IF.