Prospective evaluation of pulmonary function in cancer patients treated with total body irradiation, high-dose melphalan, and autologous hematopoietic stem cell transplantation

Pulmonary function tests (standard vital capacity, SVC; total lung capacity, TLC; forced expiratory volume in 1 second-forced vital capacity ratio, FEV1/FVC; carbon monoxide transfer factor, DLCO) were prospectively evaluated in patients (median age 25 years, 13-52 years; median follow-up 20 months, 6-51 months) with Hodgkin's disease (15 patients), non-Hodgkin's lymphoma (9 patients), and inflammatory breast cancer (3 patients) treated with sequential high-dose therapy comprising the following phases over approximately 2 months: a) cyclophosphamide (7 g/m2); b) vincristine (1.4 mg/m2), methotrexate (8 g/m2), and cisplatinum (120 mg/m2) or etoposide (2 g/m2); c) total body irradiation (TBI; 12.5 gy, 5 fractions over 48 hours), intravenous melphalan (120-180 mg/m2), and transplantation of autologous peripheral blood and/or bone marrow hematopoietic stem cells. Within 2 months after transplantation, 12 patients also received 25 Gy radiotherapy boost to mediastinum and clavicular regions. In vivo dosimetry evaluations of fractionated TBI treatments showed that mean radiation dose absorbed by lungs was 12.18 Gy (97.4% of TBI dose). Despite such a high radiation dose, we observed only transient and subclinical decrease of SVC, TLC, and DLCO. The decrease of SVC, TLC, and DLCO was more evident and prolonged in patients receiving radiotherapy boost. All parameters progressively recovered to normal values within 2 years after transplantation. In contrast, FEV1/FVC remained within normal limits in all patients, thus demonstrating the absence of obstructive ventilatory changes. In addition, no interstitial pneumonia was observed.