Prospective evaluation of early lung toxicity following three-dimensional conformal radiation therapy in nonsmall-cell lung cancer: Preliminary results

Purpose: Radiation pneumonitis is the restricting complication following lu ng cancer irradiation. The correlation between dose-volume histograms (DVHs ) and pneumonitis, with a clinical, radiological, and respiratory function evaluation was assessed. Special endpoint was the evaluation of respiratory function after three-dimensional conformal radiotherapy (3D-CRT), Methods and Materials: Fifty-four patients with non metastatic non-small-ce ll lung cancer (NSCLC) were treated with a curative intent with 3D-CRT (66 Gy), Thirty-one patients were treated postoperatively (pneumonectomy in 9 p atients) for residual tumor or massive nodal involvement (N2 or N3); 23 pat ients were treated,vith exclusive radiotherapy. Clinical evaluation, CT sca n, and pulmonary functional tests were performed before and 6 weeks after i rradiation. The DVHs were calculated applying lung density heterogeneity. Results: Twenty patients had radiation pneumonitis. Irradiation significant ly decreased total lung capacity. Volume of the PTV2 (more than 200 cm(3)) was a significant prognostic factor for lung complication. Conclusion: DVHs combined with initial pulmonary functional tests can predi ct pulmonary toxicity and could allow us to adjust volume that received tot al highest dose with acceptable toxicity. (C) 2000 Elsevier Science Inc.