Application of a radiation pneumonitis prediction model in patients with locally advanced lung squamous cell cancer

Abstract

Background:The aim of the present study was to establish a new prediction model for radiation pneumonitis (RP) in locally advanced non-small cell lung cancer (LA-NSCLC) patients before and after radiotherapy. Methods:The study involved 153 patients. Age, arterial partial oxygen pressure (PO 2 ), forced vital capacity, pulmonary emphysema (PE), subclinical interstitial lung disease (sILD), and dosimetric parameters, such as mean lung dose and percentage of lung volume, and a dose >5/20 Gy (V5/V20), were considered candidate RP predictors.Results: Of the 153 eligible patients, 33 (21.6%) developed RP, 68 had PE (43.8%), and 24 (15.7%) had sILD. Grades 2, 3, and 5 RP were scored in 17 (11.1%), 15 (9.8%), and 1 (0.7%) patient/s, Grade 4 RP was not observed. Grades 1, 2, and 3 PE were scored in 45 (29.4%), 22 (14.4%), and 1 (0.7%) patient/s. Grades 0 and 1 sILD were observed in 129 (84.3%) and 24 (15.7%) patients. Univariate analysis found age, PE, and sILD to be significantly correlated with grade ≥2 RP. Multivariate analysis revealed age >68 years, PE grade >1, and sILD grade ≥1 as independent risk factor for grade ≥2 RP in LA-NSCLC with squamous cell carcinoma (SCC). Finally, a new predictive risk score (PRS) comprised of these factors was developed. The PRS score was 0, 3-5, and 6-11 when the cumulative incidence of grade ≥2 RP was 8.8% (5 patients), 13% (3 patients), and 84.6% (13 patients) (P=<0.001).Conclusions: Age, PE, and sILD could independently and significantly predict RP in LA-NSCLC with SCC.