The predictive value of basic lung function and dosimetric parameters of acute radiation pneumonitis during the treatment of concurrent chemoradiotherapy

Abstract

Objective To observe the incidence of RP in NSCLC and esophageal carcinoma treated with 3DCRT and investigate the relationship between acute RP and lung function and dosimetric parameters.Methods From October 2006 to August 2008, 3DCRT plus concurrent chemotherapy of NP or LFP were applied to 64 patients with locally advanced NSCLC or esophageal carcinoma. twenty-three patients suffered form NSCLC and 41 patients from esophageal carcinoma, the prescription doses were 60 Gy/30fx and 58 -64 Gy/29 -32fx, respectively. Results For patients with esophageal carcinoma, 34% developed RP(9 grade 1,3 grade 2 and 2 grade 3). For patients with NSCLC, 96% developed RP(9 grade 1, 8 grade 2 and 5 grade 3). There was significant difference between the two groups(t =5. 55,P=0. 000). The FEV1.0/FVC and DLCO of patients with NSCLC were significantly lower than those of esophageal carcinoma, the ratio were 75.6%:82.7%(t=2.75,P=0.008)and 71.7%:81.0%(t=2.50, P=0.015),respectively. For patients whose FEV1.0, FEV1.0/FVC%, DLCO ＜80% and ≥80% before irradiation,the incidence of ≥2grade ARP were 35% vs 25% ,31% vs 26% and 35% vs 19%, respectively(x2 = 1.81,0.15,2. 13,P =0.179,0.697,0.144). While for patients whose FEV1.0 ＜ 70% and ≥70%, the incidence of severe ARP were 67% and 22% ,respectively(x2 =5.64, P =0.018). Spearman correlated analysis indicated that all the dosimetric parameters had relation with ≥ 2 grade ARP . The V20 of lung and MLD were found independently associated with RP according to multivariate analysis(x2 = 4.61,6.97, P = 0.032,0.008).Conclusions Parameters of basic lung function can predict the incidence of ≥2 grade RP to some extent,especially when the value of FEV1.0, FEV1.0/FVC%, and DLCO was lower. However, the V20 of lung and MLD may be the most valuable predictors. Key words: Lung neoplasms/radiotherapy; Esophagus neoplasms/radiotherapy; Radiotherapy,three-dimensional conformal; Radiation pneumonitis; Lung function