Objectives: To observe the risk factors affecting the occurrence of RP after gemcitabine-based induction chemotherapy.
Methods: Between January 2010 and December 2017, patients with NSCLC received gemcitabine or docetaxel chemotherapy, followed by radiotherapy at Zhejiang cancer hospital were enrolled in this study. Patients were treated with gemcitabine or docetaxel induction chemotherapy, followed by radiotherapy or concurrent chemoradiotherapy. Acute radiation pneumonitis was scored post chemoradiotherapy.
Results: One hundred and eighty-four patients with NSCLC were included in the gemcitabine group and 144 in the docetaxel group. The gemcitabine group experienced a higher incidence of grade ≥ 2 RP, compared with docetaxel group (25.5% Vs. 13.2%, P = 0.005). The optimal cutoff values of lung V5, V20, V30 and MLD were set at 44% (AUC [area under the curve] = 0.593), 24% (AUC = 0.607), 14.2% (AUC = 0.622) and 1226 cGy (AUC = 0.626). On multivariate analysis, only lung V30 was identified as a predictor for grade ≥ 2 RP (P = 0.03). The grade ≥ 2 RP rate was only 9.4% for the low-risk group (Lung V5 ≤ 44%, V20 ≤ 24%, V30 ≤ 14.2%, and MLD ≤ 1226 cGy) in patients received gemcitabine induction chemotherapy.
Conclusions: Gemcitabine chemotherapy before thoracic radiotherapy in NSCLC patients was related to a higher incidence of grade ≥ 2 RP, compared with docetaxel chemotherapy. The Lung dose-volume variable V30 was the best predictor of grade ≥ 2 RP.
Keywords: Dose-volume variable; Non-small cell lung cancer; Radiation pneumonitis; Risk factor.