Chemoradiotherapy (CRT) for locally-advanced (LA) lung cancer patients with interstitial lung abnormalities (ILA).

e20057 Background: Interstitial lung disease (ILD) is an independent risk factor for lung cancer. The incidence of ILD in lung cancer patients is 5–10%. Although CRT is the standard treatment for LA lung cancer and has potential for long-term disease-free survival or cure, the treatment is avoided in patients with ILD because of the risk of severe radiation pneumonitis or acute ILD exacerbation. ILA has recently been evaluated using high-resolution computed tomography (HRCT) to assess interstitial changes. The aim of this study was to determine the feasibility and efficacy of CRT for LA lung cancer patients with ILA. Methods: Patients who underwent CRT for LA lung cancer at Okayama University Hospital between 2012 and 2015 were reviewed retrospectively. HRCT prior to treatment was evaluated by one pulmonologist and two radiologists using sequential reading. Results: Of 74 patients, ILA was present in 25 (33.8%) and indeterminate ILA was present in 23 (31.1%); 26 patients (35.1%) did not have ILA. Patient characteristics are shown below. Desaturation at rest (SpO2< 95%) and honeycombing on HRCT were not observed in patients with ILA. Only one patient with ILA had a low vital capacity (VC% of predicted, < 80%). Severe radiation pneumonitis (≥ grade 2) occurred in 32.0% of patients with ILA and 19.2% of patients without ILA (P=0.35). All radiation pneumonitis was controllable and grade 4 or 5 was not observed. Using multivariate analyses, treatment > 20 Gy involving > 25% of the lung volume was a predictive factor for severe radiation pneumonitis, but not ILA. The 2-year survival percentages of patients with and without ILA were 56.8% and 72.5%, respectively (hazard ratio, 1.21; 95% confidence interval, 0.76–1.90; P=0.42). Conclusions: Although severe radiation pneumonitis tended to increase, CRT was appropriate for patients with ILA without desaturation, low VC, and honeycombing on HRCT. [Table: see text]