The extent of ground-glass attenuation is a risk factor of chemotherapy-related exacerbation of interstitial lung disease in patients with non-small cell lung cancer

Objectives Chemotherapy-related acute exacerbation (AE) of interstitial lung disease (ILD) is observed in certain patients with non-small cell lung cancer (NSCLC) who have ILD. Although the prognosis of AE-ILD is extremely poor, there are no established risk factors for its occurrence. Therefore, we retrospectively investigated whether high-resolution computed tomography (HRCT) findings could identify risk factors for AE-ILD. Materials and methods Between January 2005 and December 2016, 35 patients with NSCLC who received chemotherapy at Hiroshima University Hospital and were diagnosed with ILD on HRCT were enrolled. The extent of ground-glass attenuation (GGA), reticulation, honeycomb appearance, and emphysema, as well as the presence of micronodules, traction bronchiectasis, and consolidation were evaluated in five levels of the lung bilaterally. The HRCT scores of GGA, reticulation, honeycomb appearance, and emphysema were determined by the following formula: 100 × sum of the extent of the HRCT findings/lung area. Results Thirty-five patients underwent various first- to fifth-line chemotherapy regimens. Nine patients (25.7%) developed AE-ILD. The median HRCT scores of GGA and reticulation were significantly higher in patients with AE-ILD than in those without. On univariate analysis, a GGA area score ≥ 24.8, reticulation area score ≥ 19.5, and KL-6 level ≥ 946 U/mL were significant risk factors. Multivariate logistic analysis revealed that only a GGA area score ≥ 24.8 was an independent risk factor of AE-ILD. Conclusions The GGA area on HRCT is a risk factor for chemotherapy-related AE-ILD. Therefore, this parameter can be used to predict the risk of AE-ILD before administering chemotherapy.