A Study Of The Correlation Between Subclinical Interstitial Lung Disease And Radiation Pneumonitis

1.A study of the correlation between subclinical interstitial lung disease and radiation pneumonitis in patients with small-cell lung cancerObjectivePrevious studies reported that patients with subclinical interstitial lung disease were more susceptible to developing radiation pneumonitis after thoracic radiation therapy.The present study aimed to evaluate the incidence and predictors of radiation pneumonitis after thoracic radiation therapy in patients with small-cell lung cancer with or without subclinical interstitial lung disease.Methods and MaterialsA total of 95 consecutive patients with small-cell lung cancer between January 2015 and December 2015,who were treated with thoracic intensity-modulated radiation therapy in our institutions,were analyzed.The diagnosis of subclinical interstitial lung disease was based on the pretreatment high-resolution computed tomography imaging,such as honeycombing,subpleural reticular opacities,ground-glass opacity,and traction bronchiectasis.Univariate and multivariate analyses were used to assess the correlation of clinical factors,preexisting subclinical interstitial lung disease,and dose-volume histogram-based dosimetric parameters with radiation pneumonitis.ResultsFifteen(15.8%)patients had subclinical interstitial lung disease.The incidence of grade>2 and>3 radiation pneumonitis at 1 year was 27.1%and 12.7%in the entire cohort,respectively.Subclinical interstitial lung disease was associated with an increased risk of grade≥2 RP(50.0%in subclinical interstitial lung disease+vs 23.3%in subclinical interstitial lung disease-,P=0.017)and grade≥3 RP(35.8%in subclinical interstitial lung disease+vs 8.9%in subclinical interstitial lung disease-,P=0.005)at 1 year.Subclinical interstitial lung disease and smoking history(≥40 pack-years)were significant predictors of grade>3 RP in multivariate analysis(P=0.023 and 0.012,respectively).ConclusionsPreexisting subclinical interstitial lung disease and smoking history(≥40 pack-years)are associated with an increased risk of grade>3 RP after thoracic radiation therapy in patients with small-cell lung cancer.2.Risk factors of radiation pneumonitis in lung cancer patients with subclinical interstitial lung disease after thoracic radiation therapy:an observational studyObjectivePrevious studies reported that patients with subclinical interstitial lung disease were more susceptible to developing radiation pneumonitis after thoracic stereotactic body radiotherapy or thoracic 3-dimensional conformal radiotherapy.The present study aimed to evaluate the incidence and risk factors of radiation pneumonitis after thoracic intensity-modulated radiation therapy in lung cancer patients with subclinical interstitial lung disease.Methods and MaterialsConsecutive patients with subclinical interstitial lung disease between January 2016 and December 2017,who were treated with thoracic intensity-modulated radiation therapy to a prescribed dose of>50 Gy in our institutions,were prospectively analyzed.The diagnosis of subclinical interstitial lung disease was based on the pretreatment high-resolution computed tomography imaging,such as honeycombing,subpleural reticular opacities,ground-glass opacity,and traction bronchiectasis.Statistical analysis was performed using SPSS software 22.0 for Mac.Univariate and multivariate analyses were used to assess the correlation of clinical factors,dose-volume histogram-based dosimetric parameters,and radiological features of subclinical interstitial lung disease with radiation pneumonitis.A P value<0.05 was considered statistically significant.ResultsA total of 87 consecutive lung cancer patients with subclinical interstitial lung disease were enrolled.The median follow-up time was 14.1 months.Radiation pneumonitis was observed in 19(21.8%),27(31.0%),10(11.5%),3(3.4%),and 5(5.7%)patients with grade 1,2,3,4 and 5 RP,respectively.The location of tumors and mean lung dose were significantly associated with grade≥2 radiation pneumonitis in univariate analysis(P=0.043,P=0.024,respectively).Patients who have received chemotherapy with gemcitabine in the past and involvement of subclinical interstitial lung disease>25%of the lung volume were significantly associated with grade>3 radiation pneumonitis in univariate analysis(P=0.031,P=0.037,respectively).MLD was a significant risk factor for grade>2 RP in multivariate analysis(P=0.042).Patients who have received chemotherapy with gemcitabine in the past and involvement of subclinical interstitial lung disease>25%of the lung volume were significantly associated with grade>3 RP in multivariate analysis(P=0.046,P=0.017,respectively).ConclusionsSubclinical interstitial lung disease is associated with an increased risk of radiation pneumonitis.MLD was a significant risk factor for grade>2 RP.Patients who have received chemotherapy with gemcitabine in the past and involvement of subclinical interstitial lung disease>25%of the lung volume are associated with an increased risk of grade>3 radiation pneumonitis.3.A study of the predictive effect of serum fibrosis markers on radiation pneumonitisObjectivePrevious studies reported that the levels of serum fibrosis markers changed in animal models of radiation pneumonitis.It suggested that serum fibrosis markers maybe involved in the occurrence of radiation pneumonitis.The purpose of this study was to evaluate the prediction of serum fibrosis markers on radiation pneumonitis and risk factors of radiation pneumonitis.Methods and MaterialsPatients with lung cancer between May 2016 and August 2018,who were treated with thoracic intensity-modulated radiation therapy to a prescribed dose of>50 Gy in our institutions,were prospectively analyzed.The levels of type III procollagen N-terminal peptide,type IV collagen,laminin and hyaluronic acid in serum were measured by radioimmunoassay before and at 40 Gy of radiotherapy.Statistical analysis was performed using SPSS software 22.0 for Mac.Univariate and multivariate analyses were used to assess the correlation of serum fibrosis markers with radiation pneumonitis and risk factors of radiation pneumonitis.A P value<0.05 was considered statistically significant.ResultsA total of 123 lung cancer patients with subclinical interstitial lung disease were enrolled.The median follow-up time was 13.9 months.Radiation pneumonitis was observed in 30,18,2 and 1 patient with grade 1,2,3 and 5 radiation pneumonitis,respectively.No patient suffered from grade 4 radiation pneumonitis.The incidence of grade>2 radiation pneumonitis was 17.1%.The levels of serum type IV collagen>62.20ng/ml,mean lung dose,V10,V20,V30 and subclinical interstitial lung disease were associated with an increased incidence of grade>2 radiation pneumonitis in univariate analysis.Subclinical interstitial lung disease and mean lung dose were significantly associated with grade>2 radiation pneumonitis in multivariate analysis(P=0.033,P=0.029,respectively).The levels of serum type IV collagen before radiotherapy may be associated with subclinical interstitial lung disease(P=0.043).ConclusionsPreexisting subclinical interstitial lung disease and mean lung dose are predictors of grade>2 radiation pneumonitis.Serum fibrosis markers were not found to be significant factors influencing radiation pneumonitis.