High dose volume and low dose volume of the total and ipsilateral lung in prediction of acute radiation pneumonitis / 实用医学杂志

ABSTRACT

Objective To observe the incidence of acute radiation pneumonitis (ARP) in patients with nonsmall cell lung cancer treated by three-dimensional conformation radiotherapy or intersity-modulated radiation therapy,and investigate the predictive value of high dose volume and low dose volume of the total and ipsilateral lung on ARP.Methods 174 patients with non-small-cell lung cancer verified by pathology who received radical radiotherapy in our hospital from Aug 2013 to Nov 2015 were screened.Radioactive dose was 60 Gy-70 Gy,with 97 patients' dose of 60-64 Gy and 77 patients' dose of 65-70 Gy.Chemotherapy was done by paclitaxel + pentium first line treatment.155 patients were treated with radiotherapy alone and 19 with radiotherapy combined with chemotherapy.The V5～ V30,MLD (mean lung dose),V5ipis ～ V30ipsi,MLDipsi were calculated from the dose volume histogram system.The ARP was evaluated according to Common Toxicity Criteria 4.0 (CTC4.0).Univafiate and nultivariate analysis and receiver operating characteristic (ROC) curves were performed to assess the correlated factors of ARP.Results Of 174 patients,26 patients (14.94％) developed radioactive pneumonia at grade 2,11 patients (6.32％) at grade 3,2 patients (1.15％) at grade 4.The correlative factors included the radiochemotherapy regimen (sequential chemotherapy to radiotherapy or concurrent radiochemotherapy),V5,V10,V20,V30,MLD of the total lung and ipsilateral lung according to univariate analysis.Multivariate analysis of all the factors mentioned above showed the V5,V20ipsi and MLD were the independent predictive factors associated with ARP.ROC analysis indicated that the cut-off point of V5,V20ipsi,MLD were 62.38％,47.14％and 16.85Gy respectively.According to the V5,V20ipsi value,174 patients were divided into three groupsB group V5＜62％+V20ipsi≥47％,C group V5≥62％+V20ipsi＜47％,D group V5≥62％+V20ipsi≥47％.The chisquare test between the C group and D group has statistical significance.Conclusion V5,V20ipsi,and MLD are the independent risk factors of ARP.Compared with V5,limiting V20ipsi threshold is more likely to result in ARP.