Related Factors For Radiation-Induced Heart Damage In Lung Cancer After Intensity Modulated Radiation Therapy

Objective: To observe acute radiation-induced heart damage(RIHD)and its related factors in the patient with lung cancer which treated with intensity modulated radiation therapy(IMRT).Methods: From October 2015 to March 2017,61 patients who suffered from lung cancer.RIHD was evaluated with RTOG standard.The dosimetric parameters was described from dose volume histogram(DVH).The related clinical and dosimetric parameters were evaluated by Spearman correlatived and Mann—Whitney rank sum test.Linear regression used to diagnosis multiple collinearity and rectify it.Logistic regression used to multivariate analysis.Result: The overall incidence rate of RIHD was 49.2%(30 patients),27 cases were grade1.0 and 3 cases were grade 2.0.According to Spearman correlatived analysis,the correlatived factors included sex,tumor classification,clinical N stage and history of hypertension(r=-0.241?-0.241?-0.253?0.258,P<0.05).According to Mann—Whitney rank sum test,the differences had statistics significance between RHID and non-RHID group,which included heart V5-V50,heart medium dose,heart volume,PTV/heart volume and Dmean,D50,V5-60 of left atrium,Dmean,D50,V20 pf left ventricle,Dmean,D50,V5,V20 of right atrium and Dmean,D50,V5-50 of right ventricle(P<0.05).Those above factors were put into multivariate analysis history of hypertension,heart volume,PTV/heart volume and right ventricle DVH variable were independent predicted factors(Wald=4.656,10.176,5.388,7.548,P=0.031,0.001,0.02,0.006).According to Spearman correlatived analysis about lung and right ventricle,the most correlatived factors was MLD and D50 of right ventricle(r=0.357,P<0.05)?Conclusion: Patients with smaller heart volume and larger PTV/heart volume could increase radiation-induce heart damage,especially patients with history of hypertension.Right ventricle DVH can assess and predict radiation-induce heart damage,especially D50.