The Study Of Application Of Cardiac Troponin T Combined With Dose-volume Histogram (dvh) In Detecting Radioactive Myocardial Damage

Objective: Cardiac troponin T(cTnT) is highly sensitive and specific for detecting myocardial damage.In this inspection,acquiring the dose and volume which was absorbed in heart from dose-volume histogram(DVH) and measuring the change of electrocaidiogram to explore a clinical value of cTnT in detecting myocardial damage when the heart was exposed to chest tumor radiotherapy.Methods: There are 38 patients with chest tumor who had the primary radiotherapy,20 men and 18 women,16 patients with left breast cancer.15 patients with esophageal carcinoma, 16 patients with lung carcinoma.They are 36 to 94 years old.We use 6-MV X-ray or 10-MV X-ray to treat them.The character of these patients must have accurate diagnosis,normal kidney function,normal electrocaidiogram,chemotherapy treatment and cTnT in the normal range before radiotherapy.The DVH of heart in radiotherapy for all patients and dose on the 3D therapy planning system was analyzed using 3D reconstruction of CT image.These patients were put into radiotherapy of 2Gy per day,5 times per week.The whole process need 3 to 8 weeks.The cTnT of all patients were detected when 30Gy,40Gy,50Gy and before radiotherapy.Then measure electrocaidiogram and analyse the dose and volume which was absorbed in heart from DVH.Results: There are 3 patients whose heart was radiated beyond one-third volume when 30 Gy of radiotherapy dose. In this 3 patients,45% area of heart was radiated in 2 patients.One patient has abnormal electrocaidiogram,but the lever of cTnT is in the normal range.Through treated,when the heart function was cured,this patient complete radiotherapy.The cTnT in one patient was higher than heathy person(cTnT>0.03ng/ml),65% area of heart was radiated,but the electrocaidiogram is normal.The radiotherapy in this patient was stopped.Conclusions:cTnT is highly sensitive and specific for detecting myocardial damage.So detecting the cTnT in chest tumor radiotherapy can help us diagnose myocardial damage early and improve treat plan in order to prevent and treat complications and residuals ror radiotherapy as soon as possible.