A Clinical Study On Carotid Elsaticity In Patients Within The Early Stage Of Radiotherapy For Head And Neck Neoplasm By Echo-tracking Technique

Background and ObjectivesSome studies demonstrated that carotid artery stenosis appeared in patients with head or neck tumors 1-2 years later after radiotherapy, which indicated that late injury patterns happened to carotid artery after radiotherapy.Carotid stenosis may also lead to cerebrovascular accident such as stroke and threat human survival quality seriously. In the past, traditional imaging methods were used to assess artery injury of head and neck tumor patients and vascular damage was diagnosed after morphologic changes were identified. Recent studies showed that artery elasticity change happened more early than that of structural change. Echo-tracking as a new noninvasive technology for artery elasticity could tell arterial elasticity rapidly and accurately before morphological changes, and that assess arteriosclerosis degree in vessel wall quantitatively.This study aims to explore the changes of carotid artery elasticity and that evaluate the possibility of related parameters as markers for early damage in carotid artery in patients with head or neck tumors after radiotherapy by Echo-racking technology, which could provide evidence for clinical preventative intervention measures.MethodsAccording to the process of radiotherapy,42 patients were divided into 3 groups: Group A: l-3days before the radiotherapy; Group B:2.5-3 weeks of the radiotherapy time, (Radiation dose for 26-30 Gy); Group C:5-6 weeks of the radiotherapy time, (Radiation dose was 50-60 Gy). Measure and record the patients heart rate (HR)and Brachial artery systolic blood pressure (SBP), diastolic blood pressure (DBP), Calculation and record the pulse pressure(PP). Conventional parameters such as intima thickness (IMT), resistance index (RI), pulsatility index (PI) and systolic to diastolic (ratio) (S/D), Internal systolic diameter(Ds), and internal diastolic diameter(Dd) were measured. Elastic parameters such as atiffness parameter (β), pressure-strain elastic modulus (Ep), pulsed wave transmittal velocity (PWVβ), arterial compliance (AC) and augment index (AI) were measured with ET technique. Comparing three groups of patients with carotid ET test parameters and carotid artery conventional ultrasound measurement data,△D, blood pressure and heart rate.Results1. The results of ET showed thatβ, Ep and PWVβof group B and group C were significantly higher than those in Group A(P<0.05). AC of Group B and Group C were significantly lower than that in Group A (P<0.05).β, Ep and PWVβof Group C were significantly higher than those in Group B(P<0.05). AC of Group C were significantly lower than that in Group B (P＜0.05). There was no significant difference of the AI in all groups (P>0.05).2. Conventional ultrasonic shows that there was no significant difference of the IMT, RI, PI, S/D, Ds and Dd in all groups (P>0.05). The△D of group B and group C were significantly lower than that in Group A (P<0.05). The△D of group C were significantly lower than that in Group B (P＜0.05).3. Parameters of clinical shows that there was no significant difference of the SBP DBP,PP and HR in all groups (P>0.05). 4.△D is negative correlated withβ, Ep and PWVβ(r=-0.843,-0.868,-0.922, P<0.01),and positive correlated with AC (r=0.791, P<0.01), have no linear correlation with AI (r=-0.186, P>0.05).The parameters ofβ, PWVPare positive correlated with Ep (r=0.976,0.986, P<0.01).p are positive with PWVp (r=0.956, P<0.01).Ep and PWVβare negative correlated with AC (r＝-0.695, P<0.05,-0.710,-0.758, P<0.01).p, Ep,AC and PWVβhave no linear correlation with AI (r=0.193,0.195,0.184,-0.232, P>0.05)Conclusions1. The function of carotid elasticity changes in the early time of head and neck tumor radiotherapy. ET technique provides the accurate quantitative detection to the early injury of patients'carotid with head and neck radiotherapy.2. The elasticity of carotid decreased with the increase of radiation dose in the early time of head and neck neoplasm radiotherapy. There is a correlation between them.3. ET technology gets more comprehensive, reliable, sensitive reflection of changes in arterial elasticity.