三维放疗前后血清心肌酶谱变化与心脏体积剂量相关性分析

目的 探讨胸部肿瘤患者三维放疗前后血清心肌酶谱改变与心脏体积剂量的相关性。方法 102例胸部肿瘤患者(肺癌 68例、食管癌 34例)放疗前后检测血清天冬氨酸氨基转移酶(AST)、肌酸激酶(CK)、CK同工酶(CK-MB)、乳酸脱氢酶(LDH)及α-羟丁酸脱氢酶(α-HBDH)水平。放疗前后各种酶水平比较行配对t检验,组间比较行成组t检验。采用剂量体积直方图(DVH)参数\心脏接受≥x Gy照射体积占总体积百分比(Vx)\]评价心脏体积剂量,各种酶与DVH参数相关性行Pearson法分析。结果 放疗后血清AST、CK-MB、LDH、α-HBDH水平较放疗前明显增高(19.42∶27.89、14.72∶19.57、178.80∶217.57、140.32∶176.25,t=－3.39~－6.92,P均=0.000)。调强放疗前后AST变化与 V₂₀、V₂₅、V₃₀相关(r=0.302~0.431,P=0.039~0.003),CK变化与 V₃₀相关(r=0.345,P=0.013),CK-MB、LDH、α-HBDH变化与 V₂₅、V₃₀均相关(r=0.465~0.376,P=0.001~0.005);三维适形放疗前后CK-MB、LDH变化与 V₃₀相关(r=0.330、0.274,P=0.014、0.033),α-HBDH变化与 V₂₅、V₃₀、V₃₅相关(r=0.270~0.331,P=0.046~0.014)。当放疗剂量>50 Gy时AST、LDH、α-HBDH变化与 V₂₅、V₃₀相关(r=0.256~0.359,P=0.019~0.006),CK-MB变化与 V₃₀相关(r=0.233,P=0.037);≤50 Gy时仅 V₅、V₄₅与CK变化相关(r=0.581、0.536,P=0.023、0.043)。结论 心脏体积剂量与三维放疗前后心肌酶水平变化有一定相关性,提示心脏DVH参数有助于评价放疗诱导的心肌损伤。

The analysis of correlation between changes of myocardial enzymes level in serum before and after radiation and dose-volume histogram parameters of the heart

Objective To analyze the correlation between the changes of myocardial enzyme level inserum before and after radiotherapy and dose-volume histogram (DVH) parameters of the heart. Methods
A total of 102 patients with 68 cases of lung cancer and 34 cases of esophageal cancer were recruited. All patients received three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT), with the radiation beams passing through the heart. Aspertate aminotransferase (AST), creatine kinase (CK), creatine kinase isozyme (CK-MB), lactate dehydrogenase (LDH), α-hydroxybutyrate dehydrogenase (α-HBDH) were determined in the serum before and after radiotherapy. All the enzyme levels before and after radiotherapy were compared through paired t-test. Independent sample t-test was conducted between sub-groups. And the dose-volume histogram (DVH) parameters of the heart were calculated (the volume percentage of heart receiving dose equal to or exceeding x Gy (Vx). The correlation
between myocardial enzyme level and DVH parameters was analyzed through Pearson method. Results
Serum AST, CK-MB, LDH, α-HBDH levels increased significantly after radiotherapy (19.42∶27.89,14.72∶19.57,178.80∶217.57,140.32∶176.25,t=－3.39－－6.92,all P=0.000). In Group IMRT, significant correlations between the increase of myocardial enzyme concentration and DVH parameters of the heart are found, AST with V₂₀, V₂₅, V₃₀ of heart (r=0.302－0.431,P=0.039－0.003), CK with V₃₀ of heart (r=0.345,P=0.013),and CK-MB, LDH, α-HBDH with V₂₅, V₃₀(r=0.465－0.376,P=0.001－0.005). In Group CRT, there are significant correlations between changes of CK-MB, LDH level and V₃₀of heart (r=0.330,0.274,P=0.014,0.033), α-HBDH and V₂₅, V₃₀, and V₃₅ of heart (r=0.270－0.331,P=0.046－0.014). When the irradiation dose was more than 50 Gy, significant correlations were found between the concentration changes of AST, LDH, α-HBDH and V₂₅, V₃₀ of heart (r=0.256－0.359,P=0.019－0.006), CK-MB and V₃₀(r=0.233,P=0.037). When the irradiation dose was 50 Gy or less, only the concentration change of serum CK has significant correlation with V₅ and V₄₅ of heart (r=0.581,0.536,P=0.023,0.043). Conclusions There exists certain correlations between changes of myocardial enzymes level before and after radiation and DVH parameters of the heart, which indicates that the DVH parameters of heart are helpful to evaluate the radiation-induced myocardial damage.