左侧乳腺癌术后逆向调强放疗引起放射性心脏损伤的临床研究

Clinical study on radiation-induced heart disease caused by inverse intensity modulated radiotherapy in postoperative left-sided breast cancer patients

目的研究临床、物理因素对左侧乳腺癌术后逆向调强放疗后放射性心脏损伤(RIHD)发生的影响。方法对32例左乳腺癌术后患者采用逆向调强放疗,所有患者分别在放疗前、放疗中(30Gy时)、放疗结束时和放疗结束后1个月及3个月检测心电图和血清肌钙蛋白I(c Tn I)。应用NCI-CTCAE 3.0版对急性放射性心脏分级标准评价。采用单因素分析临床、物理因素与心脏损伤的关系。结果放疗结束3月未检测出c Tn I异常。随着心脏受照射量的增加,血清c Tn I含量随之升高,放疗剂量达DT 30Gy时血清c Tn I含量较放疗前升高,差异有显著性(t=2.476,P<0.05);放疗结束时与放疗前的比较,血清c Tn I含量显著升高(t=9.834,P<0.001),放疗后1个月与放疗前比较,c Tn I含量仍有轻度升高,差异有统计学意义(t=2.865,P<0.05);放疗后3个月与放疗前比较,显示血清c Tn I含量变化无统计学差异(t=0.284,P>0.05)。无心脏损伤组和有心脏损组年龄、KPS评分、病理类型、ER表达情况、PR表达情况、Her-2表达情况均无显著性差异(χ2值分别为1.91、0.36、1.54、0.68、2.50、0.10,均P>0.05),无心脏损伤组心脏Dmax、心脏V30均显著低于有心脏损伤组(t值分别为2.29、3.34,均P<0.05),而两组心脏Dmin、心脏Dmean、心脏V40均无显著性差异(t值分别为1.89、1.68、1.56,均P>0.05)。结论乳腺癌逆向调强放疗后心脏的损伤以心电图异常较为常见,其中心脏Dmax、V30是放射性心脏损伤发生的影响因素。血清中c Tn I的变化可早期反映放射性心脏损伤,以利于尽早预防和治疗放疗并发症和后遗症。

Objective To study the influence of clinical and physical factors on radiation-induced heart disease （RIHD） caused by inverse intensity-modulated radiotherapy in postoperative left-sided breast cancer patients. Methods A total of 32 postoperative left-sided breast cancer patients received inverse intensity modulated radiotherapy. Electrocardiogram （ECG） and eTnI of all patients were detected before their receiving of radiotherapy, during the radiotherapy （30 Gy）, at the end of radiotherapy, 1 month and 3 months after radiotherapy, respectively. Acute RIHD was classified by NCI-CTCAE 3.0 version. Univariate analysis was carried out to analyze the relations between clinical and physical factors with heart damage. Results No cTnI abnormality was identified in 3 months after radiotherapy. With the increase of irradiated heart volumes, the level of serum eTnI increased. When the radiation dose reached DT 30Gy, an increase in the level of serum cTnI was identified compared with the situation before radiotherapy. The difference was of statistical significance （ t = 2. 476, P 〈 0.05 ）. A remarkable increase in the concentration of cTnI in serum at the end of radiotherapy was noted when compared to that before radiotherapy （t = 9. 834, P 〈0. 001 ）. A slight increase in serum eTnI level was found in 1 month after radiotherapy when compared with the situation before radiotherapy. The difference was statistically significant （ t = 2. 865, P 〈 0. 05 ）. No statistically significant difference was detected in serum eTnI level in 3 months after radiotherapy and before radiotherapy （ t = 0. 284, P 〉 0.05 ）. No remarkable difference was noticed between patients without heart damage and patients with heart damage in age, KPS score, pathological type, expression of ER and PR as well as Her-2 （X2 value was 1.91, 0.36, 1.54, 0.68, 2.50, and 0. 10, respectively, all P 〉 0.05 ）. Patients without heart damage had significantly lower heart Dmax and heart V30 than patients with heart damage （ t value was 2.29, and 3.34, respectively, both P 〈 0.05）. However, there was no significant difference between them in heart Dmin, Dmean and V40 （t value was 1.89, 1.68, and 1.56, respectively, all P 〉 0.05 ）. Conclusion Abnormal electrocardiogram is commonly seen in left-sided breast cancer patients with heart damage after inverse intensity-modulated radiotherapy. Heart Dmax and V30 are the influencing factors for RIHD. The change of cTnI concentration in blood serum can serve as a reference to discover radioactive myocardial damage at early stage, which is beneficial to the early prevention and treatment of complications and sequelae of radiotherapy.