头颈部肿瘤放疗后甲状腺损伤危险因素分析

Risk factors for prediction of thyroid injury after radiotherapy in head/neck tumors

摘要:

目的 研究头颈部肿瘤患者放疗后甲状腺损伤的危险因素。方法 选取该院58 例接受调强放射治 疗（IMRT）的头颈部肿瘤患者作为研究对象，记录放疗、随访期间甲状腺发生损伤和治疗情况，分析患者的年 龄、性别及肿瘤分型分期等基线资料以及甲状腺受照剂量、体积参数等临床治疗相关指标与甲状腺损伤的关系。 采用Logistic 多因素分析影响头部肿瘤患者放疗后甲状腺损伤的独立影响因子，利用ROC 分析独立影响因子对 预测甲状腺损伤的应用价值。结果 平均随访时间17.50 个月，死亡5 例；共发生甲状腺损伤27 例，发生率 46.55%。其中，甲状腺功能减退23 例，甲状腺功能亢进症（甲亢）4 例，发生甲亢的患者原发肿瘤均为霍奇金淋 巴瘤。Logistic 多因素分析显示年龄、平均受照剂量（MTD）及V40 是影响放疗后甲状腺损伤的独立因素（R=0.116、 5.894 及9.375，P =0.000、0.000 及0.003）。年龄、MTD 及V40 预测头颈部肿瘤放疗后甲状腺损伤的曲线下面积 （AUC）分别为0.596、0.741 及0.714 ；敏感性分别为0.516、0.741 及0.926 ；特异性分别为0.815、0.645 及 0.548 ；最佳截断值分别为39.5 岁、45.5Gy 及69.5%。放疗导致的甲状腺功能减退和亢进患者间年龄、MTD 及 V40 水平无差异（P >0.05）。结论 甲状腺MTD 和V40 是头颈部肿瘤放疗后甲状腺损伤的高危因素。当MTD 超 过45.5 Gy，V40<69.5%，将增加甲状腺损伤风险，甲状腺损伤以甲状腺功能减退症为主。另外，高龄是发生甲状 腺功能减退的保护因素，甲状腺受照剂量、V40 及患者年龄对放疗诱发的甲状腺损伤具有较高预测价值，但上 述因素对判断甲状腺损伤类型的价值有限。

Abstract:

Objective To investigate the risk factors of thyroid injury after radiotherapy in patients with head/ neck cancer. Methods Totally 58 patients with head/neck cancer who received intensity-modulated radiation therapy (IMRT) in our hospital were included in this study. The occurrence of thyroid injury during radiotherapy and followup was recorded, along with information including age, gender, tumor type, stage, thyroid radiation dose and volume parameter. Logistic multivariate analysis was performed to screen the independent factors to predict the thyroid injury. Results The mean follow-up time was 17.50 months; 5 cases died and 27 cases experienced thyroid injury (27/58, 46.55%). Twenty-three cases had hypothyroidism, while the other 4 cases were hyperthyroidism who were all diagnosed with Hodgkin's lymphoma. The Logistic multivariate analysis showed that age, MTD and V40 were the independent factors (R=0.116, 5.894, 9.375, P = 0.000, respectively). AUC of Age, MTD, and V40 were 0.596, 0.741 and 0.714, respectively. Sensitivities of age, MTD and V40 were 0.516, 0.741 and 0.926, respectively. Specificity of Age, MTD, and V40 were 0.815, 0.645 and 0.548, respectively. The best cut-off value of Age, MTD and V40 were 39.5, 45.5 Gy and 69.5%, respectively. Conclusion MTD and V40 are the risk factors while age is a protective factor for thyroid injury after radiotherapy in head/neck tumors. MTD exceeding 45.5 Gy and V40 over 69.5% indicates high chance of thyroid damage.