基于Logistic、ROC分析直肠癌放化疗导致急性骨髓抑制的物理因素分析

Factors affecting acute myelosuppression induced by radiotherapy and chemotherapy for rectal cancer

目的研究直肠癌患者临床同步放化疗导致急性骨髓抑制的影响因素分析.方法选取2016-06/2017-06在我院行放化疗同步治疗的直肠癌患者纳入64例,应用单因素和Logistic回归分析直肠癌患者的骨盆剂量参数和≥2级急性骨髓抑制的关系,并在放疗系统中勾画出64例患者的骨盆,分别为骨盆下部、骶骨、髂骨等3部分.临床因素包括:临床分期、放疗方法、化疗方案、年龄、性别及原始色素水平;骨盆剂量体积参数包括:骨盆下部、骶骨、髂骨和骨盆V5、V10、V15、V20、V25、V30、V35、V40、V45、V50及平均剂量Dmean、最大剂量Dmax.结果64例同步放化疗患者引发急性骨髓抑制的有40例(62.5%).单因素分析表明,化疗方案、性别、髂骨V20、V30和腰骶骨V45是引发急性骨髓抑制的主要相关因素.Logistic回归分析显示髂骨V30和化疗方案是造成急性骨髓抑制的主要危险因素.应用受试者工作曲线确定髂骨V30界值为46%.结论髂骨V30属于急性骨髓抑制发生的独立危险因素,在结直肠癌治疗中应考虑患者肿瘤局部的控制率和急性骨髓抑制之间的关系,制定的化疗方案应将髂骨V30控制在46%以下,从而可有效降低急性骨髓抑制的发生率.

AIM To identify the factors influencing acute myelosuppression induced by radiotherapy and chemotherapy in patients with rectal cancer.METHODS From June 2016 to June 2017,64 rectal cancer patients who underwent synchronous radiotherapy and chemotherapy at our hospital were included.Univariate and Logistic regression analyses were performed to analyze the relationship between pelvic dose parameters and grade 2 acute bone marrow suppression.Three parts of the pelvis,including the lower pelvis,sacrum,and ilium were delineated in the radiotherapy system.Clinical factors analyzed included clinical stage,radiotherapy and chemotherapy,age,gender,and original pigment level.Pelvic dose volume parameters included lower pelvic,sacral,iliac,and pelvic V5,V10,V15,V20,V25,V30,V35,V40,V45,and V50,the average dose（Dmean）,and the maximum dose（Dmax）.RESULTS There were 40（62.5%）cases of acute myelosuppression in the 64 included patients.Univariate analysis showed that chemotherapy,sex,iliac V20 and V30,and lumbosacral V45 were the main factors associated with acute myelosuppression.Logistic regression analysis showed that iliac V30 and chemotherapy were the main risk factors for acute myelosuppression.Receiver operating characteristic（ROC）analysis showed that the threshold of iliac V30 was 46%.CONCLUSION Iliac V30 is an independent risk factor for acute myelosuppression induced by radiotherapy and chemotherapy in patients with rectal cancer.In the treatment of colorectal cancer,the relationship between the local control rate and acute bone marrow suppression should be considered,and iliac V30 should be controlled to 〈 46% when formulating chemotherapy plan,which can effectively reduce the incidence rate of acute bone marrow suppression.