宫颈癌调强放疗中骨盆剂量体积参数与急性骨髓抑制的关系

Association between Pelvic Dosimetric Parameters and Acute Bone Marrow Suppression in Cervical Cancer Patients Receiving Intensity Modulated Radiation Therapy

目的探讨宫颈癌行调强放疗患者骨盆剂量体积参数与急性骨髓抑制的相关性,为临床宫颈癌患者放疗计划的制定提供参考依据。方法回顾性分析我院接受单纯放疗或同步放化疗的宫颈癌患者210例,在放疗计划系统中勾画患者的骨盆,应用X^2检验、t检验和logistic回归多因素统计学方法,分析宫颈癌放疗患者骨盆剂量体积参数V与急性骨髓抑制的关系。结果210例患者≥2级急性骨髓抑制发生率为82. 86%(174/210);其中行同步化疗患者三2级急性骨髓抑制的发生率为91.38%(106/116),明显高于仅行单纯放疗患者的72. 34%(68/94)(P=0.00)。94例行单纯放疗的患者中,≥2级急性骨髓抑制患者的骨盆 V10 ,V20、V30高于<2 级急性骨髓抑制患者(t =-2. 03、- 3. 237、- 2. 626 ,P = 0. 045、0. 002、0. 010),Logistic回归分析发现,骨盆V20与≥2级骨髓抑制的发生有显著相关性(OR=5.285,P=0.012);116例行同步放化疗患者的骨盆剂量体积参数对≥2级急性骨髓抑制发生率的影响未见明显差异(P >0.05)。受试者工作(ROC)曲线确定骨盆V20的阈值为84%。结论骨盆V20是宫颈癌患者放疗过程中发生≥2级骨髓抑制的相关因素,将骨盆V20限制在84%以下,可在一定程度上控制≥2级急性骨髓抑制的发生。

Objective To identify association between pelvic dosimetric parameters and acute bone marrow suppression in intensity modulated radiation therapy(IMRT) for cervical cancer, and provide references for clinical radiotherapy planning. Methods 210 patients receiving IMRT for cervical cancer were enrolled in this study. The pelvic was contoured for each patient in radiotherapy treatment planning system. The pelvic dose - volume parameters including V10 , V20 , V30 ,V40,V45 and V50were analyzed using univariate analysis( Chi - Square and test) and multivariate analysis ( Logistic regression model). Results The percentage of patients that developed acute bone marrow suppression (≥grade 2) was 82. 86%(174/210). Compared to patients undergoing radiotherapy alone,patients received concurrent chemotherapy were more likely to develop acute bone marrow suppression( Mgrade 2). The univariate analysis revealed that pelvic V10 , V20 and V30 of 94 patients received radiotherapy alone with (≥grade 2 acute bone marrow suppression were higher than those < grade 2 patients(t =-2.03,-3. 237 ,-2. 626,P =0. 045 ,0. 002,0. 010). Multivariate analysis demonstrated that V20 was the independent factor affecting (≥grade 2 bone marrow suppression( OR = 5. 285 ,P =0. 012). There was no significant difference on effects of pelvic dosimetric parameters and Mgrade 2 acute bone marrow suppression(P > 0. 05 ). The threshold of pelvic V20 was 84% as determined by receiver operating curve (ROC). Conclusion There is a correlation between pelvic V20 and ≥grade 2 acute bone marrow suppression. To better predict and control ≥ grade 2 acute bone marrow suppression, pelvic V20 should be carefully controlled below 84% in the treatment plan for cervical cancer patients.