直肠癌术后盆腔放疗方式及剂量对骨髓功能的影响

目的?探讨术后盆腔不同放疗方式及剂量对直肠癌患者骨髓造血功能的影响。方法?选择广东中山市人民医院肿瘤中心放疗三区2015年6月至2017年6月216例直肠癌术后患者作为研究对象，按放疗方式不同分为3组，各72例，分别采用常规二维放疗 （2DRT）、三野三维适形照射（3D-CRT）^1]和调强放射（IMRT）治疗。比较3种放疗方式在直肠癌术后辅助治疗中对患者骨髓造血功能的影响，明确骨髓抑制发生的相关危险因素。结果?2D-CRT组、3D-CRT组和IMRT组靶区平均剂量和剂量不均形指数比较，差异无统计学意义（P>0.05）；IMRT组靶区适形指数高于2D-CRT组和3D-CRT组，3D-CRT组区适形指数高于2D-CRT组（P<0.05）。3组患者0~Ⅳ级骨髓抑制分布比较差异无统计学意义（P<0.05）；但IMRT组Ⅱ~Ⅳ级骨髓抑制高于2D-CRT组和3D-CRT组（P<0.05）。单因素分析结果显示：放疗方式、髂骨V₃₀、髂骨V₄₀等影响骨髓抑制（P<0.05），logistic分析显示，放疗方式和髂骨V₃₀是Ⅱ~Ⅳ级骨髓抑制发生独立危险因素（P<0.05）。结论?IMRT靶区适形度优于2D-CRT和3D-CRT，但其骨髓抑制严重程度高于其他两种放疗方式。IMRT和髂骨V₃₀是直肠癌术后盆腔放疗Ⅱ~Ⅳ级骨髓抑制的独立危险因素。

Effect of pelvic radiation therapy and dosage on bone marrow function after rectal cancer operation

Abstract] Objective: To investigate the effect of different postoperative pelvic radiotherapy modalities and doses on bone marrow hematopoietic function in patients with rectal cancer. Methods: 216 cases of postoperative rectal cancer patients in our hospital from June 2015 to June 2017 were selected as the research object and randomly divided into 3 groups, 72 cases in each group. The three groops were given 2D-CRT, three dimensional conformal radiotherapy (3D-CRT), intensity modulated radiotherapy (IMRT), respectively. The effects of three different radiotherapy modalities on the hematopoietic function of the patients after rectal cancer surgery were compared, and the related risk factors of bone marrow suppression were clarified. Results: There was no significant difference between the three groups in target dose and HI (P>0.05). The CI in group IMRT was significantly higher than that in group 2D-CRT and group 3D-CRT, and the CI in group 3D-CRT was significantly higher than that in group 2D-CRT (P<0.05). There was no significant difference in the grade 0~Ⅳ bone marrow suppression between the three groups (P<0.05), but the proportion of grade Ⅱ~Ⅳ bone marrow suppression in group IMRT was significantly higher than that in group 2D-CRT and group 3D-CRT (P<0.05).. The results of univariate analysis showed that radiotherapy, V30 and V40 of iliac bone had a significant effect on bone marrow suppression (P<0.05). Logistic analysis showed that there was a significant correlation between the mode of radiotherapy and V30 of iliac bone and bone marrow suppression of grade II ~ IV (P<0.05). Conclusion: The CI of IMRT is better than that of 2D-CRT and 3D-CRT, but the severity of bone marrow suppression is higher than the other two methods. Pelvic radiotherapy,bone marrow suppression, radiotherapy modality and V30 of iliac bone were significantly related to rectal cancer after operation.