宫颈癌治疗后主动脉旁淋巴转移调强放疗剂量学研究及临床观察

Dosimetric comparison and clinical observation of intensity modulated radiation therapy for cervical cancer patients with para-aortic lymph node metastasis

目的：探讨调强放射治疗（intensity modulated radiotherapy，IMRT）应用于宫颈癌治疗后主动脉旁淋巴结转移的剂量学特点、治疗效果及在减少并发症方面的价值。方法：选取2005—06—01—2012—12—30临沂市肿瘤医院（65例）和山东省肿瘤医院（51例）接受全程IMRT或适形放疗（conventional radiotherapy，CRT）治疗的116例主动脉旁淋巴结转移的宫颈癌患者。56例宫颈癌治疗后主动脉旁淋巴结转移患者接受全程IMRT，给予PTV剂量（58～69）Gy／（29～30）次，2．0～2．3Gy／次，中位剂量63．5Gy，随机选择10例患者，用三维治疗计划系统进行IMRT和常规放疗（CRT）计划设计，拟给予相同的处方剂量，比较危及器官受照射剂量。随机选择同期接受CRT（60例）患者，比较IMRT和CRT的靶区剂量、疗效、急性和晚期毒副作用及生存率。结果：56例患者均完成全程IMRT，95％的等剂量曲线可以覆盖99％的PTV体积，IMRT与拟行CRT计划比较，IMRT计划中小肠（t=2．958，P=0．016）、肾脏（t=14．438，P〈0．001）和脊髓（t=34．511，P〈0．001）受照射剂量明显降低，靶区剂量明显提高，t=20．924，P〈0．001，IMRT组的急性和慢性毒副作用均明显减少，P〈0．05。两组完全缓解率（x2=11．048，P=0．001）、部分缓解率（x2=5．893，P=0．015）和总有效率（x2=32．251，P〈0．001）比较差异均有统计学意义；1、3和5年生存率比较差异有统计学意义，x2=9．530，P=0．002。结论：IMRT对宫颈癌治疗后主动脉旁淋巴结转移患者可获得理想的剂量分布，邻近危及器官得到保护，临床疗效满意，毒副作用明显减少，有效率提高，生存期明显延长。

OBJECTIVE： To investigate the dosimetry and clinical outcomes of intensity modulated radiotherapy （IMRT） versus conventional radiotherapy （CRT） for patients of cervical cancer with para-aortic lymph node metastasis after radiotherapy. METHODS： This retrospective study used dates from 116 patients completed full course of IMRT or CRT in Shandong Linyi Tumor Hospital（65 cases）and Shandong Cancer Hospital（51cases）from June 1,2005 to December 30,2012. All 56 patients completed full course of IMRT, 2.0 to 2.3 Gy/fraction to the PTV. The total dose was 58~ 69 Gy and the median dose was 63.5 Gy. Simultaneously conventional para-aortic lymph node radiation plan was designed for 10 patients with the same prescription dose. The dose of organs at risk were compared. Sixty cases received CRT with para-aortic lymph node metastasis after radiotherapy were chosen to compare the target dose, efficacy, acute and chronic toxicity as well as survival rate with the 56 IMRT cases. RESULTS： In the IMRT group, 95% of iso-dose curve covered more than 99% PTV. IMRT plans compared with CRT plans, the dose of small intestine（t= 2. 958, P= 0. 016）, kidney （t = 14. 438, P〈0. 001）, spinal（t= 34.511, P〈 0. 001 ） were significantly lower. Compared with CRT, target dose of IM- RT was significantly increased（t= 20. 924, P〈0. 001）. The acute and chronic toxicity of IMRT was significantly decreased （P〈0. 05）. The complete remission rate（X2 = 11. 048, P= 0. 001）, partial remission rate （X2 = 5. 893, P = 0. 015） and o- verall response rate（X2= 32.251, P〈0.001） were significantly increased. The survival rates of 1,3,5-year had significant difference（x2 = 9. 530,P=0. 002）. CONCLUSIONS.. IMRT therapy makes better dose distribution than CRT for cervical cancer patients with para-aortic lymph node metastasis after radiotherapy, target area can obtain radical dose. The adjacent organs at risk can be protected well. IMRT has satisfying efficacy and tolerable toxicities. Overall response rate and surviv- al rate are significantly higher.