28例宫颈癌放疗后主动脉旁淋巴结转移的调强放射治疗

Intensity modulated radiation therapy for 28 cervical cancer patients with paraaortic lymphnode metastasis

目的:探讨调强放射治疗(intensity modulated radiation therapy,IMRT)用于宫颈癌放疗后主动脉旁淋巴结转移患者的治疗效果、减少并发症的价值。方法:28例宫颈癌放疗后主动脉旁淋巴结转移患者(KPS≥70)放疗前均行1～3个周期化疗,然后给予全程IMRT,1,8～2．3Gy/次,1次/日,5次/周,总处方剂量58～68Gy,中位剂量63．5Gy,同时设计28例患者的普通主动脉旁2野照射计划,拟给予相同的处方剂量,比较危险器官(organs at risk,OAR)受照射剂量。随机选择32例接受普通放疗的病例,比较IMRT和普通放疗的急慢性毒副反应及近期疗效。结果:28例患者均完成全程IMRT,照射靶区内计划靶区体积(planning target volume,PTV)的平均剂量为67．5Gy,90%的等剂量曲线(中位剂量63．5Gy)可以覆盖99%以上的肉眼肿瘤靶区体积(gross tumor volume,GTV)。IMRT与普通主动脉旁两野比较,肾、脊髓、小肠的受照射剂量明显减小(P均＜0．05),急、慢性毒副反应明显减少。两组完全缓解率和有效率比较均有统计学意义(P＜0．05)。1、2年生存率IMRT组较普通放疗组明显提高(P＜0．05),但3年生存率比较无统计学意义(P＞0．05)。结论:IMRT技术用于治疗宫颈癌放疗后主动脉旁淋巴结转移,可获得理想的剂量分布,靶区可以获得根治性剂量,临近危险器官得到很好的保护,临床近期疗效满意,毒副反应可以耐受。

Objective： To investigate the significence of intensity modulated radiation therapy （IMRT） for cervical cancer patients with paraaortic lymph node metastasis to maximize tumor control with minimizing complications. Methods： Twenty eight cervical cancer patients with paraaortic lymph node metastasis after radiotherapy were selected whose Karnofsky performance status（KPS）≥70. They received full course IMRT after 1 to 3 cycles of chemotherapy. The prescription dose was 1.8 to 2.3Gy/ fraction, once daily, 5 fractions per week. The total dose was from 58.0-68.0 Gy and the median dose was 63.5 Gy. Simultaneously conventional paraaortic lymph node radiation plan（2-field plan） was designed for the 28 patients with the same prescription dose. The dose delivered to the organs at risk （OAR） was compared. Thirty-two cases with paraaortic lymph node metastasis were randomly selected and given conventional radiotherapy. The acute and chronic toxicities and short-term efficacy of IMRT and conventional radiotherapy were compared. Results： All the 28 patients completed the full course of IMRT. The average dose delivered to the planning target volume （PTV） was 67.5 Gy, and 90% of iso-dose curve （median dose of 63.5 Gy） covered more than 99 % gross tumor volume （GTV）. The doses delivered to small intestine, kidney and spinal cord were significantly lower by IMRT than conventional 2-field plans （P〈0.05）. Compared with conventional radiotherapy the acute and chronic toxicity of IMRT was significantly decreased. The complete response rate and overall response rate （complete response＋partial response） had significant difference between the two groups （P〈0.05）. One- and two-year survival rate were significantly higher in IMRT group than conventional radiotherapy group （P〈0.05）. But the difference in the 3-year survival rate between the two groups was not significant （P〉0.05）. Conclusion： Compared with conventional radiotherapy for paraaortic lymph node metastasis of cervical cancer, IMRT achieved a better dose distribution. The tumor target volume receives radical dose and the adjacent organs at risk gets better protection. IMRT has statisfying short-term efficacy and tolerable toxicities.