调强放射治疗在宫颈癌治疗中的临床研究

Clinical Study of Intensity Modulated Radiation Therapy for Patients with Cervical Cancer

目的:探讨中晚期宫颈癌患者应用调强放射治疗(IMRT)技术在提高靶区剂量与减少正常组织受量方面的价值。方法:40例中晚期宫颈癌患者均给予全程IMRT1.8～2.2Gy/次,每周4次外照射和1次内照射,外照射的处方剂量为50～55Gy,中位剂量为53.5Gy,内照射共给6次,每次5Gy。同时拟设计该40例患者2野和4野的放疗计划,拟给予相同的处方剂量,比较危险器官(OAR)直肠、小肠、膀胱和骨髓的受照射剂量和体积。结果:40例患者均完成全程的IMRT,放射治疗计划靶区(PTV)的平均剂量为54.5Gy,90%的等剂量曲线(中位剂量53.5Gy)可以覆盖99%以上的肉眼靶区(GTV)体积。IMRT与普通2野和4野放疗组比较,小肠、直肠、膀胱和骨髓的受照射剂量和体积均明显减少(P<0.05)。急慢性放射反应明显减轻。1,2年生存率比较,差异无统计学意义。结论:IMRT放疗技术可以使患者的放疗靶区获得较为理想的剂量分布,邻近危险器官得到很好的保护,从而减小了急慢性放疗反应,毒副反应可以耐受,但未能提高近期生存率。

Objective： To investigate the application value of intensity-modulated radiation therapy（IMRT） for cervical cancer patients to improve the prescription dose of target volume and with minimizing complication. Methods： 40 cervical cancer patients received full course IMRT 1.8 to 2.0 Gy/fraction, four fractions per week, and one fraction per week of inner radiotherapy. The total dose was from 50 to 55Gy, and the median dose was 53.5Gy. Each patient received 6 inner radiotherapy fractions, 5Gy per fraction. Simultaneously conventional 2-field and 4-field plans were designed for the same 40 patients with the same prescription dose. The dose and the volume delivered to the organ at risk （OAR） was compared. The OAR included rectum, small intestine, bladder and bone marrow. Results： All the patients completed the full course of IMRT. The average dose delivered to the planning target volume （PTV） was 54. 5Gy, and 90% ofisodose curve （median dose 53.5Gy） covered more than 99% gross tumor volume （GTV）. The dose delivered to small intestine, rectum, bladder, bone marrow was significantly lower than that of conventional 2-field and 4-field plans （P〈0.05）. The acute and chronic toxicity oflMR T was significantly decreased. However, the survival rates of one or two year were not significantly different. Conclusion： IMRT therapy makes better dose distribution, GTV receives radical dose and the adjacent OAR gets better protection. IMRT has satisfying short-term efficacy and tolerable toxicities, but not improve the survival rate of near future.