初治鼻咽癌调强适形放疗的疗效分析

Analysis of intensity-modulated radiotherapy for untreated patients with nasopharyngeal carcinoma

目的探讨根治性调强适形放疗（IMRT）治疗初治鼻咽癌的临床疗效及毒副反应。方法74例鼻咽癌患者均接受全程IMRT照射，给予鼻咽大体肿瘤体积（GTVnx）处方剂量69．9Gy／30f，颈部转移淋巴结（GTVnd）69．9Gy／30f，临床靶体积1（CTV1）60Gy／30f，临床靶体积2（CTV2）54Gy／30f。按照RTOG／EORTC标准评价急性反应和晚期放射损伤；采用Kap—lan．Meier法进行生存分析。结果中位随访时问为39个月（13—80个月）。全组1、2、3、5年生存率分别为97．3％、93．8％、88．2％和77．2％，无远处转移生存率分别为93．2％、91．1％、91．1％和84．1％，局部区域控制率分别为98．6％、91．0％、86．8％和80．6％。不同临床分期和T分期患者的生存率差异均无统计学意义（P〉0．05），而不同N分期患者的生存率差异有统计学意义（P=0．02）。在治疗失败的12例患者中，局部和区域失败分别占治疗失败病例的50．0％和16．7％，远处转移占58．3％。74例患者中3例出现3级口干，1例出现放射性颞叶损伤，4例出现3级张口困难，全组未发现颅神经损伤病例。结论采用GTV照射剂量69．9Gy／30fIMRT治疗初诊时无远处转移的鼻咽癌远期疗效较好，毒副反应少，N分期是其预后的影响因素。

Objective To investigate the clinical effects and toxicity of intensity-modulated radiotherapy（IMRT） for untreat- ed nasopharyngeal carcinoma（ NPC ） patients. Methods Seventy-four NPC patients receiving IMRT were enrolled from January 2005 to April 2011. The prescription dose was given 69.9 Gy/30f to the nasophaxynx gross tumor volume（GTVnx） , 69.9Gy/30f to positive neck lymph nodes（ GTVnd）, 60Gy/30f to the first clinical target volume （ CTV1 ） and 54Gy/30f to the second clinical target volume （CTV2）. The acute and late radiation injury were evaluated according to RTOG/EORTC criteria. Kaplan-Meicr method was used to calculate the overall survival rate（ OS）, distant metastasis-free survival rates（DMFS） and loco-regional control rates from the last day of therapy. Results The median follow-up time was 39 months（range 13 to 80）. The 1-,2-,3- and 5-year survival rates were 97. 3% ,93.8% ,88.2% and 77. 2% respectively; I-, 2-, 3- and 5-year DMFS were 93.2% ,91.1% ,91. I% and 84. 1% and the 1-, 2-, 3- and 5-year loeo-regional control rates were 98.6% ,91.0% ,86. 8% and 80. 6% ,respectively. The statistically significant differ- ence in OS was found in different N stage（P 〈0. 05） , rather than for both clinical stage and T stage （P 〉0. 05）. Out of 12 failure pa- tients, there were 6 with recurrence at the primary site（50. 0% ）, 2 patients in the neck（ 16. 7% ） ,and 7 patients（58.3% ） by distant metastases. Among the 74 cases,3 cases had grade 3 xerostomia, one case had radio encephalopathy, four cases had grade 3 trismus. No patients suffered cranial nerves palsy. Conclusion The IMRT technique with the prescription dose of 69. 9 Gy/30f to GTV pro- vides favorable long-term effects with acceptable toxicity in NPC patients without distant metastasis. N stage is a prognostic factor for NPC patients.