鼻咽癌外照射加腔内近距离超分割推量照射的远期疗效分析

Long-term Efficacy of External Radiotherapy Plus Intracavitary Hyperfractionated Brachytherapy on Nasopharyngeal Carcinoma

背景与目的:鼻咽癌的后装治疗一般采用鼻咽腔内治疗的方法进行推量照射,适用于局部早期鼻咽癌。福建省肿瘤医院率先开展鼻咽旁插植技术,无颅底破坏的局部晚期鼻咽癌采用后装治疗推量照射。本文分析腔内后装推量照射的远期疗效,探讨常规外照射的合适剂量配合后程超分割后装推量照射的临床价值。方法:1998年1月～2002年12月体外照射加腔内后装超分割推量放射治疗鼻咽癌患者352例,体外常规放射治疗50～70Gy后进行腔内近距离超分割推量照射,外照射后咽旁间隙肿瘤残留者配合咽旁区插植放疗。采用个体化鼻咽腔内施源器,超分割照射每次2.5～3.0Gy,2次/天,间隔6h,总剂量5～32Gy,中位剂量17Gy。结果:本组1、2、3、5年生存率分别为97.0%、91.3%、87.6%、84.7%。总体5年生存率Ⅰ、Ⅱ期88.2%,Ⅲ、Ⅳ期79.2%(log-rank检验,P=0.016);总体局控率Ⅰ、Ⅱ期94.1%,Ⅲ、Ⅳ期91.7%(log-rank检验,P>0.05)。后组颅神经损伤32例(9.4%)。结论:鼻咽腔内后装联合咽旁间隙插植近距离放射治疗鼻咽癌取得良好的局控率和生存率,局部晚期鼻咽癌取得与早期鼻咽癌类似的局控率,咽旁间隙受累者咽旁插植增加颈动脉鞘区照射剂量,后组颅神经损伤发生率较高。

BACKGROUND ＆ OBJECTIVE. Intracavitary hyperfractionated brachytherapy is one of the main methods in brachytherapy for early stage nasopharyngeal carcinoma （NPC）. We developed the parapharyngeal space interstitial brachytherapy for the NPC patients with residual tumor in the parapharyngeal space after external radiotherapy, and used hyperfractionated brachytherapy as a boosting radiation for the locally advanced patients who have no tumor invasion in the base of skull. This study was to analyze the long-term efficacy of external radiotherapy plus intracavitary hyperfractionated brachytherapy on NPC, and explore the clinical value and suitable dose. METHODS. From Jan. 1998 to Dec. 2002, 352 NPC patients were treated by external radiotherapy plus intracavitary hyperfractionated brachytherapy in Fujian Provincial Tumor Hospital. The parapharyngeal space interstitial brachytherapy was used in the patients with residual tumor in the parapharyngeal space after external radiotherapy. The external irradiation dose varied from 50 to 70 Gy. Brachytherapy was delivered by 2.5-3.0 Gy per fraction, and 2 fractions per day with an interval of 6 h ; the total dose ranged from 5 to 32 Gy with a median of 17 Gy. RESULTS. The overall 1-, 2-, 3-, and 5-year disease-free survival rates were 97.0%, 91.3%, 87.6%, and 84.7%, respectively. The 5-year survival rate was significantly higher in stage Ⅰ- Ⅱ patients than in stage Ⅲ-Ⅳ patients （88.2% vs. 79.2%, P= 0.016）; but the local control rate was similar in the 2 groups （94.1% vs. 91.7%）. Thirty-two （9.4%） patients had radiation injury at the lower cranial nerve. CONCLUSION. External radiotherapy plus intracavitary and interstitial hyperfractionated brachytherapy can improve local control rate and survival rate of NPC, but the occurrence rate of radiation injury at the lower cranial nerve is higher in the patients with parapharyngeal space involvement than in other patients.