鼻咽旁区插植配合体外放射治疗鼻咽癌

目的探讨鼻咽旁区插植近距离放射治疗技术在鼻咽癌治疗中的作用。方法初治鼻咽癌患者体外照射56～70Gy（T2期56～60Gy,T3期66～70Gy）后复查CT或MRI发现鼻咽旁区残留病例67例，以腔内+鼻咽旁区插植放射治疗增量，咽旁区在模拟机引导下插入1～4根施源管，采用荷兰核通公司生产的192Ir高剂量率近距离治疗机，放射剂量2.5～4.0Gy/次,2次/d，间隔>6h，总剂量12～20Gy，3～4?d完成。插植组与同期的类似病例（67例）配对进行研究。结果鼻咽旁区插植组和对照组的3年生存率分别为92.4%，84.5%（P>0.05);3年无局部复发生存率分别为97.0%、76.4%（P<0.05);3年无远地转移生存率分别为76.6%、69.1%（P>0.05)。鼻咽旁区插植组的晚期放射反应如口干、张口困难发生率均低于对照组。结论鼻咽旁区插植放射治疗可以显著提高鼻咽癌咽旁区残留的局部控制率，拓宽了鼻咽癌近距离放射治疗的适应证，是一种有效的补充治疗手段。

Study on interstitial brachytherapy combined with external beam radiation for nasopharyngeal carcinoma patients residual with involvement of the parapharyngeal space

Objective　To evaluated the role of parapharyngeal space interstitial brachytherapy (DSIBT) in the treatment of primary nasopharyngeal carcinoma (NPC).　Methods　A new brachytherapy techinque was practised in our clinic. Catheters, under the guidance of simulator fluoroscopy,were inserted from the submaxillary region into the parapharyngeal space involved to give a boost complement to conventional external beam radiation. Froma April 1996 to June 1998,67 patients with T2-3 NPC were treated by PSIBT. They all had residual lesion left in the parapharyngeal space as confirmed by CT or MRI after a standard dose of 56～70 Gy initially delivered. With 1～4 implanted catheters. an additional dose of 12～20 Gy/6～8 fractions/3～4 days was completed by afterloading of high dose rate 192　Ir wires. Another 67 patients with similar dose treated during the same period were selected as control. They received external beam radiotherapy alone to a total dose of 70～83 Gy. 　Results　No serious complications or late sequelae occurred in the PSIBT group. The overall 3-year survival rates were 92.4% and 84.5% for the PSIBT group and control group, respectively (P>0.05); the 3-year distant metastasis-free survivals were 76.6% and 69.1% (P>0.05); and the 3-year local relapse-free survivals were 97.0% and 76.4%,respctively. Statistical significance was reached by the last difference (P<0.05). 　Conclusion　Parapharyngeal space interstitial brachytherapy is of benefit to improve the local control of primary lession of NPC with residual parapharyngeal space involvement. It is a safe and effective approach to boost the local irradiation dose. More extensive practices should be contemplated for definite conclusion.