49例复发鼻咽癌的调强适形放射治疗

Intensity modulated radiation therapy for 49 patients with recurrent nasopharyngeal carcinoma

目的 评价调强适形放射治疗 (IMRT)对复发性鼻咽癌的疗效、放射反应以及对肿瘤的控制。方法 4 9例鼻咽局部复发的鼻咽癌患者 (KPS≥ 80 )均采用全程IMRT ,其中伴有颈淋巴结转移的 3例患者 (N12例 ,N31例 )在IMRT后 ,给予PDD +5 Fu方案 5～ 6个疗程化疗。结果 治疗计划结果显示 ,覆盖鼻咽GTVD95的平均剂量为 6 8.0 9Gy ,GTVV95的平均体积为 98.4 6 % ,靶区内GTV、CTV1和CTV2的平均剂量分别为 71.4 0Gy、6 3.6 3Gy和 5 9.81Gy。 4 9例患者的中位随访时间为 9个月 (3～16个月 )。局部无进展生存率 10 0 % ,IMRT结束时有 3例 (6 .1% )出现局部残留 ,14例 (2 8.6 % )出现鼻咽腔黏膜坏死。结论 IMRT能有利覆盖肿瘤靶区而使邻近敏感器官获得有效分隔 ,对复发性鼻咽癌的再程放疗不失为一种有效方法。值得注意的是高剂量的鼻咽局部IMRT治疗对于复发性鼻咽癌容易导致鼻咽黏膜坏死 ,故应适当减少GTV的处方剂量以 6 0～ 6 5Gy为宜。

Objective To evaluate the feasibility, toxicity and tumor control of intensity modulated radiation therapy (IMRT) for recurrent nasopharyngeal carcinoma. Methods Fourty nine patients (Karnofsky performance status (KPS)≥80) with local regional recurrence in the nasopharynx were treated with full course IMRT. Three patients with cervical lymph node metastasis (N1 2 and N3 1) were further supplemented with 5 to 6 courses of chemotherapy (Cisplatin + 5 Fu) after IMRT. Results The results of treatment plan showed that the mean dose of covering gross tumor volume (GTV) (D 95 ) in the nasopharynx was 68.09 Gy and the mean volume of GTV (V 95 ) receiving the 95% dose was 98.46%. The mean dose of GTV, clinical target volune CTV1 and CTV2 in the targets were 71.40 Gy, 63.63 Gy and 59.81 Gy. The median follow up time was 9 months (range 3 to 16 months). The local regional progression free survival was 100% with local regional residual disease in 3 (6.1 %) cases but was complicated with nasopharyngeal mucosa necrosis in 14 (28.6%) cases after IMRT. Conclusion Intensity modulated radiation therapy, as a re treatment option for recurrent nasopharyngeal carcinoma, is able to improve the tumor target coverage and spare the adjacent critical structures. As high dose IMRT can result in radio necrosis of nasopharyngeal mucosa, the prescription dose of GTV should be suitably decreased to 60～65 Gy. [