鼻咽癌调强放疗疗效及局部复发的剂量学因素分析

Clinical Outcomes and Dose-volume Analysis of Local Recurrence after Intensitymodulated Radiation Therapy for Nasopharyngeal Carcinoma Patients

目的研究鼻咽癌调强放疗计划的剂量分布,重点分析复发患者调强放疗计划的剂量学特点,以评价治疗计划的合理性。方法回顾性分析339例经病理确诊的初治鼻咽癌(NPC)患者的调强放疗(IMRT)计划,并对12例局部治疗失败患者进行剂量学分析。结果全组1年局部控制率、区域控制率分别为98.1%、99.3%;全组2年局部控制率、区域控制率分别为96.5%、98.5%。共有12例局部治疗失败,且均为野内复发。结论目前的鼻咽癌调强放疗计划能够取得较好的局部控制率,靶区覆盖情况好,同时有效保护了邻近危机器官。野内复发提示更小范围的合理化靶区设置和原发肿瘤局部加量照射有望进一步提高局部控制率。

Objective To evaluate the reasonability of treatment plan by analyzing the dose distribution of intensity-modulated radiation therapy plan for nasopharyngeal carcinoma(NPC) patients, especially for the recurrent NPC. Methods The intensity modulated radiation therapy(IMRT) for 339 patients with biopsyproven and newly diagnosed NPC were analyzed retrospectively, and 12 cases with locally recurrent NPC were performed in dosimetric analysis. Results The 1-year local control rate and regional control rate of the whole group were 98.1% and 99.3%, respectively. And the 2-year local control rate and regional control rate were 96.5% and 98.5%, respectively. Local treatments for 12 patients were failures and all the recurrent tumor volume were in fi eld. Conclusion With IMRT, excellent local control rates and tumor coverage are achieved, and adjacent organs at risk are protected well. Recurrent tumors volume in fi eld suggest that smaller target volume defi nition and increasing dose for local primary tumor would improve local control rate.