摘要
目的通过比较鼻咽癌单纯放射治疗后局部复发部位和首次放射治疗照射野的关系,探讨鼻咽癌放疗后复发规律。方法复发患者进行CT扫描后,将图像传输至CT模拟工作站,勾画复发病灶,并“模拟”出首次治疗的照射野,计算剂量分布和制作复发病灶的剂量体积直方图(dosevolumehistogram,DVH)。以95%等剂量曲线包绕的复发肿瘤体积(V95)判断复发与首次治疗照射野的关系:95%以上(含95%)复发肿瘤体积位于首次治疗95%的等剂量曲线内为野内复发;20%～95%的复发体积位于首次治疗95%等剂量曲线内为边缘复发;小于20%的复发体积位于该曲线内为野外复发。结果41例中,野内复发29例(70.7%),边缘复发9例(22.0%),野外复发3例(7.3%)。边缘和野外复发主要发生于颅底及其周围。结论鼻咽癌单纯放疗后复发主要是野内复发,但颅底区给予根治剂量有助于降低复发率。
Objective To evaluate the relationship of the locoregional recurrence after radiotherapy alone and primary radiation field in nasopharyngeal carcinoma(NPC).Methods CT images of the recurrent tumors were obtained and transferred to CT-Sim station.The volumes of recurrent tumors were mapped and the primary radiation fields were re-simulated according to medical records.Dose distributions and DVHs of the primary radiotherapy were calculated.The recurrence was classified according to the tumor volume within the 95% isodose(V95)of the primary radiation.The recurrence was classified as “in-field”,when 95% or more of recurrent tumor volume was within the 95% isodose of primary radiotherapy;as “marginal”,when 20% to 95% of recurrent tumor volume was within the 95% isodose;and as “outside”,when less than 20% of the recurrent tumor volume was inside the 95% isodose.Results Of 41 recurrent patients,there were 29(70.7%) in-field recurrences,9(22.0%) marginal recurrences and 3(7.3%) outside recurrences.Marginal and outside recurrence were mostly within the skull base and surrounding area.Conclusion Most of the recurrence of NPC were in-field.Adequate coverage of the skull base may reduce local recurrence.
出处
《实用癌症杂志》
2005年第2期174-176,共3页
The Practical Journal of Cancer
基金
江西省卫生厅重大课题招标项目资助
课题编号:20010213
