鼻咽癌患者放化疗过程中肿瘤和腮腺的形态变化

Anatomic Changes of Tumor and Parotid during the Chemoradiation for Nasopharyngeal Carcinoma

目的研究局部晚期鼻咽癌患者在新辅助化疗联合同步放化疗过程中肿瘤及腮腺解剖形态变化规律。方法选择2014年5—9月收治的15例初诊鼻咽癌患者。患者均接受新辅助化疗联合同步放化疗,放疗采用调强放疗。新辅助化疗前(P1点)、后(P2点)、放疗剂量至40 Gy(P3点)及放疗结束同日(P4点)分别行4次定位CT扫描,分别勾画出肿瘤靶区及危及器官。获取各组CT图像中肿瘤和腮腺的体积,对比不同组之间的变化。结果相对于P1点体积,鼻咽原发灶和颈部转移淋巴结体积在P2,P3,P4点分别缩小至(55.74±9.27)%及(48.96±26.17)%,(37.24±12.37)%及(21.01±13.09)%,(27.22±6.88)%及(13.33±10.89)%。腮腺相对于P1点,在P2点没有明显变化,P3,P4点分别缩小至(67.61±9.70)%,(67.10±10.58)%。结论对鼻咽原发灶及颈部转移淋巴结通过放疗前勾画区域进行计划设计对于肿瘤患者有较大收益。放疗中腮腺体积也明显缩小,在放疗累计剂量达40 Gy时调整放疗计划能够使腮腺获益较大。

Objective To investigate the anatomic changes of tumor and parotid during radiotherapy with chemotherapy for nasopharyngeal carcinoma（NPC）. Methods From May 2014 to September 2014, 15 patients with NPC treated with neo-adjuvant chemotherapy followed by radiotherapy with concurrent chemotherapy（CCRT） were included. CT scans were performed before treatment（P1）, after 2 cycles of neo-adjuvant chemotherapy（P2）, in the period of IMRT（the radiation dose of 40 Gy）（P3） and at the treatment end（P4）. All target volumes and normal structures were manually outlined on the CT images. The volumes of tumor and parotid were gotten from all CT scans and compared the changes between P1, P2, P3, and P4 point. Results Compared with P1 point, the volumes of primary gross target volume（GTVnx） and the involved lymph nodes（GTVnd） reduced to（55.74±9.27）% and（48.96 ±26.17） %（P2）,（37.24±12.37） % and（21.01±13.09）%（P2）,（27.22±6.88）% and（13.33± 10.89）%（P3）, respectively. Compared with P1 point, the volume of parotids didn＇t change at P2 point, but reduced to（67.61±9.70）%（P3） and（67.10±10.58）%（P4）, respectively. Conclusion Significant volumetric changes of target volumes were observed during the treatment. Making plan when the neo-adjuvant chemotherapy was finished can benefit GTVnx and GTVnd. There is also significant changes of parotids volume. Parotid can benefit from replanning at 40 Gy of treatment dose.