Xin Yong, Wang Jia-Yang, Li Liang, Tang Tian-You, Liu Gui-Hong, Wang Jian-She, Xu Yu-Mei, Chen Yong, Zhang Long-Zhen
Department of Radiatiotherapy, Xuzhou Medical College Affiliated Hospital, Xuzhou, China.
Asian Pac J Cancer Prev. 2012;13(3):985-9. doi: 10.7314/apjcp.2012.13.3.985.
To make sure the feasibility with (18F)FDG PET/CT to guided dynamic intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma patients, by dosimetric verification before treatment.
Chose 11 patients in III~IVA nasopharyngeal carcinoma treated with functional image-guided IMRT and absolute and relative dosimetric verification by Varian 23EX LA, ionization chamber, 2DICA of I'mRT Matrixx and IBA detachable phantom. Drawing outline and making treatment plan were by different imaging techniques (CT and (18F)FDG PET/CT). The dose distributions of the various regional were realized by SMART.
The absolute mean errors of interest area were 2.39%±0.66 using 0.6 cc ice chamber. Results using DTA method, the average relative dose measurements within our protocol (3%, 3 mm) were 87.64% at 300 MU/min in all filed.
Dosimetric verification before IMRT is obligatory and necessary. Ionization chamber and 2DICA of I'mRT Matrixx was the effective dosimetric verification tool for primary focal hyper metabolism in functional image-guided dynamic IMRT for nasopharyngeal carcinoma. Our preliminary evidence indicates that functional image-guided dynamic IMRT is feasible.
通过治疗前剂量验证，确定（18F）氟代脱氧葡萄糖正电子发射断层显像/X线计算机体层成像（PET/CT）引导下鼻咽癌动态调强放射治疗（IMRT）的可行性。
选取11例Ⅲ~ⅣA期鼻咽癌患者，采用功能影像引导IMRT治疗，并通过瓦里安23EX直线加速器、电离室、IMRT Matrixx二维电离室矩阵分析（2DICA）及IBA可拆卸体模进行绝对和相对剂量验证。分别采用不同成像技术（CT和（18F）FDG PET/CT）勾画靶区轮廓并制定治疗计划。通过剂量计算软件（SMART）实现各区域的剂量分布。
使用0.6 cc冰室电离室时，感兴趣区的绝对平均误差为2.39%±0.66%。采用剂量体积直方图分析（DTA）方法，在所有射野中，当剂量率为300 MU/min时，在我们设定的方案（3%，3 mm）内平均相对剂量测量值为87.64%。
IMRT治疗前的剂量验证是必要且必须的。电离室和IMRT Matrixx二维电离室矩阵分析是功能影像引导下鼻咽癌动态IMRT中原发灶高代谢区域有效的剂量验证工具。我们的初步证据表明功能影像引导下的动态IMRT是可行的。
