头颈部癌影像引导调强放射治疗的探讨

KV-X CBCT on geometricl accuracy of IMRT of head and neck cancers

目的:探讨影像引导放射治疗技术应用于头颈部癌调强放射治疗的意义。方法:2006-11-2007-10采用影像引导调强放疗技术全程根治性治疗头颈部肿瘤患者53例,均采用IM-RT技术进行。影像引导采用CBCT模式,前3次治疗前均先行CBCT扫描,以后每周1次,共行CBCT扫描352次。结果:53例患者首次治疗前CBCT扫描共53次,在纵向、垂直和横向方向上的误差分别为(0.139±0.138)、(0.213±0.166)和(0.164±0.396)cm,在旋转方向上的误差为(0.151±0.601)度。除首次扫描外,其余299次CBCT扫描在纵向、垂直和横向方向上的误差分别为(0.145±0.166)、(0.151±0.130)和(0.149±0.150)cm,在旋转方向上的误差为(0.146±0.366)度。结论:首次治疗前CBCT确定了精确治疗摆位的基准,此后的CBCT扫描对于确保治疗摆位的精确重复具有重要作用。

OBJECTIVE： To evaluate the role of KV-X CBCT on the geometricl accuracy of IMRT of head and neck cancers. METHODS： From Nov. 2006 to Oct. 2007, 53 patients with head and neck cancers were treated with IMRT for curative intent. The CBCT scans were used for detecting the geometric errors of setup. The CBCT scans were carried out once a time in the first 3 fractonns of the treatment and in the followings once a week. There were 352 scans. RESULTS： The first time mean setup errors of the treatment were （0. 139±0. 138）, （0. 213±0. 166）, （0. 164±0. 396） cm and （0. 151± 0. 601） degrees in lateral, ventral-dorsal, cranialcaudal and rotational directions respectively. The setup errors of the following treatment were （0.145±0.166）, （0.151±0.130）, （0.149±0.150） cm and （0.146±0.366） degrees respectively. CONCLUSIONS： The IMRT delivery of this group was highly accurate. The CBCT plays a key role in the guarantee of accurate delivery of IMRT for head and neck cancers.