鼻咽癌旋转调强与固定野动态调强的剂量学比较研究

发布时间：2018-04-20 06:35

本文选题：快速旋转调强 + 动态调强　；参考：《南华大学》2011年硕士论文

【摘要】：固定野调强适形放疗(Intensity-modulated radiotherapy,IMRT)已广泛应用于鼻咽癌的治疗,但IMRT也存在总跳数过高,实际治疗时间较长等不足。近年,旋转调强放疗(Intensity-modulated arc radiotherapy,IMAT)开始应用于临床,国外已有不少体部肿瘤的相关报道,但头颈部特别是鼻咽肿瘤的报道较少。IMAT治疗鼻咽癌在剂量学方面是否优于调强放疗还有待进一步研究。国内个别中心已有初步结果,但尚缺乏多中心病例研究的支持,特别是各中心鼻咽癌的处方剂量存在差异,治疗计划设计也存在很大的人为因素,同时治疗实施的配套硬件也各有不同。因此有必要继续进行相关的研究,为进一步开展旋转调强技术提供临床支持。本文通过收集湘雅肿瘤中心2010年10月至2011年2月期间经病理活检确诊的12例实施根治性放疗的鼻咽癌患者,经模拟CT扫描后传输图像至Varian Eclipse 8.6 TPS,勾画靶区及危及器官,对12例鼻咽癌患者分别采用瓦里安旋转调强(IMAT)技术RapidARC和固定野动态调强(dIMRT)方式设计同步推量放疗计划。在满足95%计划靶体积达处方剂量的情况下,比较两种计划的平均剂量体积直方图、靶区和危及器官剂量、正常组织、机器跳数和治疗时间。研究结果表明RapidARC靶区受到的处方剂量与dIMRT相似,总体上靶区平均剂量、最大剂量和受照107%以上处方剂量的体积(V107)稍高于dIMRT;脊髓、视神经、晶体、颞颌关节等危及器官剂量学指标无统计学差异。脑干最大剂量RapidARC稍高于dIMRT。左、右腮腺平均剂量和50%腮腺受照的剂量(D50) RapidARC比dIMRT高。正常组织定义为体表轮廓区域(BODY)减去PTV,即[B-P]受照小于800cGy的体积RapidARC比dIMRT高,受照1200～4500cGy的体积RapidARC比dIMRT低。RapidARC比dIMRT的单次总机器跳数平均减少了61.9%,单次治疗时间平均减少了62.3%。总之,两种计划剂量学存在一定差异,但都能满足临床要求,旋转调强减少了正常组织受量,显著降低了机器跳数,大大缩短了治疗时间。
[Abstract]:Intensity-modulated radiation therapy (IMRT) has been widely used in the treatment of nasopharyngeal carcinoma (NPC), but IMRT also has some shortcomings, such as high total jump number and long actual treatment time. In recent years, Intensity-modulated arc radiation therapy (IMATT) has been used in clinical practice. However, there are few reports of head and neck tumors, especially nasopharynx tumors. Whether IMAT is better than intensity modulated radiotherapy in the treatment of nasopharyngeal carcinoma needs further study. Preliminary results have been obtained from individual centers in China, but there is a lack of support for multi-center case studies. In particular, there are differences in the prescription dose of nasopharyngeal carcinoma in different centers, and there are also a lot of human factors in the design of treatment plans. At the same time, treatment implementation of the supporting hardware is also different. Therefore, it is necessary to continue the related research to provide clinical support for the further development of rotational intensity modulation technology. From October 2010 to February 2011, 12 patients with nasopharyngeal carcinoma (NPC) who underwent radical radiotherapy were collected from Xiangya Cancer Center from October 2010 to February 2011. The images were transmitted to Varian Eclipse 8.6TPS after simulated CT scanning, and the target areas and dangerous organs were delineated. Twelve patients with nasopharyngeal carcinoma were treated with Varian rotation intensity modulation (RapidARC) and fixed field dynamic intensity modulation (IMRT). In the case of 95% target volume reaching the prescribed dose, the average dose volume histogram, target area and organ dose, normal tissue, machine hopping and treatment time of the two plans were compared. The results show that the prescription dose of RapidARC target area is similar to that of dIMRT, and the average dose, maximum dose and the volume of the prescription dose above 107% of the total target area are slightly higher than those of dIMRT, spinal cord, optic nerve, lens, etc. There was no statistical difference in dose indices of temporomandibular joint and other dangerous organs. The maximum dose of RapidARC in brain stem was slightly higher than that in dIMRT. The average dose of left and right parotid gland and the dose of 50% irradiation on parotid gland were higher than that of dIMRT. Normal tissue was defined as body surface contour area (BODY) minus PTVs, that is, the volume of [B-P] exposed to 800cGy was higher than that of dIMRT, and the volume of RapidARC of exposed 1200~4500cGy was lower than that of dIMRT. RapidARC reduced the average number of single total machine jumps by 61.9%, and the average time of single treatment was 62.3% lower than that of dIMRT. In a word, there are some differences between the two kinds of planned dosimetry, but both of them can meet the clinical requirements. Rotation intensity modulation can reduce the normal tissue intake, reduce the number of machine hops significantly, and shorten the treatment time greatly.
【学位授予单位】：南华大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：R739.63

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