鼻咽癌放疗采用非共面多野适形照射所致剂量学优劣对比

目的:对于鼻咽癌放疗病人进行三维适形、非共面多野适形和调强放射治疗三种方式比较,分析其各自优缺点,指导临床应用。方法:收集病人资料,经CT定位后通过计划系统设计。三维适形计划设计给于病人面颈联合野对穿照射后缩小范围避开脊髓对穿照射同时加照电子线野,达到预防量后再次缩小照射范围并对原发灶区域放疗至根治量;非共面多野适形计划设计在三维适形面颈联合野基础上加照鼻前野和颅顶野,避免使用X线与电子线衔接照射,达到预防量后缩小范围对原发灶加量;调强计划设计使用逆向治疗计划设计,给于目标组织一定的剂量与体积后计算,通过调整使各靶区或正常组织精确受量,提供优于传统放疗的靶区剂量覆盖和正常组织保护。结果:分析计划数据可见,三维适形计划中靶区剂量均匀性欠佳,对于腮腺无法起到保护作用;非共面多野适形计划靶区均匀性优于前者且对于腮腺有较好保护,但对于脑组织和视觉系统存在一定损伤,由于入射路径较长引发随机性放射损伤概率增加;调强放射治疗计划在靶区内剂量均匀性和正常组织受量可控性方面均优于前二者。结论:三维适形放射治疗使用广泛而操作简便,但不存在剂量学优势,非共面多野适形照射技术存在一定缺陷,但剂量学优于三维适形计划,调强放疗计划对于剂量的全面精确性控制,证明其应用于鼻咽癌放疗的绝对优势地位。

Radiotherapy for Nasopharyngeal Carcinoma with Non-coplanar Hatano Conformal Radiation Dosimetry Advantages and Disadvantages of Contrast Due to

For nasopharyngeal cancer patients undergoing radiotherapy and three-dimensional conformal the noncoplanar Hatano conformal and intensity modulated radiation therapy in three ways to analyze their respective advantages and disadvantages, to guide the clinical application. Methods： patient data, through the planning system design after CT location. Three-dimensional conformal plan designed for patients face, neck and joint wild Narrow wear after irradiation to avoid the spinal cord wear irradiation at the same time add photos line the wild, illuminated area and regional radiotherapy of the primary tumor to cure is prevention of the amount of shrink again; non-total face more than wild fitness-shaped plan design on the three-dimensional e~nformal：shaped surface of the neck joint wild basis plus according to the nose before the wild and cranial top wild, avoid the use of X-ray and electronic wire convergence irradiation, to the prevention of the amount of narrowing the scope of the primary tumor, plus the amount; intensity modulated plan designed to reverse treatment planning, to the target tissue dose and volume calculation precision by volume, superior to conventional radiotherapy target volume dose coverage and normal tissue ＇protection by adjusting the target or normal tissue. Results： analysis of plan data, the poor uniformity of the target dose in the three-dimensional conformal plans for the parotid gland is unable to play a protective role; non-coplanar Hatano conformal plan target uniformity better than the former and better protection for the parotid some damage, but for the brain tissue and the visual system due to the incident path longer caused by the randomness of radiation injury and the probability of increase; IMRT dose uniformity and normal tissue of the target area by the amount of controllability are better I than the first two persons. Conclusions： The three-dimensional conformal radiation therapy is, widely used and easy to operate, but there is no dosimetric advantage of non-coplanar wild fitness-shaped irradiation technology has some defects, but the dosimetry is better than the three-dimensional conformal plan, intensity,modulated radiotherapy plans for dose-round the accuracy of control, to prove their absolute dominance used in radiotherapy for nasopharyngeal carcinoma.