非共面放疗技术的实现方式

The realization modes of non-coplanar radiotherapy technology

非共面放疗是采用多个非共面固定野或者多个非共面弧照射的放疗技术。非共面射野是各个照射野的射野中心轴不在同一平面内, 而非共面弧是指每个弧形成的轨迹不在同一个平面内。与共面放疗相比, 非共面放疗技术实现立体多角度或多弧度的照射, 提高了射线聚焦程度, 有利于拉开靶区和周围正常组织受量;其剂量学优势已在多种肿瘤上得到证实, 如颅内肿瘤、肝癌和肺癌等。非共面放疗的实现方式有多种, 按照建立的时间先后顺序分为非共面锥形放疗、非共面适形放疗、非共面调强放疗和非共面容积调强弧形治疗。本文综述这些实现方式的发展历程和原理特点。

Non-coplanar radiotherapy is a kind of radiotherapy technology which employs multiple non-coplanar fixed fields or non-coplanar arcs.The non-coplanar field can be defined that the central axis of each field is not on the same plane,while the non-coplanar arc can be described that the trajectory formed by each arc is not on the same plane.Compared with coplanar radiotherapy,non-coplanar radiotherapy can achieve multi-angle or multi-radian irradiation,which effectively improves the focusing level of ray and is beneficial to enlarge the radiation dose of the target area between the surrounding normal tissues.Its dosimetric advantages have been proven in multiple types of tumors,such as intracranial tumors,liver cancer and lung cancer,etc.Multiple approaches can be employed to realize non-coplanar radiotherapy,which can be divided into the non-coplanar conic radiotherapy,non-coplanar conformal radiotherapy,non-coplanar intensity-modulated radiotherapy and non-coplanar volumetric modulated arc therapy according to the established sequence.In this review,the development process and principal characteristics of these implementations were summarized.