Progress of standard loading pattern of high-dose-rate brachytherapy in cervical cancer

Brachytherapy plays an important role in radical radiotherapy of cervical cancer. At present, most hospitals in China use high-dose-ate brachytherapy, which irradiatevolume by simulating line source with a single approximate point source. Therefore, the dwell positions and dwell times can be optimized appropriately. However, due to various reasons, the initial state of the optimization plan must start from the standard loading pattern, and ensure that the optimized plan basically maintains the pear-shaped dose distribution. This paper introduces the standard loading pattern of intracavitary brachytherapy and intracavitary combined interstitial brachytherapy for cervical cancer through literature review, and expounds the planning optimization model and the constraints in the optimization process, to provide important reference for the planning of brachytherapy for cervical cancer. 摘要： 近距离放射治疗在宫颈癌的根治性放射治疗中有着重要的地位。目前, 国内绝大部分医院采用高剂量率近距 离治疗方式, 通过单一近似点源模拟线源来实现体积照射。因此, 驻留位置和驻留时间可以进行适当的优化。然而, 由 于种种原因优化计划的初始状态必须从标准载源模型开始, 并且保证优化后的计划基本保持梨形剂量分布。本文通 过文献综述介绍了宫颈癌腔内近距离治疗以及腔内联合组织间插植近距离治疗的标准载源模型, 并对计划优化模型 和优化过程中的限制条件等做适当阐述, 以期为宫颈癌近距离治疗计划设计提供重要参考。