Stitt J A, Thomadsen B R
University of Wisconsin Comprehensive Cancer Center, Madison 53792, USA.
Semin Oncol. 1997 Dec;24(6):696-706.
The treatment of cancer with radioactive sources using topical molds and intracavitary radium showed the efficacy of brachytherapy long before external radiation therapy became common practice. Brachytherapy is progressing in several clinical directions that reflect technological innovation as well as changes in medical care which combine to provide significant advances in the practice of brachytherapy today. A major change in brachytherapy, the development of high intensity sources, promoted clinical and technologic innovations in high dose-rate brachytherapy. Pulse dose-rate brachytherapy is the use of these sources to treat a target by using pulses of radiation for several minutes each hour with the same overall time and total dose as low dose-rate treatment. Recent novel approaches of using radiotherapy for prevention of restenosis in coronary and peripheral vessels has interested laboratory and clinical researchers. Most of the work toward new source material for brachytherapy centers around intravascular applications. Technology to support brachytherapy continues to advance rapidly. The interaction between images from diverse modalities and the various phases of the treatment planning is the basis of enhanced treatment planning procedures. Optimization in brachytherapy entails calculating the source strengths or source dwell times to satisfy a set of dose criteria to achieve the best dose distribution for a brachytherapy implant. Progress in computerization and calculation modeling has promoted this technical advance. Education and training in brachytherapy indications and techniques is mandatory to maintain high standards of brachytherapy practice.
在外部放射治疗成为常规治疗方法之前很久，使用局部模具和腔内镭源进行放射源癌症治疗就已显示出近距离放射治疗的疗效。近距离放射治疗正在多个临床方向取得进展，这些进展反映了技术创新以及医疗护理的变化，二者共同为当今近距离放射治疗实践带来了重大进步。近距离放射治疗的一项重大变革——高强度源的发展，推动了高剂量率近距离放射治疗的临床和技术创新。脉冲剂量率近距离放射治疗是指利用这些源，通过每小时进行几分钟的辐射脉冲来治疗靶区，其总时间和总剂量与低剂量率治疗相同。近期，使用放射疗法预防冠状动脉和外周血管再狭窄的新方法引起了实验室和临床研究人员的兴趣。近距离放射治疗新源材料的大部分工作都围绕血管内应用展开。支持近距离放射治疗的技术持续快速发展。来自不同模态的图像与治疗计划的各个阶段之间的相互作用是强化治疗计划程序的基础。近距离放射治疗中的优化需要计算源强或源驻留时间，以满足一组剂量标准，从而为近距离放射治疗植入实现最佳剂量分布。计算机化和计算建模方面的进展推动了这一技术进步。必须进行近距离放射治疗适应症和技术方面的教育与培训，以维持近距离放射治疗实践的高标准。
