Phillips M H, Stelzer K J, Griffin T W, Mayberg M R, Winn H R
Department of Radiation Oncology, University of Washington Medical Center, Seattle 98195.
J Clin Oncol. 1994 May;12(5):1085-99. doi: 10.1200/JCO.1994.12.5.1085.
Stereotactic radiosurgery (SRS) is an evolving modality for treating well-circumscribed intracranial lesions. Different physical methods have been developed to deliver highly localized dose distributions accurately. We review the different methods and the documented clinical results to present a coherent view of radiosurgery, and to aid physicians and physicists in the appropriate use of this modality.
A review of the medical physics and clinical literature was conducted. The physical aspects of the different methods and their impact on treatment were summarized. Results were compiled from those individual clinical series with adequate follow-up data to compare the various modalities with respect to treatment outcome for benign tumors, metastases, and vascular malformations.
The physical accuracy was comparable between radiosurgical methods. Differences between gamma radiation and linear accelerator methods had little effect on the dose distribution for single isocenter treatments. Charged particle methods could produce better dose localization for large lesions (> 25 cm3) than was possible with photon methods. Clinical results indicate similar lesion control rates between all radiosurgical methods. There was a progressive increase in the median size of treated lesions for gamma radiation, linear accelerator, and charged particle methods.
For small lesions (< 5 cm3), physical dose distributions are similar for the photon methods, but linear accelerator methods offer more flexibility for the treatment of intermediate-sized (5 to 25 cm3) lesions in applying future technical developments. More clinical results are needed before firm conclusions can be drawn on the type of lesions to be treated, and the dose-volume parameters to be used.
立体定向放射外科（SRS）是一种不断发展的治疗颅内边界清晰病变的方法。已经开发出不同的物理方法来精确地提供高度局部化的剂量分布。我们回顾不同的方法和已记录的临床结果，以呈现放射外科的连贯观点，并帮助医生和物理学家合理使用这种方法。
对医学物理和临床文献进行了综述。总结了不同方法的物理方面及其对治疗的影响。从那些有足够随访数据的单个临床系列中收集结果，以比较各种方法在治疗良性肿瘤、转移瘤和血管畸形的治疗结果方面的差异。
放射外科方法之间的物理精度相当。伽马射线和直线加速器方法之间的差异对单等中心治疗的剂量分布影响很小。对于大病变（>25 cm³），带电粒子方法比光子方法能产生更好的剂量定位。临床结果表明所有放射外科方法的病变控制率相似。伽马射线、直线加速器和带电粒子方法治疗病变的中位大小呈逐渐增加趋势。
对于小病变（<5 cm³），光子方法的物理剂量分布相似，但直线加速器方法在应用未来技术发展治疗中等大小（5至25 cm³）病变时具有更大的灵活性。在就待治疗病变的类型和要使用的剂量-体积参数得出确凿结论之前，还需要更多的临床结果。
