Principles and Applications of Stereotactic Radiosurgery and Stereotactic Body Radiation Therapy

Stereotactic radiation therapy (RT) involves the delivery of high dose-per-fraction treatments to small intracranial (stereotactic radiosurgery [SRS]) and extracranial (stereotactic body radiotherapy [SBRT]) sites. SRS and SBRT share several overarching principles that differentiate stereotactic RT from conventionally fractionated radiation techniques. This review describes historical aspects of SRS/SBRT and definitions thereof, and a comparison with more modern semantics. Key principles of the stereotactic radiotherapeutic modalities are discussed, followed by an overview of the technical considerations involved. Lastly, the accepted appropriate clinical indications for stereotactic RT are outlined, and the potential role of stereotactic treatment in future oncologic management are also discussed.