ABSTRACT
In the past two decades, developments in radiosurgery tech - nology have progressed at a torrid pace, with innovations in - cluding MR localization, image fusion, dedicated radiosurgery
linacs, relocatable frames, micro-multileaf collimators, imageguided (“frameless”) localization techniques, and application to extracranial tumor sites. Guidance for radiosurgery quality assurance has signicantly lagged the technological development. e primary reference document today, AAPM Report No. 54 “Stereotactic Radiosurgery” (Schell et al. 1995), was published nearly 15 years ago and covers none of the more recent innovations noted above. Several relevant eorts originating within the American Association of Physicists in Medicine are presently ongoing and are expected to be completed and published in the near future. ese include:
Task Group 101-“Stereotactic Body Radiotherapy”• Task Group 104-“KiloVoltage Localization in erapy”• Task Group 117-“Use of MRI Data in Treatment • Planning and Stereotactic Procedures-Spatial Accuracy and Quality Control Procedures” Task Group 132-“Use of Image Registration and Data • Fusion Algorithms and Techniques in Radiotherapy Treatment Planning” Task Group 135-“QA for Robotic Radiosurgery”• Task Group 155-“Small Fields and Non-Equilibrium • Condition Photon Beam Dosimetry” Task group 178-“Gamma Stereotactic Radiosurgery • Dosimetry and Quality Assurance”
In the absence of a modern, comprehensive radiosurgery QA document, this chapter is intended to provide guidance and examples for assessing and minimizing geometric (localization) and dosimetric uncertainties in cranial stereotactic radiosurgery and stereotactic radiation therapy. Other chapters in this edition are dedicated to gamma-and robotic-based radiosurgery; thus, this chapter focuses primarily on linear accelerator (linac)-based stereotactic radiosurgery/stereotactic radiation
Introduction .........................................................................................................................................361 Geometric Localization ..................................................................................................................... 362 Isocentric Accuracy in Stereotactic Radiosurgery • End-to-End Target Localization Dosimetric Localization .................................................................................................................... 365 Beam Data Acquisition • End-to-End Dosimetric Commissioning Summary ..............................................................................................................................................370 References .............................................................................................................................................370
