ABSTRACT
Linear accelerator-based radiosurgery has become more common, allowing for treatment of small intracranial and extracranial lesions with large doses of radiation using a conventional linear accelerator platform. In order to treat small fields in radiosurgery, a linear accelerator must be properly commissioned. Small field dosimetry is a challenging and often daunting task for a physicist to tackle during commissioning. This chapter discusses the challenges in small field dosimetry measurements and the dosimetric impact of incorrect setup and chamber selection. The chapter provides a practical guide on measurement setup and detector choice. It also provides a summary of output factors and detector correction factors from several manufacturers’ radiosurgery platforms including multi-leaf collimator (MLC) and cone defined fields.
