ABSTRACT
The term 'stereotactic radiosurgery' is applied to techniques involving a well-defined co-ordinate base that enables the precise localization of a tumour and targeting of radiotherapy treatment. Stereotactic radiosurgery (SRS) uses ionizing radiation to ablate a volume of tissue, or to alter its biological activity, thus preventing further growth. The dose of radiation can be either delivered in a single treatment or in several fractions. The delivery equipment for SRS can be broadly divided into two categories: modified conventional linear accelerators; and dedicated stereotactic devices. The Gamma Knife unit uses a fixed array of 192–201 radioactive cobalt sources to deliver the dose to a patient wearing a rigid stereotactic frame to achieve precise targeting. The likelihood of trigeminal toxicity is no doubt higher for patients with tumour in contact with the nerve as a result of post-radiosurgery swelling. The majority of patients with vestibular schwannomas have unilateral sensorineural deafness at presentation.
