sreatactic 3 ch3.pdf

STEREOTACTIC IRRADIATION ❑Stereotactic irradiation comprises focal irradiation techniques that use multiple, non-coplanar photon radiation beams and deliver a prescribed dose of ionizing radiation to pre-selected and stereotactically localized lesions. ❑Equipment for stereotactic...

STEREOTACTIC IRRADIATION ❑Stereotactic irradiation comprises focal irradiation techniques that use multiple, non-coplanar photon radiation beams and deliver a prescribed dose of ionizing radiation to pre-selected and stereotactically localized lesions. ❑Equipment for stereotactic radiosurgery: ▪ Stereotactic frame: defines a fixed coordinate system for an accurate localization and irradiation of the planning target volume (PTV). ▪ Imaging equipment (CT, MRI and DSA) with which the structures, lesions and PTVs are visualized, defined and localized. ▪ Target localization software: used in conjunction with the stereotactic frame system and imaging equipment to determine the coordinates of the target in the stereotactic reference system. ▪ Treatment planning system: calculates the 3-D dose distribution and superimposes it onto the patient’s anatomical information. ▪ Appropriate radiation source and radiosurgical treatment technique. 25 M.Sc. Medical Physics Dr. Khalid I Hussein  STEREOTACTIC IRRADIATION ❑Radiosurgery is carried out mainly with ❑Gamma Knife machines, but a significant number of radiosurgical procedures is also carried out with modified isocentric linacs and Cyberknife machines. ❑CyberKnife incorporates a miniature linac mounted on a robotic arm. It is in clinical operation since the mid 1990s and in 2005 there were over 50 of these machines in clinical operation around the world. For target localization: CT and MRI 29 M.Sc. Medical Physics Dr. Khalid I Hussein