Advanced radiosurgery with cyberknife for recurrent pituitary adenoma

Radiosurgery is a neurosurgical treatment concept [1]. High single doses of focused radiation are used to destroy intracranial tumors. Traditionally for radiosurgery stereotactic head frames are used to enable precise target localization. The Cyberknife is a new non-invasive technology [2] for full body radiosurgery. It utilizes image guidance and robot technology for targeting and tracking of the pathologies. For intracranial application its sub-millimeter accuracy has been shown [3,4]. Since 2005 the Cyberknife has been used for radiosurgical treatment of recurrent pituitary adenomas in our center. While microsurgery is always mandatory to remove tumor mass and – if necessary – to free the optic structures from adenoma tissue, radiosurgery has been proven to be a valuable tool for residual or recurrent adenoma fragments. When compared to fractionated radiation therapy, the dose burden to the patient can be kept lower with radiosurgery. However, only small adenoma fragments with sufficient distance to the optic apparatus and clear margins are suitable for Cyberknife treatment. References: [1] Leksell L. The stereotaxic method and radiosurgery of the brain. Acta Chir Scand 1951;102:316–319; [2] Adler JR, Jr., Chang SD, Murphy MJ, et al. The Cyberknife: a frameless robotic system for radiosurgery. Stereotact Funct Neurosurg 1997;69:124–128; [3] Chang SD, Main W, Martin DP, Gibbs IC, Heilbrun MP. An Analysis of the Accuracy of the CyberKnife: A Robotic Frameless Stereotactic Radiosurgical System. Neurosurgery 2003;52:140–147; [4] Yu C, Main W, Taylor D, et al. An anthropomorphic phantom study of the accuracy of Cyberknife spinal radiosurgery. Neurosurgery 2004;55: 1138–1149