";s:4:"text";s:3286:" 4/16/2013 30 Case Studies . Safety is ensured by the medical physicist who tests the machine's mechanical functions and verifies that the imaging and treatment planning computers and software are correct and acceptable.The Gamma Knife® utilizes a technique called stereotactic radiosurgery, which uses multiple beams of radiation converging in three dimensions to focus precisely on a small volume, such as a tumor, permitting intense doses of radiation to be delivered to that volume safely. A dose reference point was chosen to be at I cm from the surface of the 8-cm-radius spherical phantom. Depending on the type of disease to be treated, various diagnostic imaging techniques can be used for localization. Although we have treated larger lesions, to maintain safety a significant increase in lesion volume must be paralleled by a decrease in delivered dose. A subset of the collimators may be removed and replaced with solid tungsten “plugs” to block individual beams in cases where additional shielding is required. Descriptive statistics were performed on this data to determine consistency and look for trends. The mechanical functions of the machine are tested on a regular basis to ensure the safety of patients and medical staff.Single-session Gamma Knife® treatment is usually unsuitable for targets larger than three or four centimeters in size.Icon treatments differ from Perfexion treatments in that:This page was reviewed on January 20, 2018Using the three-dimensional coordinates determined in the planning process, the frame is then precisely attached to the Gamma Knife® unit to guarantee that when the unit is activated, the target is placed exactly in the center of approximately 200 precision-aimed, converging beams of (Cobalt-60 generated) gamma radiation. No infections, hemorrhages, or other standard neurological complications have been reported as a result of Gamma Knife procedures. 60Co decays through beta decay to a stable isotope of nickel (60Ni) with a half life of 5.26 years. Because the radiation falloff is very steep outside the target area, the surrounding brain tissue is spared harmful after effects.
Gamma Knife radiosurgery is often a safer alternative to standard brain surgery (neurosurgery), which requires incisions in the scalp, an opening in the skull and membranes surrounding the brain, and dissection into brain tissue. In some cases, where higher than normal uncertainty may be experienced by some patients using traditional methods, CBCT localization improves upon traditional methods by defining stereotactic space at the time of patient docking into the treatment unit which is the most crucial time in the treatment workflow. A summarization of existing knowledge and results obtained in gamma knife radiosurgery worldwide is based on experience with treatment of more than 13,500 patients over 20 years at Na Homolce Hospital, Prague.