title: A tissue equivalent phantom for stereotactic radiosurgery localization and dose verification.
abstract: A tissue equivalent head phantom was utilized in the stereotactic localization and dose verification of radiosurgery procedures with the Leksell Gamma Knife Unit at the University of Kentucky Medical Center. A radiation dose-dependent color-doped gel target was positioned within the head phantom and stereotactically localized using either angiography, CT, or MR techniques. Utilizing standard Gamma Knife treatment procedures, the head phantom was irradiated, which resulted in a color change of the gel tumor at the position of the treatment isocenter and thereby confirmed the localization procedure. Additionally, a radiation dosimeter (thermoluminescent dosimetry--TLD) was positioned within the head phantom and localized using an angiography frame and a standard radiation therapy simulator. The phantom skull measurements and the dosimeter coordinates were entered into the Leksell Gamma Knife dose planning computer (KULA) and an irradiation time for 40 Gy using the 18-mm collimator was determined. The TLD dose evaluations were relatively determined using a cobalt-60 calibration curve. The experimental dose verification results agreed well (+/- 4%) with computer dose estimates.
authors.affiliation: Neurosurgery Department, University of Kentucky Medical Center, Lexington.
authors.forename: C W
authors.initials: CW
authors.lastname: Coffey
authors.forename: M
authors.initials: M
authors.lastname: Sanders
authors.forename: K
authors.initials: K
authors.lastname: Cashon
authors.forename: R
authors.initials: R
authors.lastname: Miller
authors.forename: J
authors.initials: J
authors.lastname: Walsh
authors.forename: P
authors.initials: P
authors.lastname: Patel
mesh_terms: D000465:Algorithms; D001707:Biopsy, Needle / Q000295:instrumentation; D001921:Brain / Q000473:pathology; D002533:Cerebral Angiography / Q000295:instrumentation; D006801:Humans; D008953:Models, Anatomic; D016634:Radiosurgery / Q000295:instrumentation*; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation