Two-dimensional dose distribution of a miniature x-ray device for stereotactic radiosurgery.
The Photon Radiosurgery System is a miniature x-ray device developed for the treatment of small intracranial neoplasms. The x-rays are generated at the tip of a 10-cm-long, 3-mm-diam probe with a nearly isotropic distribution. Results from measurements of the two-dimensional dose distribution around the x-ray source are presented using two methods: (1) dose measurement with an ionization chamber and a water phantom system and (2) dose measurement with radiochromic film and a solid water phantom. The shape of the two angular dose distributions in the axial plane agree with each other to with approximately 10% and the dose at 10 mm from the source, orthogonal to the probe axis, was about 20% lower than at the same distance along the axis. The relative dose difference of 20% corresponds to a change in distance from the source of +/- 0.3 mm at 10 mm. It is shown that the anisotropy of radiation distribution in the axial plane can be improved to approximately 10% by adjusting the electron beam with a 12% reduction in the overall radiation output.
Department of Physics, Northeastern University, Boston, Massachusetts 02115, USA.
T
T
Yasuda
J
J
Beatty
P J
PJ
Biggs
K
K
Gall
D002138:Calibration; D004307:Dose-Response Relationship, Radiation; D008904:Miniaturization / Q000295:instrumentation*; D019047:Phantoms, Imaging; D011874:Radiometry / Q000295:instrumentation; D016634:Radiosurgery / Q000295:instrumentation*; D014867:Water; D014962:X-Ray Film; D014964:X-Ray Therapy / Q000295:instrumentation*
D014867:Water