J Korean Soc Ther Radiol.
1993 Dec;11(2):431-438.
Dose Distributions for LINAC Radiosurgery with Dynamically Shaping Fields
- Affiliations
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- 1Department of Radiology, Catholic University Medical College, Seoul, Korea.
- 2Department of Neurosurgery Catholic University Medical College, Seoul, Korea.
- 3Department of Radiation Therapy Seoul National University Medical College, Korea.
Abstract
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An important problem in radiosurgery is the utilization of the proper beam parameters, to which dose shape is sensitive. Streotactic radiosurgery techniques for a linear accelerator typically, use circular radiation fields with multiple arcs to produce an spherical radiation distribution. Target volumes are irregular in shape for a certain case, and spherical distributions can irradiate normal tissues to high dose as well as the target region. The current improvement to dose distribution utilizes treating multiple isocenters or weighting various arcs to change treatment volume shape. In this paper another premising study relies upon dynamically shaping the treatment beam to fit the beam's eye view of the target. This conformal irradiation technique was evaluated by means of visual three dimensional dose distribution, dose volume histograms to the target volume and surrounding normal brain. It is shown that using even less arcs than multiple isocenter irradiation technique, the conformal therapy yields comparable dose gradients and superior homogeneity of dose within the target volume.