Whole‐procedure clinical accuracy of Gamma Knife treatments of large lesionsa)
- 22 October 2008
- journal article
- Published by Wiley in Medical Physics
- Vol. 35 (11), 5110-5114
- https://doi.org/10.1118/1.2987669
Abstract
The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3 mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6 mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain.Keywords
This publication has 16 references indexed in Scilit:
- Effects of residual target motion for image‐tracked spine radiosurgeryMedical Physics, 2007
- Comparative study of treatment dose plans after the refinement of Leksell Gamma Knife®single-beam dose profilesMedical Physics, 2007
- A STUDY OF THE ACCURACY OF CYBERKNIFE SPINAL RADIOSURGERY USING SKELETAL STRUCTURE TRACKINGOperative Neurosurgery, 2007
- An Anthropomorphic Phantom Study of the Accuracy of CyberKnife Spinal RadiosurgeryNeurosurgery, 2004
- An Analysis of the Accuracy of the CyberKnife: A Robotic Frameless Stereotactic Radiosurgical SystemNeurosurgery, 2003
- Quality assurance in stereotactic space. A system test for verifying the accuracy of aim in radiosurgeryMedical Physics, 2002
- The accuracy of dose localization for an image‐guided frameless radiosurgery systemMedical Physics, 1996
- Stereotactic RadiosurgeryNeurosurgery, 1993
- Physics of gamma knife approach on convergent beams in stereotactic radiosurgeryInternational Journal of Radiation Oncology*Biology*Physics, 1990