Forward treatment planning techniques to reduce the normalization effect in Gamma Knife radiosurgery
Hao-Wen Cheng1,2, Wei-Lun Lo3,2,4, Chun-Yuan Kuo1,5
1Department of Radiation Oncology, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan.
Journal of Applied Clinical Medical Physics
|September 30, 2017
Summary
Gamma Knife treatment planning can be improved by reducing the normalization effect. New techniques optimize dose distribution, enhancing target coverage and potentially lowering complication risks.
Area of Science:
- Neurosurgery
- Radiation Oncology
- Medical Physics
Background:
- Normalization effect in Gamma Knife (GK) forward treatment planning can compromise coverage of high-value isodose lines for large lesions.
- Optimizing dose distribution is crucial for effective radiation therapy.
Observation:
- Multiple shots in GK planning can lead to the normalization effect, reducing target coverage.
- The Leksell Gamma Knife Perfexion system offers new possibilities for normalization effect mitigation using composite shots.
Findings:
- Adjusting shot positions and weightings effectively reduces the normalization effect by minimizing high-isodose line overlap.
- Proposed forward planning techniques successfully mitigate the normalization effect, improving target coverage and dose uniformity.
Implications:
- Reduced normalization effect leads to increased coverage of higher isodose lines within targets.
- Mitigating this effect allows for higher prescribed marginal doses, more uniform target irradiation, and reduced risk of complications.
