E-ISSN: 1019-5157
ISSN: 2651-5024
Research
Comparison of Gamma Knife and LINAC-Based Radiosurgical Techniques for Malignant Brain Tumors: Evaluation of Dosimetric Parameters and Treatment Efficacy
OZLEM DAGLI✉ ,
ESIL KARA ,
FATIH EKINCI ,
OMER HAKAN EMMEZ
DOI: 10.5137/1019-5149.JTN.49239-25.2
Article in Press
Corresponding Author:
OZLEM DAGLI (ozlemdagli@gazi.edu.tr)
Abstract
Aim
This study aims to compare Gamma Knife (GK) and Linac-based stereotactic radiosurgery (SRS) techniques for malignant brain tumors with increasing tumor volumes, focusing on Conformity Index (CI), Paddick Conformity Index (PCI), Homogeneity Index (HI), Gradient Index (GI), irradiation times, whole-brain V12 (receiving 12 Gy), and doses to organs at risk (OAR).
Material and Methods
Treatment plans were created and designed for 20 patients with malignant brain tumors using both GK and Linac-based SRS. Tumor volumes were incrementally increased by 1 mm to generate 20 plans per technique. GK plans targeted 50% isodose coverage with a 20 Gy dose, and equivalent Linac-based plans were generated for comparison. Dose-volume histograms (DVH) were analyzed to assess tissue volumes, indices (CI, PCI, HI, GI), irradiation times, and OAR doses (lens, brainstem, optic nerves, chiasm, cochlea). GI values were kept between 2.95.9, and CI was set above 0.7.
Results
GK plans showed reduced peripheral doses to healthy brain tissue compared to Linac-based SRS. For tumor volumes below 9.510 cm³, whole-brain doses were lower with GK. However, larger tumor volumes resulted in higher whole-brain doses with GK. Treatment times were shorter with Linac-based SRS. For larger volumes, fractionated radiotherapy may better mitigate potential complications.
Conclusion
The findings demonstrate that Gamma Knife offers superior performance in terms of Conformity Index (CI) and Gradient Index (GI), making it an effective choice for achieving precise dose delivery. Its sharp dose gradients and lower mean dose to the whole brain contribute to preserving healthy brain tissue.
This study aims to compare Gamma Knife (GK) and Linac-based stereotactic radiosurgery (SRS) techniques for malignant brain tumors with increasing tumor volumes, focusing on Conformity Index (CI), Paddick Conformity Index (PCI), Homogeneity Index (HI), Gradient Index (GI), irradiation times, whole-brain V12 (receiving 12 Gy), and doses to organs at risk (OAR).
Material and Methods
Treatment plans were created and designed for 20 patients with malignant brain tumors using both GK and Linac-based SRS. Tumor volumes were incrementally increased by 1 mm to generate 20 plans per technique. GK plans targeted 50% isodose coverage with a 20 Gy dose, and equivalent Linac-based plans were generated for comparison. Dose-volume histograms (DVH) were analyzed to assess tissue volumes, indices (CI, PCI, HI, GI), irradiation times, and OAR doses (lens, brainstem, optic nerves, chiasm, cochlea). GI values were kept between 2.95.9, and CI was set above 0.7.
Results
GK plans showed reduced peripheral doses to healthy brain tissue compared to Linac-based SRS. For tumor volumes below 9.510 cm³, whole-brain doses were lower with GK. However, larger tumor volumes resulted in higher whole-brain doses with GK. Treatment times were shorter with Linac-based SRS. For larger volumes, fractionated radiotherapy may better mitigate potential complications.
Conclusion
The findings demonstrate that Gamma Knife offers superior performance in terms of Conformity Index (CI) and Gradient Index (GI), making it an effective choice for achieving precise dose delivery. Its sharp dose gradients and lower mean dose to the whole brain contribute to preserving healthy brain tissue.
Keywords
Stereotactic Radiosurgery
Gamma Knife
Linac
Malignant Brain Tumors