E-ISSN: 1019-5157
ISSN: 2651-5024
Research
Comparative Analysis of Stereotactic Radiosurgery Modalities in Brain Metastases
Esil Kara✉ ,
Gulcihan Colak ,
Fatih Ozcan ,
Guler Yavas
Radiation Oncology, Lösante Child and Adult Hospital
DOI: 10.5137/1019-5149.JTN.50568-26.3
Article in Press
Corresponding Author:
Esil Kara (esilkara@hotmail.com)
Abstract
Aim
This study aims to compare the dosimetric performance and QA outcomes of CyberKnife, Radixact, and Linac-based VMAT (Monaco and RayStation TPS) for brain metastases, providing evidence-based guidance for modality selection based on tumor characteristics and clinical priorities.
Material and Methods
This retrospective study included ten lung cancer patients with brain metastases previously treated with linac based SRS using the Monaco TPS, replanned with each modality. By using Paddicks Conformity Index (CI), Gradient Index (GI), and normal brain volume receiving ≥12 Gy (V12) parameters dosimetric quality was evaluated. Platform-specific QA procedures were performed in accordance with routine clinical practice. One-Way ANOVA and Tukeys post-hoc tests were used to test statistical significance (p < 0.05).
Results
All platforms achieved clinically proper target coverage and organ-at-risk sparing. CyberKnife demonstrated lower GI (4.86 ± 1.57) and V12 (3.29 ± 2.98 cc), indicating steeper dose gradients and reduced normal brain dose, especially for small PTVs compared with linac-based and Radixact plans, consistent with non-isocentric delivery characteristics. QA results for all systems met institutional tolerance criteria; however direct comparison of QA performance was limited by the use of different, modality-specific verification methodologies.
Monaco and RayStation yielded lower CI (0.73 ± 0.07; 0.70 ± 0.05) and required fewer MUs (3769.65 ± 825.10; 3516.13 ± 420.83). For PTVs >4 cc, V12 exceeded 10 cc in all modalities except CyberKnife. CI differences were evaluated as statistically significant (p < 0.001), GI (p < 0.05), and QA (p < 0.001).
Conclusion
This study demonstrates modality-specific dosimetric differences among commonly used SRS platforms that may be relevant for normal brain dose sparing. Future investigations incorporating larger patient cohorts and long-term clinical endpoints may further clarify how these dosimetric differences variations into clinical outcomes.
This study aims to compare the dosimetric performance and QA outcomes of CyberKnife, Radixact, and Linac-based VMAT (Monaco and RayStation TPS) for brain metastases, providing evidence-based guidance for modality selection based on tumor characteristics and clinical priorities.
Material and Methods
This retrospective study included ten lung cancer patients with brain metastases previously treated with linac based SRS using the Monaco TPS, replanned with each modality. By using Paddicks Conformity Index (CI), Gradient Index (GI), and normal brain volume receiving ≥12 Gy (V12) parameters dosimetric quality was evaluated. Platform-specific QA procedures were performed in accordance with routine clinical practice. One-Way ANOVA and Tukeys post-hoc tests were used to test statistical significance (p < 0.05).
Results
All platforms achieved clinically proper target coverage and organ-at-risk sparing. CyberKnife demonstrated lower GI (4.86 ± 1.57) and V12 (3.29 ± 2.98 cc), indicating steeper dose gradients and reduced normal brain dose, especially for small PTVs compared with linac-based and Radixact plans, consistent with non-isocentric delivery characteristics. QA results for all systems met institutional tolerance criteria; however direct comparison of QA performance was limited by the use of different, modality-specific verification methodologies.
Monaco and RayStation yielded lower CI (0.73 ± 0.07; 0.70 ± 0.05) and required fewer MUs (3769.65 ± 825.10; 3516.13 ± 420.83). For PTVs >4 cc, V12 exceeded 10 cc in all modalities except CyberKnife. CI differences were evaluated as statistically significant (p < 0.001), GI (p < 0.05), and QA (p < 0.001).
Conclusion
This study demonstrates modality-specific dosimetric differences among commonly used SRS platforms that may be relevant for normal brain dose sparing. Future investigations incorporating larger patient cohorts and long-term clinical endpoints may further clarify how these dosimetric differences variations into clinical outcomes.
Keywords
Radiosurgery
brain metastases
cyberknife
radixact