Research Information System
Clinical and Experimental Metastasis, vol.42, no.6, 2025 (SCI-Expanded)
This study aims to compare the dosimetric performance of GammaKnife ICON and CyberKnife S7 radiosurgery systems in the treatment of single brain metastases using a fractionated stereotactic schedule. Fifteen patients with single brain metastases were retrospectively and consecutively included. For each patient, treatment plans were generated using both GammaKnife ICON and CyberKnife S7 systems, delivering a total dose of 27 Gy in three fractions. Dosimetric parameters including Paddick Conformity Index (PCI), Gradient Index (GI), Heterogeneity Index (HI), beam-on time (BOT), and doses to organs at risk (OARs) were compared across modalities and stratified by target volume. GammaKnife plans showed significantly higher PCI (0.862 vs. 0.825; p < 0.05) and lower HI (1.94 vs. 2.09; p < 0.05), indicating superior dose conformity and acceptable heterogeneity. GI was lower for GammaKnife, though not statistically significant. BOT was significantly shorter for GammaKnife (14.2 vs. 34.3 min; p < 0.05). Brainstem doses were significantly lower in GammaKnife plans, especially for lesions close to critical structures. Volume-based subgroup analysis confirmed that GammaKnife consistently delivered more conformal and steep dose distributions across all tumor sizes. GammaKnife ICON demonstrates dosimetric superiority in conformity, gradient sharpness, and treatment efficiency. These advantages may translate into improved clinical outcomes, such as enhanced local control, reduced toxicity, and increased patient comfort through shorter treatment sessions and better motion management. Gamma Knife, CyberKnife, Brain Metastasis, Radiosurgery.