Evaluation of Clinical Application and Dosimetric Comparison of Treatment Plans of Gamma Knife and CyberKnife in Treating Arteriovenous Malformations.

PURPOSE

To analyze and compare the characteristics of dose distributions for Leksell Gamma Knife Perfexion (LGK-PFX) and CyberKnife (CK) in treating arteriovenous malformations (AVMs).

SUBJECTS AND METHODS

Twenty-four patients with AVMs who received CK radiosurgery at a prescribed dose (PD) of 16-25 Gy in a single fraction were selected. A LGK-PFX treatment plan with the same PD was designed for each patient. Dosimetric values for both systems were compared with respect to the conformity index (CI); selectivity index (SI); gradient index (GI) of 75, 50, and 25% of the PD; heterogeneity index; volume of the brain tissue covered by doses of 10 and 12 Gy; maximum dose delivered to the brainstem; and beam-on time.

RESULTS

The CIs of LGK-PFX and CK were 0.744 ± 0.075 and 0.759 ± 0.071 (p = 0.385), respectively. The SIs of LGK-PFX and CK were 0.764 ± 0.081 and 0.780 ± 0.076 (p = 0.424), respectively. The GI75%, GI50%, and GI25% values of LGK-PFX and CK were 1.028 ± 0.123 and 2.439 ± 0.338 (p < 0.001), 3.169 ± 0.265 and 4.972 ± 0.852 (p < 0.001), and 8.650 ± 0.914 and 14.261 ± 2.476 (p < 0.001), respectively. Volumes of the brain tissue covered by 10 Gy and 12 Gy for LGK-PFX and CK (p < 0.001) exhibited a significant difference.

CONCLUSIONS

LGK-PFX and CK exhibited similar dose conformity. LGK-PFX showed superior normal tissue sparing.