Dosimetric Evaluations of HyperArc and RapidArc in Stereotactic Radiosurgery for a Single Brain Metastasis
10.14316/pmp.2024.35.2.36
- Author:
So-Yeon PARK
1
;
Noorie CHOI
;
Na Young JANG
Author Information
1. Department of Radiation Oncology, Veterans Health Service Medical Center, Seoul, Korea
- Publication Type:Original Article
- From:
Progress in Medical Physics
2024;35(2):36-44
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:This study assessed and compared the dosimetric performance of HyperArc and RapidArc in stereotactic radiosurgery (SRS) for a single brain metastasis.
Methods:Twenty patients with intracranial brain metastases, each presenting a distinct target volume, were retrospectively selected. Subsequently, volumetric modulated arc therapy (VMAT) plans were designed using RapidArc (VMATRA ) and HyperArc (VMATHA ) for each patient. For planning comparisons, dose-volumetric histogram (DVH) parameters for planning target volumes (PTVs) and normal brain regions were computed across all VMAT plans. Subsequently, their total monitor units (MUs), total beam-on times, and modulation complexity scores for the VMAT (MCSv ) were compared. A statistical test was used to evaluate the dosimetric disparities in the DVHparameters, total MUs, total beam-on times, and MCSv between the MATHA and VMAT sub>RA plans.
Results:For the PTVs, VMATHA presented a higher homogeneity index (HI) than VMAT RA . Moreover, VMATHA presented significantly smaller gradient index (GI) values (P<0.001) than VMATRA . Thus, VMATHA demonstrated better performance in the DVH parameters for the PTV than VMATRA . For normal brain tissues, VMATHA presented lower volume receiving 50% of the prescription dose and V 2Gy to the normal brain tissues than VMATRA (P<0.0001). While the total MUs required for VMATHA was significantly higher than those for VMATRA , the total beam-on time for VMATHA was superior to that for VMATRA .
Conclusions:Thus, VMATHA exhibited superior performance in achieving rapid dose fall-offs (as indicated by the GI) and a higher HI at the PTV compared to VMATRA in brain SRS. This advancement positions HyperArc as a significant development in the field of radiation therapy, offering optimized treatment outcomes for brain SRS.
