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Updated: Jan 10, 2026
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Feasibility of treatment planning with HyperArc stereotactic radiosurgery methods for ocular tumors
Chase Cochran1, Shane McCarthy1, William St Clair1
1Medical Physics Graduate Program, Department of Radiation Medicine, University of Kentucky, Lexington, Kentucky, USA.
Purpose/Objectives:
Currently, ocular disease is primarily managed with COMS plaque brachytherapy. Various stereotactic radiosurgery (SRS) platforms have also been employed, yet widespread access remains a challenge. Herein, we demonstrate the feasibility of using the HyperArc SRS system to provide an additional platform for the treatment of ocular malignancies.
Materials/Methods:
Twenty previously treated COMS patients with ocular melanoma were selected for a retrospective HyperArc SRS planning study. The average gross tumor volume (GTV) derived from MRI was 1.19 ± 0.60 cc. Planning target volumes (PTV) were generated from a 2 mm expansion of the GTVs. HyperArc plans were created for a TrueBeam LINAC (6MV-FFF) with the Encompass support system and used the AcurosXB algorithm for dose calculation. A dose of 25 Gy was prescribed to the PTVs and all plans were normalized such that PTVD95% = 25 Gy. All organs at risk (OARs) were spared adequately. Patient-specific quality assurance (QA) and an independent Monte Carlo (MC) second check was performed for all SRS plans.
Results:
HyperArc plans demonstrated high conformality Paddick conformity index (PCI = 0.84 ± 0.04) with steep dose gradient index (GI = 3.29 ± 0.38). Compared to the HyTEC standard (12.1 Gy), it adequately spared the optic nerve(s) (Dmax = 7.18 ± 1.26 Gy, p < 0.001). Adequate PTV coverage (D99% = 23.80 ± 0.46 Gy) was achieved with a mean GTV dose of 27.54 ± 0.47 Gy. Maximum dose to critical OARs were controlled: brain (6.00 ± 1.50 Gy), optic nerve (7.18 ± 1.26 Gy), and ipsilateral lens (9.36 ± 5.67 Gy). Average beam-on time was under 9 min. End-to-end QA results showed a 99.00 ± 0.59% pass rate (2%/2 mm γ-criteria), with a MC check showing 97.81 ± 1.24% agreement with the AcurosXB algorithm (2%/2 mm).
Conclusion:
HyperArc SRS plans provided adequate target coverage, acceptable OARs sparing, and offer a fast, safe, and non-invasive treatment option for ocular tumors. Clinical implementation of this novel methodology is ongoing at our institution.
