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Abstract

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.

Document Type

Article

Publication Date

2025

Notes/Citation Information

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2025 The Author(s). Journal of Applied Clinical Medical Physics published by Wiley Periodicals, LLC on behalf of The American Association of Physicists in Medicine.

Digital Object Identifier (DOI)

https://doi.org/10.1002/acm2.70399

Funding Information

This work was partially supported by the grant from Varian Medical Systems (Palo Alto, CA).

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