An investigation into the feasibility and efficacy of stereotactic radiosurgery for 1–3 cm single brain lesions on the ring‐mounted Halcyon LINAC
Year: 2025
Type: article
Abstract: PURPOSE: An evaluation of the accuracy, safety, and efficiency of the Halcyon ring delivery system (RDS) for stereotactic radiosurgery (SRS) treatment to relatively small (1-3 cm) brain lesions. METHODS: After completing the extensive in-house quality assurance checks including Winston-Lutz test and independent dose verification via MD Anderson IROC SRS head phantom irradiation on Halcyon, fifteen brain SRS patients previously treated with a single dose of 20 Gy on TrueBeam (6MV-FFF) with HyperArc geometry were retrospectively replanned on Halcyon (6MV-FFF). Plan quality metrics including conformity index (CI), gradient index (GI), gradient distance (GD), PTV coverage, gross tumor volume (GTV) dose, heterogeneity index (HI), and doses to organs-at-risk (OAR) including normal brain dose were evaluated. Patient-specific quality assurance (PSQA) and independent dose verification via in-house Monte Carlo (MC) 2nd checks were performed. RESULTS: (5.5 cc vs. 4.6 cc, p = 0.014), on average using Halcyon versus TrueBeam was found, albeit clinically acceptable values for the majority of brain SRS cases. Halcyon plans provided statistically insignificant maximum dose to most adjacent OARs, though there was a statistically significant decrease in the maximum dose to the spinal cord (0.1 Gy vs. 0.4 Gy, p = 0.009). Halcyon beam-on time increases by a factor of ∼2 (p < 0.001). However, the faster patient setup on Halcyon results in a comparable estimated overall treatment time for both platforms. Plan deliverability and accuracy was ensured with PSQA (> 95% pass rate for 2%/2 mm clinical gamma criteria) results and MC 2nd check agreement within ± 5.0%. CONCLUSIONS: . This study suggests that Halcyon provides acceptable treatment for solitary relatively small brain lesions of 1-3 cm in diameter. Treatment of select patients on Halcyon will be started at our clinic and it is recommended that other clinics complete an end-to-end test, validate, and implement Halcyon SRS treatments at their practices, especially community cancer centers to provide high-quality service to an underserved patient cohort.
DOI: 10.1002/acm2.70105
Authors: Kate Hazelwood, Shane McCarthy, Josh Misa, David Castelvetere, William St. Clair, Damodar Pokhrel
Institutions: Rhodes College, University of Kentucky
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $900
OpenAlex ID: W4409302455