Commissioning and validation of a Monte Carlo algorithm for spine stereotactic radiosurgery.
Journal of applied clinical medical physics
PURPOSE: A 6FFF Monte Carlo (MC) dose calculation algorithm was commissioned for spine stereotactic radiosurgery (SRS). Model generation, validation, and ensuing model tuning are presented.
METHODS: The model was generated using in-air and in-water commissioning measurements of field sizes between 10 and 400 mm
RESULTS: Compared to open field measurements, MC calculated output factors and PDDs were within 2%, profile penumbra widths were within 1 mm, and field sizes were within 0.5 mm. Calculated point dose measurements in the StereoPHAN were within 0.26% ± 0.93% and -0.10% ± 1.37% for targets and spinal canals, respectively. Average SRSMapcheck per-plan pass rates using a 2%/2 mm/10% threshold relative gamma analysis was 99.1% ± 0.89%. Adjusting LOs improved open field and patient-specific dosimetric agreement. Anthropomorphic phantom measurements were within -1.29% ± 1.00% and 0.27% ± 1.36% of MC calculated for the vertebral body (target) and spinal canal, respectively. VIPAR gel measurements confirmed good dosimetric agreement near the target-spine junction.
CONCLUSION: Validation of a MC algorithm for simple fields and complex SRS spine deliveries in homogeneous and heterogeneous phantoms has been performed. The MC algorithm has been released for clinical use.
Knill C, Sandhu R, Loughery B, Lin L, Halford R, Drake D, et al [Snyder M] Commissioning and validation of a Monte Carlo algorithm for spine stereotactic radiosurgery. J Appl Clin Med Phys. 2023 Jul 11:e14092. doi: 10.1002/acm2.14092. Epub ahead of print. PMID: 37431696.