ESTRO 2025 - Abstract Book

S677

Clinical - CNS

ESTRO 2025

Conclusion: This case represents an innovative approach to frameless cranial stereotactic and functional radiosurgery in general anesthesia. It is opening new possibilities for adult patients with PD or tremor, as well as pediatric patients who are prone to procedural stress. Having the patient undergo the general anesthesia twice; once for simulation and once for treatment, represents a disadvantage and adds procedural complexity. However, this approach broadens treatment options for the CyberKnife system and offers major quality of life improvements.

Keywords: Stereotactic radiosurgery, thalamus

References: Tripathi M, Chauhan R, Luthra A, et al. 2023. Neurology India, 71(7):74. Goc B, Roch-Zniszczoł A, Larysz D, et al. 2023. Biomedicines, 11(2):288. Páez-Nova M, Spiegelmann R, Korn-Israeli S, et al. 2022. Neurosurgical Review, 45(3):2323–2332. Thomas E, Walker H, Middlebrooks E, et al. 2021. Int J Radiat Oncol Biol Phys, 111(3). Cho KR, Kim HR, Im YS, et al. 2015. J Korean Neurosurg Soc, 57(3):192. Singh T, Singh D, Murphy SC, et al. 2024. Cureus.

1525

Digital Poster Radiomic analysis for differential diagnosis of radiation necrosis and tumor progression following stereotactic radiosurgery in brain metastases Beatriz Vázquez-Barreiro 1 , Luis A. Pérez-Romasanta 2 , Gabriel Fernández-Calvo 3 , Iñigo Nieto-Regueira 1 , Viginia A. Ochagavía-Galilea 1 , Patricia Willisch-Santamaría 1 , Julio Vázquez-Rodríguez 4 , Guillermo Cameselle-Gagllego 1 , Aldara Candal-Meléndrez 1 , Víctor M. Muñoz-Garzón 1 1 Radiation Oncology, Hospital Meixoeiro, Vigo, Spain. 2 Radiation Oncology, Hospital Clínico Universitario Salamanca, Salamanca, Spain. 3 Department of Mathematics & MOLAB-Mathematical Oncology Laboratory, Universidad Castilla La-Mancha, Ciudad Real, Spain. 4 Radiophysics, Hospital Meixoeiro, Vigo, Spain Purpose/Objective: Stereotactic radiosurgery (SR) offers excellent control for brain metastases, but radiation necrosis (RN) can occur as a late complication. Radiomics, a computational technique, shows promise in distinguishing RN from tumor progression, improving diagnostic accuracy and treatment decisions. The goal is to assess clinical and dosimetric factors for predicting RN development, while using radiomic feature extraction to improve decision-making and patient outcomes. Material/Methods: Brain metastases treated with TrueBeam® SR from 2017-2022 were reviewed. Cases with solitary metastasis and uncertain progression versus RN on follow-up MRIs were selected, requiring at least 9 months of follow-up. Surgical excision was an exclusion criterion. Radiomic analysis was conducted on post-contrast T1 MR sequences acquired at least 4 months after the SR to minimize the effects of inflammation. The radiomic features evaluated included the distribution of voxel intensities within the image, voxel size and shape values, and the spatial distribution of gray-level intensities. Analysis was performed using 3D Slicer software (Version 5.2.1, Brigham and Women's Hospital). Univariate logistic regression will be used to assess the relationship between the confirmed diagnosis and the radiomic features. The workflow followed is shown in Figure 1.