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Neurooncol Adv
Neurooncol Adv
noa
Neuro-Oncology Advances
2632-2498
Oxford University Press US

10.1093/noajnl/vdae090.103
vdae090.103
Final Category: Radiation Therapy Advances
AcademicSubjects/MED00300
AcademicSubjects/MED00310
RADT-11 PREDICTING BIOPSY RESULTS OF ENLARGING BRAIN METASTASES FOLLOWING STEREOTACTIC RADIOSURGERY
Gonzalez Ariel Duke University School of Medicine, Durham, NC, USA

Haskell-Mendoza Aden Duke University School of Medicine, Durham, NC, USA

Reason Ellery Duke University School of Medicine, Durham, NC, USA

Jackson Joshua Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA

Wang Chunhao Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA

Vaios Eugene Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA

Bradbury Claire Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC, USA

Zhao Jingtong Department of Radiation Oncology, Duke University Medical Center, Durham, NC, USA

II James Herndon Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, NC, USA

Fecci Peter Preston Robert Tisch Brain Tumor Center, Durham, NC, USA
Department of Neurosurgery, Duke University Medical Center, Durham, NC, USA

8 2024
02 8 2024
02 8 2024
6 Suppl 1 2024 SNO/ASCO CNS Metastases Conference i31i32
© The Author(s) 2024. Published by Oxford University Press, the Society for Neuro-Oncology and the European Association of Neuro-Oncology.
2024
https://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com

Abstract

Stereotactic radiosurgery (SRS) is the standard of care for initial management of brain metastases (BM) and provides excellent local control with reduced incidence of adverse neurocognitive effects. However, radiographically progressive lesions post-SRS pose a key clinical challenge, as imaging characteristics cannot effectively distinguish between local recurrence (LR) and radiation necrosis (RN). A retrospective analysis was performed on patients receiving SRS treatment for BM between 2011-2022 and who subsequently underwent biopsy alone or in combination with laser interstitial thermal therapy for suspicion of LR vs RN on imaging. Patient demographics, clinicopathologic characteristics, SRS treatment parameters, and biopsy results were collected. The study included 145 patients with 151 progressive lesions biopsied after SRS treatment. The median age at biopsy was 62 (range: 27-92), with lung being the most prevalent primary site (84 cases, 57.9%). Post-SRS biopsy confirmed 92 lesions (61.3%) with RN, 58 (38.7%) with LR, and 1 biopsy result was missing. The median duration from SRS to biopsy was 13 months (range: 3-81), with a median prescribed SRS dose of 20.0 (range: 14.0-30.0) Gy. Of the lesions, 70.3% received unfractionated SRS, while 29.7% received fractionated SRS. Univariate analyses demonstrated that breast primary (vs. lung, P = 0.027, vs. skin, P = 0.012) and receipt of biopsy ≥ 9 months following SRS (P = 0.0062) were associated with lower odds of LR, while fractionation or prescribed SRS dose were not predictive. The association of biopsy timing ≥ 9 months with lower odds of LR remained significant on multivariate analyses (P = 0.0065). The natural history of LR and RN differ such that for patients presenting with an enlarging lesion ≥ 9 months post-SRS, radiation necrosis should be suspected over local tumor recurrence. Multi-disciplinary oncology teams should consider adjusting treatment for lesions progressing prior to this timepoint.
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