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

10.1093/noajnl/vdae090.098
vdae090.098
Final Category: Radiation Therapy Advances
AcademicSubjects/MED00300
AcademicSubjects/MED00310
RADT-02 PRE-OPERATIVE VERSUS POST-OPERATIVE FRACTIONATED STEREOTACTIC RADIOTHERAPY: A SINGLE-INSTITUTION ANALYSIS OF 534 RESECTED METASTASES
Perlow Haley Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Hennings Sarah Ohio State University School of Medicine, Columbus, OH, USA

Bradshaw Jared Ohio State University School of Medicine, Columbus, OH, USA

Reddy Sohil Ohio State University School of Medicine, Columbus, OH, USA

Luu Sydney Ohio State University School of Medicine, Columbus, OH, USA

Matsui Jennifer Ohio State University School of Medicine, Columbus, OH, USA

Klamer Brett Center for Biostatistics, The Ohio State University, Columbus, OH, USA

Dibs Khaled Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Harrell Marshall Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

McGregor John Department of Neurosurgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Lonser Russell Department of Neurosurgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Prevedello Daniel Department of Neurosurgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Elder James Department of Neurosurgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Wu Kyle Department of Neurosurgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Prabhu Roshan Levine Cancer Institute, Atrium Health, Charlotte, NC, USA

Zhu Simeng Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Singh Raj Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Beyer Sasha Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Grecula John Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Blakaj Dukagjin Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Thomas Evan Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Raval Raju Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

Palmer Joshua Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, USA

8 2024
02 8 2024
02 8 2024
6 Suppl 1 2024 SNO/ASCO CNS Metastases Conference i29i29
© 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

Patients with large or symptomatic brain metastases and limited intracranial disease typically have surgery followed by post-operative (post-op) stereotactic radiosurgery (SRS). However, SRS can lead to elevated rates of radiation necrosis (RN), meningeal disease (MD), and local failure (LF). Fractionated treatments can deliver a higher biological effective dose and may reduce the risk of LF, and pre-operative (pre-op) treatments may reduce the risk of RN and MD through treating smaller volumes and tumor sterilization. We hypothesize that pre-op fractionated stereotactic radiation therapy (FSRT) will reduce the incidence rate of RN, MD, and LF when compared to patients who receive post-op FSRT. A retrospective analysis was performed at a single institution and included patients who had surgical resection and radiation to at least one brain metastasis. Patients with multiple metastases resected, either during the same surgery or at different times in the disease course, were eligible for inclusion. Outcomes were evaluated on a per-lesion basis. The primary outcome was a composite endpoint defined by 1) LF, 2) MD, and/or 3) Grade 2 or higher (symptomatic) RN. 458 patients with 534 resected brain metastases were eligible for analysis. 235 metastases received pre-op FSRT, and 299 metastases received post-op FSRT. Overall, 15% of patients had multiple brain metastases resected. Overall, 6 (2.6%) pre-op and 13 (4.3%) post-op patients experienced LF. 21 (8.9%) pre-op and 38 (12.7%) post-op patients experienced symptomatic RN. 11 (4.7%) pre-op and 29 (9.7%) post-op patients were diagnosed with MD (p=0.031). 14% and 24% of metastases that received pre-op and post-op FSRT, respectively, experienced the composite endpoint (p=0.005). In our study, pre-op FSRT compares favorably to post-op FSRT primarily due to a 50% reduction in the incidence of MD. Differences in symptomatic RN or LF were small on adjusted analyses. Prospective validation of pre-op FSRT is needed.
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