Dosimetric Predictors of Toxicity for Brainstem Metastases and AVMs Treated With Stereotactic Radiosurgery: An International, Multi-Institutional Analysis

Authors

• Raj Singh
• Samantha Dayawansa
• Duy Pham
• Georgios Mantziaris
• Selcuk Peker
• Yavuz Samanci
• Ali Haluk Duzkalir
• David Mathieu
• Anne-Marie Langlois
• Molly L Egnot
• Ronald E Warnick
• Herwin Speckter
• Erwin Lazo
• Laura Mendez
• Angel I Blanco
• Mark J Amsbaugh
• Collin Liu
• Andrea Becerril-Gaitan
• Yoshua Esquenazi
• Ching-Jen Chen
• Peter Zaki
• Yun Liang
• Rodney Wegner
• Manjul Tripathi
• Zhishuo Wei
• Shivani A Jajoo
• Ajay Niranjan
• L Dade Lunsford
• Joshua D Palmer
• Jason P Sheehan

Language

English

Publication Date

5-1-2025

Journal

Radiotherapy & Oncology

DOI

10.1016/j.radonc.2025.110795

Abstract

Background: There are limited data on dosimetric predictors of radiation-induced changes (RICs) for brainstem metastases or arteriovenous malformations (AVMs) following single-fraction stereotactic radiosurgery (SRS).

Methods: We examined a multi-institutional cohort of patients with brainstem metastases or AVMs treated with SRS. We evaluated predictors of RICs graded per CTCAE(Common Terminology Criteria for Adverse Events), including D5%, D95%, D0.03 cc, and D0.5 cc (brainstem minus lesion). Univariate logistic regressions were initially performed with independent variables trending towards significance included on multivariate logistic regression.

Results: A total of 124 brainstem lesions treated with SRS were analyzed (21 AVMs and 103 metastases). The median prescription dose was 16 Gy(range: 13-23 Gy), and the median treatment volume was 0.48 cc(range: 0.002-11.19 cc). The incidence of RICs was 9.7 % (with 3/12 being Grade 3-4 and no Grade 5). All cases occurred in brainstem metastases, with no cases among those of the midbrain-pons transition. Treatment volumes ≥ 1cc were correlated with a higher symptomatic RIC incidence(6/57 vs. 6/65; p = 0.04). Notably, all RIC cases had a D0.5 cc ≥ 15 Gy(12/87 vs. 0/32). Both D5%≥6 Gy(9/55 vs. 3/69; p = 0.04) and D95%≥1 Gy(7/31 vs. 5/93; p = 0.01) were significantly correlated with higher incidence of RICs and D0.03 cc ≥ 22 Gy was correlated with a lower risk(2/61 vs. 9/63; p = 0.03). On MVA, D0.03 cc ≥ 22 Gy remained a significant predictor of a lower incidence of RICs(odds ratio = -1.72 (95 % CI: -3.32 to -0.12; p = 0.04).

Conclusions: Incidence of RICs was low following SRS for brainstem metastases and AVMs. We recommend optimizing radiosurgical plans for D0.5 cc < 15 Gy with consideration of D5% and D95%, with less emphasis on D0.03 cc to allow to meet the former metrics as feasible.

Keywords

Humans, Radiosurgery, Male, Female, Middle Aged, Brain Stem Neoplasms, Aged, Adult, Intracranial Arteriovenous Malformations, Radiotherapy Dosage, Aged, 80 and over, Retrospective Studies, Brain Stem, Radiation Injuries, Adverse radiation event, Arteriovenous malformation, Brainstem metastasis, Radionecrosis, Stereotactic radiosurgery

Published Open-Access

yes

Recommended Citation

Singh, Raj; Dayawansa, Samantha; Pham, Duy; et al., "Dosimetric Predictors of Toxicity for Brainstem Metastases and AVMs Treated With Stereotactic Radiosurgery: An International, Multi-Institutional Analysis" (2025). Faculty, Staff and Student Publications. 3844.
https://digitalcommons.library.tmc.edu/uthmed_docs/3844