Faculty, Staff and Student Publications
Publication Date
9-1-2022
Journal
Neuro-Oncology
DOI
10.1093/neuonc/noac044
PMID
35157767
PMCID
PMC9435496
PubMedCentral® Posted Date
2-14-2022
PubMedCentral® Full Text Version
Post-print
Abstract
Background: Brainstem toxicity after radiation therapy (RT) is a devastating complication and a particular concern with proton radiation (PBT). We investigated the incidence and clinical correlates of brainstem injury in pediatric brain tumors treated with PBT.
Methods: All patients < 21 years with brain tumors treated with PBT at our institution from 2007-2019, with a brainstem Dmean >30 Gy and/or Dmax >50.4 Gy were included. Symptomatic brainstem injury (SBI) was defined as any new or progressive cranial neuropathy, ataxia, and/or motor weakness with corresponding radiographic abnormality within brainstem.
Results: A total of 595 patients were reviewed and 468 (medulloblastoma = 200, gliomas = 114, ependymoma = 87, ATRT = 43) met our inclusion criteria. Median age at RT was 6.3 years and median prescribed RT dose was 54Gy [RBE]. Fifteen patients (3.2%) developed SBI, at a median of 4 months after RT. Grades 2, 3, 4, and 5 brainstem injuries were seen in 7, 5, 1, and 2 patients respectively. Asymptomatic radiographic changes were seen in 51 patients (10.9%). SBI was significantly higher in patients with age ≤3 years, female gender, ATRT histology, patients receiving high-dose chemotherapy with stem cell rescue, and those not receiving craniospinal irradiation. Patients with SBI had a significantly higher V50-52. In 2014, our institution started using strict brainstem dose constraints (Dmax ≤57 Gy, Dmean ≤52.4 Gy, and V54≤10%). There was a trend towards decrease in SBI from 4.4% (2007-2013) to 1.5% (2014-2019) (P = .089) without affecting survival.
Conclusion: Our results suggest a low risk of SBI after PBT for pediatric brain tumors, comparable to photon therapy. A lower risk was seen after adopting strict brainstem dose constraints.
Keywords
Brain Neoplasms, Brain Stem, Cerebellar Neoplasms, Child, Child, Preschool, Female, Humans, Proton Therapy, Protons, Radiation Injuries, Radiotherapy Dosage, brainstem injury, pediatric cancer, proton therapy, radiation
Published Open-Access
yes
Recommended Citation
Upadhyay, Rituraj; Liao, Kaiping; Grosshans, David R; et al., "Quantifying the Risk and Dosimetric Variables of Symptomatic Brainstem Injury After Proton Beam Radiation in Pediatric Brain Tumors" (2022). Faculty, Staff and Student Publications. 4461.
https://digitalcommons.library.tmc.edu/uthgsbs_docs/4461
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