Brainstem Toxicity Following Proton Beam Radiation Therapy in Pediatric Brain Tumors: A Systematic Review and Meta-Analysis.

Simple Summary: Proton beam radiation therapy is one of the major treatment modalities used for cancer treatment, including brain tumors. This treatment modality is distinct from other radiation options because of its ability to deliver radiation to tumor targets while sparing healthy tissue. Brainstem toxicity is a rare but important complication can arise due to exposure to radiation; hence, in this systematic review and meta-analysis, we aimed to explore the risk of brainstem toxicity in pediatric brain tumor patients undergoing proton beam radiation, focusing on quantifying its incidence and severity. Eleven articles were considered eligible in our study, and the results yielded an overall brainstem toxicity incidence of 1.8%, ranging in severity, with Grade 1 brainstem toxicity (asymptomatic) being the most common. This study revealed a low incidence of symptomatic brainstem toxicity and related mortality among pediatric brain tumor patients undergoing proton beam radiation, which could support the idea of it having a good toxicity profile and possibly re-enforces the need for more comprehensive primary studies regarding this radiation modality in brain tumor patients to uncover unknowns and help us understand the grey areas of this topic. Background: Proton beam radiation therapy (PBRT) is an advanced cancer treatment modality that utilizes the distinctive physical properties of protons to precisely deliver radiation to tumor targets while sparing healthy tissue. This cannot be obtained with photon radiation. In this systematic review and meta-analysis, we aimed to comprehensively assess the risk of brainstem toxicity in pediatric brain tumor patients undergoing PBRT. Methods: With adherence to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a predetermined search strategy was used to identify eligible articles from PubMed, Web of Science, Scopus, and Cochrane Library through July 2024. Results: The current study included a total of 11 eligible articles. The pooled prevalence of patients who suffered from brainstem toxicity was 1.8% (95% CI: 1%, 2.6%). The pooled prevalences of patients with Grade 1 to Grade 5 brainstem toxicity were found to be 10.6% (95% CI: 8.8%, 30%), 1.5% (95% CI: 0.6%, 2.5%), 0.7% (95% CI: 0.3%, 1.1%), 0.4% (95% CI: 0.1%, 0.7%), and 0.4% (95% CI: 0.1%, 0.8%), respectively, with an overall pooled prevalence of 0.7% (95% CI: 0.4%, 1%). Conclusions: This study revealed a relatively low incidence of symptomatic brainstem toxicity and its related mortality in the pediatric population undergoing PBRT. However, further research is encouraged to study the broader effects of PBRT and to explore various factors that may influence the risk of brainstem toxicity in patients treated with PBRT. [ABSTRACT FROM AUTHOR]