Management of Optic Pathway Glioma: A Systematic Review and Meta-Analysis

Simple Summary In the current study, we systematically reviewed the literature regarding the management of optic pathway glioma (OPG). This review will analyze demographics, information regarding the type of treatment, radiological and clinical (visual) outcomes, and also complications. Of the 105 eligible studies, a total of 4177 patients underwent different therapeutic modalities, including surgery, radiotherapy, and chemotherapy. The mean age was 8.17 years, and the gender ratio was 97 males per 100 females. Based on the available data, the mean follow-up was 98.6 months, and 48.7% of the patients were known cases of neurofibromatosis type1. According to the Dodge classification, 1104, 941, and 1353 tumors were D-1, D-2, and D-3, respectively. The toxicity induced by either chemo- or radiotherapy was the most common complication, followed by ophthalmologic complications rather than visual acuity exacerbation. Small sample sizes in studies that compare different therapeutic modalities for OPG treatment, heterogeneity in multiple parameters including tumor locations, patients' age distribution who received treatment, patients lost to follow-up in many studies, lack of high-power studies, and insufficient power to adequately prove the efficacy or safety profile of different therapeutic modalities are all possible limitations of this systematic review. Moreover, in order to reduce the versatility between studies, we have considered all different types of surgical procedures, distinct chemotherapy (CT) regimens, and separate ways to deliver irradiation in OPG patients as surgery, CT, and radiotherapy (RT), respectively. This assumption was made since available data were neither representative of actual therapeutic modalities nor provided an opportunity to conduct sub-group analysis. Additionally, since children's visual assessments are notoriously recalcitrant, it might be obscure the results of visual acuity in pediatrics. Background: OPG accounts for 3-5% of childhood central nervous system (CNS) tumors and about 2% of pediatric glial lesions. Methods: Article selection was performed by searching PubMed, Web of Science, and Cochrane databases. Results: The pooled mortality rate was 0.12 (95%CI 0.09-0.14). Due to the unrepresentative data, improved and not changed outcomes were classified as favorable outcomes and worsened as unfavorable. Meta-analyses were performed to determine the rate of clinical and radiological favorable outcomes. In terms of visual assessment, the pooled rate of a favorable outcome in chemotherapy, radiotherapy, and surgery was 0.74, 0.81, and 0.65, respectively, and the overall pooled rate of the favorable outcome was 0.75 (95%CI 0.70-0.80). In terms of radiological assessment, the rate of a favorable outcome following chemotherapy, radiotherapy, and surgery was 0.71, 0.74, and 0.67, respectively, and the overall pooled rate of the favorable outcome is 0.71 (95%CI 0.65-0.77). The subgroup analysis revealed no significant difference in the rate of clinical and radiological favorable outcomes between the different treatment modalities (p > 0.05). Conclusion: Our analyses showed that each therapeutic modality represents viable treatment options to achieve remission for these patients.