Re-irradiation of anaplastic meningioma: higher dose and concomitant Bevacizumab may improve progression-free survival.

in Radiation oncology (London, England) by Ory Haisraely, Alicia Taliansky, Maayan Sivan, Yaacov Lawerence

TLDR

  • The study looked at patients with a rare and aggressive type of brain tumor called anaplastic meningioma. These patients had already undergone surgery and radiation treatment, but their tumors came back. The study analyzed how re-irradiation with higher doses and a drug called Bevacizumab could improve outcomes and reduce toxicity. The study also looked at how a genetic mutation called CDKN2A homozygote deletion could affect the success of re-irradiation. The study found that higher doses of re-irradiation with Bevacizumab improved progression-free survival and reduced toxicity. CDKN2A homozygote deletion correlated with a higher risk of local failure. Symptomatic radiation necrosis occurred in 20.5% of cases, but its incidence was lower with concomitant Bevacizumab treatment. The study suggests that re-irradiation with higher doses and Bevacizumab could be a viable option for recurrent anaplastic meningioma, and individualized treatment approaches are necessary.

Abstract

Anaplastic meningiomas, categorized as WHO grade 3 tumors, are rare and highly aggressive, accounting for 1-2% of all meningioma cases. Despite aggressive treatment, including surgery and Radiation, they exhibit a high recurrence rate and poor survival outcomes. The aggressive histopathological features emphasize the urgent need for effective management strategies. A retrospective multi-institutional analysis was conducted on patients with recurrent anaplastic meningioma who underwent re-irradiation between 2017 and 2023. Clinical, dosimetric, and outcome data were collected and analyzed, focusing on local control, progression free survival and treatment-related adverse events. Thirty-four cases were analyzed, with a median follow-up 11 months after re-irradiation. Progression-free survival at 12 months was 61.9%, with higher doses correlating with better outcomes. Concomitant Bevacizumab improves progression-free survival and reduces the risk of radiation necrosis. CDKN2A homozygote deletion correlated with a higher risk of local failure. Symptomatic radiation necrosis occurred in 20.5% of cases, but its incidence was lower with concomitant Bevacizumab treatment. Re-irradiation presents a viable option for recurrent anaplastic meningioma despite the associated risk of radiation necrosis. Higher doses with concomitant Bevacizumab improve clinical outcomes and reduce toxicity. Individualized treatment approaches are necessary, emphasizing the importance of further research to refine management strategies for this challenging disease.

Overview

  • The study focuses on recurrent anaplastic meningioma patients who underwent re-irradiation between 2017 and 2023. The primary objective is to analyze the clinical, dosimetric, and outcome data of these patients, focusing on local control, progression-free survival, and treatment-related adverse events. The study aims to identify effective management strategies for this aggressive disease.

Comparative Analysis & Findings

  • Higher doses of re-irradiation were associated with better outcomes, including progression-free survival. Concomitant Bevacizumab treatment improved progression-free survival and reduced the risk of radiation necrosis. CDKN2A homozygote deletion correlated with a higher risk of local failure. Symptomatic radiation necrosis occurred in 20.5% of cases, but its incidence was lower with concomitant Bevacizumab treatment.

Implications and Future Directions

  • The study highlights the importance of individualized treatment approaches for recurrent anaplastic meningioma, emphasizing the need for further research to refine management strategies. Higher doses with concomitant Bevacizumab show promise in improving clinical outcomes and reducing toxicity. Future studies should explore the use of other targeted therapies and individualized dosimetry to further optimize treatment outcomes.
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