Re-irradiation for children with diffuse intrinsic pontine glioma and diffuse midline glioma.

in Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology by Nisha Shariff, Alejandro S Moreno, Julie Bennett, Vijay Ramaswamy, Anirban Das, Anthony P Liu, Annie Huang, Uri Tabori, Cynthia Hawkins, Peter Dirks, Eric Bouffet, Dana M Keilty, Barbara-Ann Millar, David C Hodgson, Derek S Tsang

TLDR

  • The study found that re-irradiation (giving the same cancer treatment again) can improve survival and reduce symptoms in children with recurrent DIPG and DMG.
  • However, more research is needed to identify biomarkers that can help select the best patients for re-irradiation and to optimize treatment strategies.

Abstract

Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are incurable brain malignancies. In this study, we report one of the largest known single-institution cohorts of DIPG/DMG patients undergoing re-irradiation (RT2) to evaluate its effect on survival. Children aged less than 18 years treated for DIPG/DMG with initial fractionated photon radiotherapy (RT1) and had subsequent recurrence were retrospectively reviewed. Patients treated with or without RT2 were compared. The primary outcomes were overall survival (OS) from time of recurrence after RT1, and from start of RT2 (for the RT2 group). A total of 118 children were included, 39 of whom received RT2. Children treated with RT2 had superior OS, with 6-month OS of 66 % vs 22 % in those who did not undergo RT2 (p < 0.0001). Median survivals were 6.9 months for the RT2 group vs 2.7 months for RT1 only. Median time from RT1 to RT2 was 7.7 months; patients with a greater than 1-year latent time between RT1 and RT2 had longer OS from start of RT2 (median 10.9 months vs 5.5 months, p = 0.023). 61 % of those treated with RT2 experienced improvement of neurologic symptoms post-RT2. Multivariate analysis identified younger age, adverse imaging findings on the 4-week post-RT1 reassessment MRI (including pseudoprogression), and the absence of RT2 as poor prognostic factors for OS. Re-irradiation was associated with improved survival and neurological recovery in children with recurrent DIPG and DMG. There is a need to identify novel biomarkers to better select patients who respond best to RT2.

Overview

  • The study evaluates the effect of re-irradiation (RT2) on survival in children with recurrent diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG).
  • The study included a cohort of 118 children with DIPG/DMG who received initial fractionated photon radiotherapy (RT1) and had subsequent recurrence. Of these, 39 received RT2.
  • The primary outcomes were overall survival (OS) from time of recurrence after RT1 and from the start of RT2 (for the RT2 group).

Comparative Analysis & Findings

  • Children treated with RT2 had superior OS, with a 6-month OS of 66% compared to 22% in those who did not undergo RT2 (p < 0.0001).
  • The median survival time was 6.9 months for the RT2 group vs 2.7 months for the RT1-only group.
  • Multivariate analysis identified younger age, adverse imaging findings on post-RT1 reassessment MRI, and the absence of RT2 as poor prognostic factors for OS.

Implications and Future Directions

  • The study suggests that re-irradiation may be an effective treatment strategy for recurrent DIPG and DMG, with improved survival and neurological recovery.
  • Future studies should aim to identify novel biomarkers to better select patients who respond best to re-irradiation.
  • The findings also highlight the importance of optimizing imaging and treatment strategies to improve outcomes for children with these aggressive brain tumors.
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