REMIT: Reirradiation of Diffuse Midline Glioma Patients -A Nordic Society of Paediatric Haematology and Oncology Feasibility Study.

Diffuse midline glioma (DMG) continues to be an aggressive brain stem cancer among children and young adults. It has a dismal prognosis, with less than 10% of patients alive two years after diagnosis. Radiotherapy has been demonstrated to be effective, albeit transient. Hence, radiotherapy is considered a cornerstone in the treatment. Reirradiation has, in retrospective studies, shown promising overall survival and palliative effect, but no pan-European consensus for reirradiation exists. The REMIT (Reirradiation of diffuse Midline glioma paTients) protocol evaluates safety and the palliative efficacy of reirradiation of patients with DMG (clinicaltrials.gov NCT06093165). Patients included in the protocol will be followed with 1) performance status (Karnofsky or Lansky), 2) toxicity monitored with Common Terminology Criteria for Adverse Events (CTCAE), 3) motor and functioning skill with PEDI-CAT (The Pediatric Evaluation of Disability Inventory) and 4) quantification of corticosteroid use. Furthermore, the impact on quality of life and well-being will be assessed qualitatively with interviews as well as with the Pediatric Quality of Life Inventory (PedsQl) Cancer Module questionnaire. The protocol also includes dose accumulation and contouring studies to assess standardization as well as a prescreening log to address selection bias of patients. The safety and palliative efficacy of reirradiation in DMG will be prospectively evaluated, including qualitative patient reported outcomes, through the REMIT protocol. REMIT is planned to open for inclusion in 2024.