Dose escalation with simultaneous integrated boost for un-methylated multiple glioblastoma

Area of Science:

• Neuro-oncology
• Radiation Oncology
• Clinical Trial Design

Background:

• Multifocal high-grade gliomas (HGG) are rare and associated with poor prognosis.
• Radiotherapy (RT) is a standard HGG treatment, but optimal dosing for multifocal disease is unclear.
• MGMT-unmethylated status influences treatment strategy in HGG.

Purpose of the Study:

• To evaluate the safety and efficacy of dose-escalated RT in patients with multiple MGMT-unmethylated HGG.
• To assess treatment response and adverse effects in this patient cohort.
• To establish feasibility for future prospective trials.

Main Methods:

• Retrospective chart review of 20 patients with multifocal MGMT-unmethylated HGG treated with dose-escalated RT (52.5 Gy in 15 fractions).
• Volumetric modulated arc therapy (VMAT) was used for treatment planning.
• Exclusion of MGMT-methylated patients and those receiving temozolomide (TMZ) concurrently with RT.

Main Results:

• All 20 patients completed dose-escalated radiotherapy without acute adverse effects.
• Six-month progression-free survival (PFS) was 85% by RANO criteria.
• Dosimetry and treatment response were evaluated.

Conclusions:

• Dose-escalated radiotherapy is a safe and feasible treatment option for multiple MGMT-unmethylated HGG.
• Promising PFS results warrant validation in larger prospective studies.
• This approach may improve outcomes for a subset of HGG patients.