Comparing the Recurrence Patterns of Reduced-Margins vs. RTOG-Protocol in Adjuvant Chemoradiation of High-Grade...

Area of Science:

• Neuro-oncology
• Radiation Oncology
• Clinical Trials

Background:

• Adjuvant radiotherapy is standard for high-grade gliomas (HGGs) post-resection.
• The optimal clinical target volume (CTV) margin for radiotherapy is debated.
• This study assessed a reduced CTV margin's safety and efficacy in HGG patients.

Purpose of the Study:

• To compare progression-free survival (PFS), overall survival (OS), and recurrence patterns between standard (2-cm) and reduced (1-cm) CTV margins in HGG radiotherapy.
• To evaluate the safety and feasibility of reduced CTV margins in HGG treatment.

Main Methods:

• A multicenter, phase III randomized clinical trial.
• 258 patients with newly diagnosed WHO-grade 3 or 4 gliomas were randomized.
• Intervention group received a 1-cm CTV margin; control group received a 2-cm CTV margin.

Main Results:

• Median PFS was 15 months (1-cm margin) vs. 19 months (2-cm margin) (p=0.121).
• Median OS was 22 months (1-cm margin) vs. not reached (2-cm margin) (p=0.057).
• Recurrence patterns and imaging progression rates were similar between groups, with no increase in marginal failures for the reduced margin.

Conclusions:

• Reducing the CTV margin from 2 cm to 1 cm did not significantly alter PFS, OS, or recurrence patterns in HGG radiotherapy.
• Margin reduction is feasible and safe, even with 3D-CRT techniques.
• These results support the potential for optimizing radiotherapy planning in HGGs.