What is the initial treatment approach for a patient diagnosed with glioblastoma?

Initial Treatment Approach for Glioblastoma

The standard initial treatment for glioblastoma consists of maximal safe surgical resection followed by fractionated focal radiotherapy (60 Gy in 30 fractions) with concurrent temozolomide chemotherapy and then adjuvant temozolomide. 1, 2, 3

Diagnostic and Initial Evaluation

• MRI of the brain is the preferred imaging modality for diagnosis and surgical planning
• Tissue diagnosis through biopsy or surgical resection is essential for confirming glioblastoma
• Molecular testing, particularly MGMT promoter methylation status, helps predict response to temozolomide 1

Surgical Management

• Transfer to a specialized neurosurgical center for evaluation and treatment 4
• Maximal safe surgical resection is the initial approach for:
  • Tumor debulking
  • Obtaining tissue for accurate diagnosis
  • Improving prognosis 4, 1
• Post-operative MRI should be performed within 24-48 hours to assess residual disease 4, 1

Adjuvant Treatment

Radiotherapy

• Begin within one month after surgery 4
• Standard dose: 60 Gy delivered in 30 fractions (2 Gy per fraction) 4
• For elderly patients (>70 years) or those with poor performance status:
  • Consider shorter hypofractionated regimens (e.g., 40 Gy in 15 fractions) 4, 1

Chemotherapy

• Temozolomide is the standard chemotherapeutic agent for glioblastoma 2, 3
• Administration schedule:
  • Concurrent phase: 75 mg/m² daily, 7 days per week during radiotherapy
  • Adjuvant phase: 150-200 mg/m² for 5 days during each 28-day cycle for 6 cycles 1, 3
• Temozolomide with radiation therapy has demonstrated significant improvement in median survival (14.6 months vs. 12.1 months) and 2-year survival (26.5% vs. 10.4%) compared to radiotherapy alone 3

Prognostic Factors and Treatment Modifications

• Better prognosis is associated with:
  • Younger age (<50 years)
  • Good performance status
  • Extensive tumor resection
  • MGMT promoter methylation 4, 1
• For patients with poor prognostic factors (advanced age, poor performance status, multiple comorbidities):
  • Consider modified treatment approaches or palliative care 4

Supportive Care

• Prophylaxis against Pneumocystis pneumonia during concurrent chemoradiotherapy 1
• Anticoagulant prophylaxis with low-molecular weight heparin and compression stockings to prevent thromboembolic complications 4, 1
• Regular monitoring of blood counts during treatment 1

Follow-up and Monitoring

• Brain MRI every 3 months for the first 2 years 1
• Be aware of pseudoprogression (radiographic worsening 4-8 weeks after radiation) which may mimic tumor progression 1

Treatment Challenges and Considerations

• Despite optimal treatment, median survival remains around 14-15 months 5, 6
• Most patients will experience recurrence within 2 years despite adequate treatment 5
• Clinical trials should be considered for eligible patients, particularly at recurrence 1

The combination of maximal safe resection, radiotherapy, and temozolomide represents the most effective initial approach for glioblastoma based on level I evidence, with significant improvements in survival outcomes compared to previous treatment standards 3.