What is the standard treatment for glioblastoma?

Standard Treatment for Glioblastoma

The standard treatment for glioblastoma consists of maximal safe surgical resection followed by fractionated focal radiotherapy (60 Gy) with concomitant and adjuvant temozolomide chemotherapy, which has been proven to significantly improve survival compared to radiotherapy alone. 1, 2

Initial Management

Diagnosis and Evaluation

• MRI is the preferred imaging modality for diagnosis and follow-up 1
• Histological diagnosis through biopsy or tumor resection is essential, following the WHO classification 1
• Patients should be evaluated by a specialized multidisciplinary team 1

Surgical Management

• Surgery serves two critical purposes:
  • Obtaining tissue for histological diagnosis
  • Maximal tumor debulking to improve prognosis 1
• All patients should be transferred to a specialized center for surgery evaluation 1
• Optimal surgical resection should be attempted when technically feasible and when there is low risk of permanent neurological deterioration 1
• Post-operative MRI within 24-48 hours is recommended to assess residual disease 1

Post-Surgical Treatment

Radiotherapy

• Fractionated focal radiotherapy is the standard post-surgical treatment 1
• Standard dose: 60 Gy delivered in 30 fractions of 2 Gy per day over 6 weeks 1, 2
• For elderly patients or those with poor performance status, shorter hypofractionated regimens (e.g., 40 Gy in 15 fractions) are appropriate 1

Chemotherapy

• Temozolomide is the standard chemotherapeutic agent, administered in two phases 2, 3:
  1. Concomitant phase: 75 mg/m² daily during radiotherapy (42 days)
  2. Adjuvant phase: 150-200 mg/m² for 5 days every 28 days for 6 cycles
• This regimen has demonstrated a statistically significant improvement in median survival (14.6 months vs. 12.1 months) and 2-year survival rate (26.5% vs. 10.4%) compared to radiotherapy alone 2, 3
• MGMT gene promoter methylation status may help select patients likely to benefit from temozolomide 1

Management of Recurrent Disease

For recurrent glioblastoma, treatment options include:

• Repeat surgery in selected patients 1
• Systemic chemotherapy, particularly for patients who haven't received prior chemotherapy 1
• Local chemotherapy, including implantation of carmustine-impregnated wafers (BCNU polymer) 1
• Re-irradiation using specialized techniques in selected cases 1
• Palliative care without specific anticancer treatment 1

Prognostic Factors

Better prognosis is associated with:

• Lower tumor grade
• Good performance status
• Intact neurological function
• Successful tumor resection
• Age <50 years 1
• MGMT gene promoter methylation 1

Common Pitfalls and Caveats

• Despite optimal treatment, virtually all glioblastomas recur, with median survival around 14.6 months 3, 4
• Delaying post-surgical treatment beyond one month may negatively impact outcomes; additional treatment should be started within a month of surgery 1
• Thromboembolism occurs frequently in glioblastoma patients and requires vigilant surveillance, prevention, and treatment 1
• Pneumocystis pneumonia prophylaxis is required during temozolomide plus radiotherapy treatment, regardless of lymphocyte count 2
• Treatment toxicity must be carefully monitored, with grade 3-4 hematologic toxicity occurring in approximately 7% of patients receiving combined temozolomide and radiotherapy 3

The treatment of glioblastoma remains challenging despite advances in therapy, with ongoing research into targeted therapies, immunotherapy, and novel compounds that may improve outcomes in the future 5, 4, 6.