Guideline Summary for WHO Grade IV Glioblastoma Management
Initial Surgical Management
- Maximal safe surgical resection should be performed first, provided that neurological function is not compromised; gross‑total resection is associated with improved survival compared with subtotal resection or biopsy alone. 1
- In right‑parietal tumors, aggressive resection is feasible while continuously monitoring language, sensory, and motor function because the dominant hemisphere is not involved. 1
Standard Chemoradiotherapy (Stupp Regimen)
Concurrent Phase
- Deliver focal radiotherapy to a total dose of 60 Gy in 2 Gy fractions, five days per week for six weeks (≈30 fractions). This dose is supported by level‑I evidence from randomized trials. 1
- Administer temozolomide 75 mg/m² orally each day throughout radiotherapy (up to 49 days). This concurrent schedule has demonstrated a significant survival benefit (hazard ratio 0.63). Level‑I evidence. 1
Adjuvant Phase
- Four weeks after radiotherapy, start adjuvant temozolomide 150 mg/m² on days 1–5 of a 28‑day cycle, escalating to 200 mg/m² from cycle 2 onward if hematologic criteria are met; continue for six cycles. Level‑I evidence. 1
Critical Molecular Testing
- Test tumor tissue for MGMT promoter methylation before or during therapy; methylation predicts a greater benefit from temozolomide. Level‑I evidence. 1
Supportive Care
Corticosteroids
- Use dexamethasone 8–16 mg/day only when clinically significant edema or neurological deficits are present; avoid prophylactic or prolonged steroid use after surgery or during radiotherapy. Level‑III evidence. 1
- Monitor blood glucose closely while patients receive steroids to detect hyperglycemia early. Level‑III evidence. 1
Seizure Management
- Initiate antiepileptic drugs (AEDs) only in patients who have experienced seizures; prophylactic AEDs are not recommended for seizure‑free patients. Level‑III evidence. 1
- Prefer third‑generation AEDs (e.g., levetiracetam, lamotrigine, pregabalin) over enzyme‑inducing first‑generation agents because the latter can interfere with chemotherapy metabolism. Level‑III evidence. 1
- Temozolomide does not interact with enzyme‑inducing AEDs, although other chemotherapeutic agents may. Level‑III evidence. 1
Age‑Specific Treatment Modifications
- Patients ≤ 70 years: Apply the full standard protocol (maximal resection + concurrent RT + temozolomide + adjuvant temozolomide). Level‑I evidence. 1
- Patients > 70 years: Consider hypofractionated radiotherapy (either 40 Gy in 15 fractions or 50 Gy in 28 fractions of 1.8 Gy) because it provides comparable control with less treatment burden. Level‑I evidence. 2
- Radiotherapy alone improves survival compared with best supportive care in patients > 70 years. Level‑I evidence. 2
- No randomized data support temozolomide in elderly patients with good performance status; exclusive temozolomide chemotherapy remains a proposed but unproven option. Level‑III evidence. 1
Radiotherapy Dose Limits and Unproven Therapies
- Do not exceed a total radiotherapy dose of 60 Gy; dose escalation has not shown survival benefit. Level‑I evidence. 2
- PCV chemotherapy (procarbazine, lomustine, vincristine) should be avoided for newly diagnosed glioblastoma because randomized trials showed no survival advantage. Level‑I evidence. 3
- Carmustine wafer implantation provides only marginal benefit and lacks comparative data against the standard temozolomide‑radiotherapy regimen; its routine use is not recommended. Level‑II evidence. 4
Management of Recurrent Disease
- There is no established standard chemotherapy for recurrent glioblastoma after temozolomide failure; treatment decisions should be individualized. Level‑III evidence. 1
- Enrollment in clinical trials is the preferred option for patients with recurrent disease, given the lack of proven systemic therapies. Level‑III evidence. 1
Glioblastoma Management
Classification and Diagnosis
- The World Health Organization recommends classifying glioblastoma according to the most recent WHO Classification of Tumors of the Central Nervous System with molecular testing for IDH mutation status, MGMT promoter methylation, and other key genetic markers 5, 6
- Glioblastoma is classified as WHO grade 4, the highest grade in the WHO classification system 7, 8
- Modern classification requires integration of histological features and molecular markers 5, 7, 9
- Key molecular markers that must be tested include IDH mutation status, MGMT promoter methylation status, 1p/19q codeletion status, TERT promoter mutations, EGFR amplification, and chromosome 7 gain/chromosome 10 loss (+7/-10 signature) 5, 7, 9
Standard Treatment
- The European Society for Medical Oncology recommends maximal safe surgical resection as the initial approach whenever feasible 8, 10
- Gross total resection improves survival outcomes compared to subtotal resection or biopsy 10
- Standard fractionated radiotherapy (60 Gy in 30 fractions of 2 Gy) is recommended after resection or biopsy 8, 10
- Concurrent and adjuvant temozolomide is the standard chemotherapy regimen 8, 10
- MGMT promoter methylation status predicts benefit from temozolomide therapy 5, 9
Prognostic Factors
- Key favorable prognostic factors include younger age, good performance status, extent of resection, MGMT promoter methylation, and IDH mutation 5, 8, 9