From the Guidelines
The treatment of WHO grade 3/4 astrocytoma in the thalamus and brainstem should involve a multimodal approach with maximal safe surgical resection, followed by radiation therapy and chemotherapy, as outlined in the EANO guidelines 1. The standard treatment regimen includes maximal safe resection when possible, followed by adjuvant radiation therapy (typically 60 Gy in 30 fractions over 6 weeks) with concurrent temozolomide chemotherapy (75 mg/m² daily during radiation), then maintenance temozolomide (150-200 mg/m² for 5 days every 28-day cycle) for 6-12 months.
- For tumors in eloquent areas like the thalamus and brainstem, stereotactic biopsy may be performed instead of resection to obtain tissue for diagnosis while minimizing neurological deficits.
- Corticosteroids (dexamethasone 4-16 mg/day in divided doses) are often used to manage peritumoral edema and associated symptoms.
- Supportive care including anticonvulsants for seizures, venous thromboembolism prophylaxis, and rehabilitation services are essential components of management. The prognosis for high-grade gliomas in these locations remains poor, with median survival typically ranging from 12-15 months for grade 4 (glioblastoma) and somewhat longer for grade 3 tumors, as noted in the guidelines 1. Treatment decisions should be individualized based on the patient's age, performance status, tumor characteristics, and molecular markers (such as IDH mutation and 1p/19q codeletion status), which significantly impact prognosis and potentially treatment response, as discussed in the EANO guidelines 1.
From the FDA Drug Label
Temozolomide capsules are indicated for the treatment of adult patients with: Newly diagnosed glioblastoma multiforme (GBM) concomitantly with radiotherapy and then as maintenance treatment. Refractory anaplastic astrocytoma patients who have experienced disease progression on a drug regimen containing nitrosourea and procarbazine.
The FDA drug label does not specifically address the treatment of WHO grade 3/4 Astrocytoma thalamus and brain stem. However, it does mention the treatment of refractory anaplastic astrocytoma.
- Key points:
- Temozolomide is used for the treatment of refractory anaplastic astrocytoma.
- The dosage for refractory anaplastic astrocytoma is 150 mg/m2 once daily for 5 consecutive days per 28-day treatment cycle 2.
- The label does not provide information on the treatment of WHO grade 3/4 Astrocytoma thalamus and brain stem.
- Clinical decision: Due to the lack of direct information, a conservative clinical decision would be to consult additional resources or expert opinions for the treatment of WHO grade 3/4 Astrocytoma thalamus and brain stem.
From the Research
Treatment Options for WHO Grade 3/4 Astrocytoma
- The treatment of WHO grade 3/4 astrocytoma, particularly in sensitive areas such as the thalamus and brain stem, is challenging due to the location and the aggressive nature of the tumor 3.
- Studies have shown that gross total resection, when possible, can improve outcomes, but the location of the tumor often limits the extent of surgical resection 3.
- Molecular genetic profiling and the use of ancillary treatments, such as chemotherapy and radiation therapy, may also play a role in the management of these tumors 3, 4.
Role of Temozolomide
- Temozolomide (TMZ) is a DNA alkylating agent that has been shown to be effective in the treatment of malignant astrocytomas, including anaplastic astrocytomas and glioblastomas 4.
- The addition of TMZ to radiation therapy has been shown to improve overall survival in patients with newly diagnosed glioblastoma, and its use has become a standard of care for this disease 4, 5.
- However, the evidence for the use of TMZ in the treatment of anaplastic astrocytomas is less clear, with some studies suggesting a survival benefit and others showing no significant improvement 6, 7.
Radiation Therapy
- Radiation therapy is a common treatment for astrocytomas, and its use in combination with TMZ has been shown to be effective in some cases 5, 7.
- The role of radiation therapy in the treatment of WHO grade 3/4 astrocytoma is well established, but the optimal dose and schedule of radiation therapy are still being studied 7.
Current Recommendations
- The current recommendations for the treatment of WHO grade 3/4 astrocytoma are based on the specific location and grade of the tumor, as well as the patient's overall health and performance status 3, 4, 5, 6, 7.
- A multidisciplinary approach, including surgery, radiation therapy, and chemotherapy, is often necessary to achieve the best possible outcomes for patients with these aggressive tumors 3, 4, 5, 6, 7.