What is the significance of a butterfly glioma and how and when is it treated?

From the Guidelines

A butterfly glioma is a high-grade brain tumor that requires prompt and aggressive treatment, typically involving a multidisciplinary approach with surgical resection, radiation therapy, and chemotherapy, due to its poor prognosis and significant impact on morbidity, mortality, and quality of life. The significance of a butterfly glioma lies in its aggressive nature, poor prognosis, and challenging treatment options. Treatment typically involves a multidisciplinary approach beginning with surgical resection when possible, though complete removal is often impossible due to the tumor's location across both hemispheres and infiltration into critical brain structures.

Following surgery, standard treatment includes radiation therapy (typically 60 Gy delivered in 30 fractions over 6 weeks) combined with concurrent temozolomide chemotherapy (75 mg/m² daily during radiation), followed by adjuvant temozolomide (150-200 mg/m² for 5 days every 28 days for 6-12 cycles) as recommended by the most recent guidelines 1. For elderly patients or those with poor performance status, hypofractionated radiation schedules may be used.

Key considerations in the treatment of butterfly gliomas include:

• The importance of a multidisciplinary approach to care
• The role of surgical resection in debulking the tumor and obtaining tissue for diagnosis
• The use of radiation therapy and chemotherapy, including temozolomide, in the treatment of these tumors
• The need for individualized treatment planning based on patient performance status, age, and other factors

Treatment is initiated promptly after diagnosis and stabilization of symptoms, which may include seizures, headaches, cognitive changes, and motor deficits. Despite aggressive treatment, prognosis remains poor with median survival typically ranging from 12-15 months, as these tumors are usually glioblastomas (WHO grade IV) with characteristic genetic alterations like IDH-wildtype status that confer resistance to treatment 1. The management of patients with suspected glioma should be discussed with a multidisciplinary neuro-oncology team 1, and treatment strategies should be guided by the most recent and highest-quality evidence available 1.

From the Research

Definition and Significance of Butterfly Glioma

• Butterfly glioma, also known as butterfly glioblastoma (bGBM), is a rare and aggressive type of brain tumor that crosses the corpus callosum and involves both cerebral hemispheres 2, 3, 4, 5, 6.
• The tumor is characterized by its butterfly-shaped appearance on MRI scans due to its bihemispheric involvement and invasion of the corpus callosum 3, 4, 6.

Treatment Options and Outcomes

• Treatment options for bGBM include surgical resection, biopsy, radiation therapy, and chemotherapy 2, 3, 4, 5, 6.
• Studies have shown that surgical resection can improve survival outcomes for patients with bGBM, especially when combined with adjuvant chemoradiation 3, 4, 6.
• The extent of resection is a significant prognostic factor, with a minimum extent of resection of 86% required to observe survival benefits 3.
• Radiation therapy, including hypofractionated radiation therapy with or without temozolomide, is also a common treatment strategy for bGBM 5.
• Overall, the prognosis for bGBM is poor, with a median overall survival of less than 6 months, but long-term survival is possible with aggressive treatment approaches 2, 5.

Timing of Treatment

• Treatment for bGBM is typically initiated shortly after diagnosis, with the goal of improving survival outcomes and reducing symptoms 2, 3, 4, 5, 6.
• The timing of treatment may vary depending on the individual patient's condition, tumor characteristics, and treatment goals 2, 3, 4, 5, 6.

Factors Affecting Treatment Outcomes

• Age, Karnofsky Performance Status, preoperative tumor volume, postoperative tumor volume, and extent of resection are significant prognostic factors for bGBM 3, 4.
• Molecular characteristics, such as BRAF mutations, may also impact treatment outcomes and response to therapy 2.
• Adjuvant therapy, including chemotherapy and radiation therapy, can improve survival outcomes for patients with bGBM 3, 4, 5, 6.