Butterfly gliomas: a time for stratified management?

Butterfly glioblastomas (bGBM) are a rare subset of WHO grade IV tumours that carry a poor prognosis with a median survival ranging between 3.3 to 6 months. Given their poor prognosis, there is debate over whether histological diagnosis with a biopsy or any surgical or oncological intervention alters disease progression. With this in mind, we reviewed our experience as a high-volume unit to evaluate management decisions and outcomes. A retrospective analysis was undertaken (January 2009 to June 2021) of the electronic patient records of a large neurosurgical centre. We assessed patient demographics, initial clinical presentation, tumour characteristics, clinical management and overall survival (Kaplan-Meier estimator, log-rank analysis and cox proportional hazard analysis). Eighty cases of bGBM were identified. These patients were managed with biopsy ± adjuvant therapy (36), with radiotherapy alone without biopsy (3), or through surgical resection (3). Thirty-eight cases of suspected bGBM were managed conservatively, receiving no oncological treatment or surgical resection/biopsy for histological diagnosis. Those managed conservatively and with radiotherapy without biopsy were diagnosed at neuro-oncology multidisciplinary meeting (MDT) based on clinical presentation and radiological imaging. No significant difference in survival was seen between conservative management compared with single adjuvant treatment (p = 0.69). However, survival was significantly increased when patients received dual adjuvant chemoradiotherapy following biopsy or resection (p = 0.002). A Cox Proportional Hazards model found that survival was significantly impacted by the oncology treatment (p < 0.001), but was not significantly related to potential confounding variables such as the patient's age (p = 0.887) or KPS (p = 0.057). Butterfly glioblastoma have a poor prognosis. Our study would suggest that unless a patient is planned for adjuvant chemoradiotherapy following biopsy, they should be managed conservatively. This avoids unnecessary procedural interventions with the associated morbidities and costs.