Clinical Report: Impact of Resection Extent on Survival in Brain Metastases Surgery

Overview

This study evaluated 374 adults undergoing surgical resection of single brain metastases, comparing outcomes between gross total resection and subtotal resection. Findings suggest that while gross total resection is preferred, its impact on overall survival remains uncertain, with potential risks of neurological damage.

Background

Brain metastases are the most common malignant brain tumors in adults, causing significant morbidity and mortality with median survival around 5 months post-diagnosis. Treatment options include radiotherapy, systemic therapy, and surgery, often combined based on patient and tumor characteristics. Surgery is typically indicated for limited lesions, symptomatic mass effect, or uncertain diagnosis, aiming for gross total resection. However, accurately assessing resection extent intraoperatively is challenging, and the survival benefit of gross total versus subtotal resection in brain metastases is debated.

Data Highlights

A retrospective review of 374 adults undergoing craniotomy for single brain metastasis at Oslo University Hospital from 2011 to 2018 was conducted. Gross total resection was defined by absence of visible residual tumor on postoperative MRI within 12–48 hours. Postoperative complications and neurological deficits were recorded within 30 days. ECOG performance status and extracranial disease status were classified preoperatively. The study excluded patients with multiple metastases or leptomeningeal dissemination.

Key Findings

• Gross total resection was achieved when no residual tumor was visible on postoperative MRI within 12–48 hours.
• Surgeons may overestimate resection extent intraoperatively, with up to 40% discrepancy compared to postoperative MRI.
• Previous studies show conflicting results: some report longer survival and delayed local recurrence with gross total resection, others find no survival difference when adjuvant therapy is given.
• In this cohort, the impact of gross total versus subtotal resection on median overall survival was investigated to clarify clinical significance.
• Postoperative neurological deficits and complications were systematically recorded to assess risks associated with more extensive resection.

Clinical Implications

Surgeons should aim for gross total resection when feasible, but must balance this goal against the risk of neurological injury. Postoperative MRI within 72 hours is essential to accurately assess resection extent. Multimodal treatment including adjuvant radiotherapy and systemic therapy remains critical. Further research is needed to define which patients benefit most from aggressive surgical resection.

Conclusion

While gross total resection is generally preferred in managing single brain metastases, its definitive impact on survival remains unclear. Careful surgical planning and postoperative assessment are vital to optimize outcomes and minimize neurological harm.

References

1. Jünger et al. 2021 -- Extent of Resection and Survival in Brain Metastases
2. Oslo University Hospital Brain Tumor Register 2011-2018 Data
3. Clinical Guidelines on Brain Metastases Management, 2020