Clinical Scorecard: Evaluation of Intra-cavitary Radiotherapy Techniques for Resected Brain Metastases: An In-depth Review with Individual Patient Data Meta-analysis of Intraoperative Radiotherapy (IORT) and Brachytherapy (IBT)

At a Glance

Key Highlights

• Brain metastases affect approximately 2% of all cancer patients and up to 12.1% of those with metastatic disease at diagnosis.
• Postoperative localized radiotherapy with IORT or IBT reduces treatment delays and limits radiation exposure to healthy brain tissue, achieving 1-year local control rates of 85–96%.
• IORT and IBT show promising efficacy and safety profiles in improving local control and preserving cognitive function compared to whole-brain radiotherapy.

Guideline-Based Recommendations

Diagnosis

• Histological confirmation of brain metastases prior to surgical resection.
• Use of imaging and clinical assessment to identify accessible lesions suitable for maximal safe resection.

Management

• Maximal safe surgical resection for symptomatic or accessible brain metastases.
• Adjuvant localized radiotherapy via IORT or IBT immediately during or after resection to reduce microscopic residual disease and recurrence.
• Avoidance of whole-brain radiotherapy when possible to minimize neurocognitive decline.

Monitoring & Follow-up

• Regular follow-up imaging to assess local control and detect distant brain failure.
• Monitoring for treatment-related toxicities including radiation necrosis and leptomeningeal disease.
• Assessment of wound healing and complications post-radiotherapy.

Risks

• Potential for radiation necrosis and leptomeningeal disease, though rates are reported and monitored.
• Risk of wound complications associated with intra-cavitary radiotherapy procedures.
• Selection bias and heterogeneity in study populations may affect outcome interpretation.

Patient & Prescribing Data

858 adult patients with resected brain metastases treated with IORT or IBT across 23 studies (1999–2024).

Both IORT and IBT demonstrate high 1-year local control rates (85–96%) with reduced treatment delays and preservation of cognitive function; patient selection and treatment modality should consider tumor characteristics and prior therapies.

Clinical Best Practices

• Employ maximal safe resection for accessible brain metastases to enable cytoreduction and histological diagnosis.
• Implement intraoperative or immediate postoperative localized radiotherapy (IORT or IBT) to target residual microscopic disease and improve local control.
• Prefer localized radiotherapy techniques over whole-brain radiotherapy to minimize neurocognitive side effects.
• Use standardized protocols for patient selection, treatment delivery, and follow-up to optimize outcomes and monitor for toxicity.
• Incorporate multidisciplinary evaluation including neurosurgery, radiation oncology, and neuro-oncology for individualized treatment planning.

References

• Brain metastases epidemiology and treatment overview
• Local control and radiotherapy modalities in brain metastases
• NIH Quality Assessment Tool for observational cohort and cross-sectional studies
• Guyot’s method for reconstructing individual patient data from Kaplan-Meier curves
• PRISMA guidelines for systematic reviews