Bioimpedance in neurosurgery for tumor margin delineation

Area of Science:

• Neurosurgery
• Biomedical Engineering
• Oncology

Background:

• Brain tissue exhibits measurable electrical impedance differences due to cellular composition and fluid content.
• Bioimpedance (BI) offers real-time intraoperative data for guiding tumor resection, complementing existing imaging modalities.
• BI has emerged as a promising tool for enhancing surgical precision in glioma and other brain lesion resections.

Purpose of the Study:

• To review current evidence on the reliability of bioimpedance in delineating tumor margins during neurosurgery.
• To evaluate the differences in electrical properties between normal and pathological brain tissues.
• To assess the potential for routine clinical application of bioimpedance in neuro-oncology.

Main Methods:

• Systematic review of key studies published between 2014 and 2024.
• Focus on in vivo bioimpedance measurements in brain tissue and oncology applications.
• Literature search conducted on PubMed and Scopus using keywords such as bioimpedance, brain tumor margins, glioma surgery, and intraoperative monitoring.

Main Results:

• Tumor tissue demonstrates significantly different resistivity compared to surrounding white and gray matter.
• Studies report distinct resistivity values for white matter, peritumoral edema, low-grade gliomas, and high-grade gliomas.
• Consistent and significant electrical differences between physiological brain tissue and tumor tissue were observed across studies.

Conclusions:

• Methodological heterogeneity and lack of standardization currently limit the routine clinical application of bioimpedance.
• Standardized protocols and large-scale validation studies are essential for integrating bioimpedance into surgical decision-making.
• Further research is needed to facilitate bioimpedance's role in determining the extent of tumor resection.