Advanced imaging and localization techniques in brain tumor resection: A review for precision tumor removal

Brain tumors are one of the most dangerous cancers with serious effects on human health. The primary treatment approach involves a combination of surgery, supplemented by postoperative radiotherapy. The growth pattern of malignant tumor is typically infiltrative, posing a challenge in visually distinguishing the tumor from the surrounding normal brain tissue during surgery. In order to mitigate the risk of potential neurological damage, an increasing number of imaging and localization techniques and devices are being employed. Commonly used preoperative functional neuroimaging techniques, such as magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS), have proven to be powerful tools in neurosurgery. MRI aids in visualizing important functional areas involved in the tumor as well as the conduction pathways, and TMS assists in assessing cortical function. This enhanced preoperative information contributes to refining surgical planning and reduced risks in the surgery. The application of intraoperative functional neuroimaging techniques (neuronavigation (NN), intraoperative ultrasound (IOUS), fluorescence guided technique (FGT) and intraoperative neurophysiological monitoring (IONM)), has improved the gross total removal (GTR) of glioma in functional brain regions. NN, IOUS and FGT enable real-time exploration of tumor structures, providing valuable guidance for resection. Concurrently, IONM is employed to highlight the relationship between tumor and the functional cortex, with the aim of preventing or minimizing neurological deficits. These approaches ensure precision in tumor resection and help safeguard neurological function during surgery. This paper discusses the potential advantages and limitations of these techniques used in glioma surgery, and provides directions for the development of techniques.