When a malignant brain tumor invades an area responsible for important neurological functions, the surgeon has to weigh resection against preservation. How far should the resection go? Which areas are responsible for the patient's language, cognition and movement? These are things the operation itself has to establish.
Kuo-Chen Wei, an attending neurosurgeon at Linkou Chang Gung Memorial Hospital, and the hospital's brain tumor team use awake craniotomy, electrical stimulation mapping and real-time functional testing to judge the resection margin and pursue the maximal safe resection.
Between 2013 and 2025 the team accumulated 672 awake procedures, reporting a long-term neurological deficit rate of 5.6%. Beyond surgery, the team also works on the problem of the blood-brain barrier limiting drug delivery, through research on focused ultrasound and combination therapy.
Every patient differs in tumor location, extent of invasion and functional status. Before surgery, neurosurgery assesses how the tumor relates to brain function, while neurology, rehabilitation and psychiatry contribute neuropsychological, language and mood assessments to establish the patient's baseline.
During surgery, the anaesthetic team manages pain control and the sleep-wake sequence while assessors run cognitive and motor testing. The surgeon judges the extent of resection from cortical and subcortical stimulation mapping, neurophysiological monitoring and the patient's real-time responses; what is monitored is adjusted patient by patient.
The procedure requires several specialties to work in concert at the same moment. Since 2017 the team has standardised the awake craniotomy workflow, planning where the operating surgeon, assessors and anaesthetic staff and their equipment sit in the theatre, and linking pre- and post-operative functional assessment.
672 awake procedures between 2013 and 2025, with a long-term post-operative neurological deficit rate of 5.6%.
Team figures - follow-up data for this series of awake procedures
Among the intraoperative tools, MRI provides dynamic imaging, 5-ALA fluorescence helps identify tumor tissue, and functional monitoring helps identify critical functional areas.
Imaging and fluorescence support the identification of tumor; mapping, monitoring and real-time testing support the preservation of function. The use of intraoperative MRI and 5-ALA is tailored to each patient.
After surgery the team follows neurological and language function and records neuropsychological assessment, brain imaging, treatment response and survival status. The 5.6% long-term deficit rate is the follow-up result for the 672-case awake series.
Subsequent treatment is set through weekly multidisciplinary case discussion and monthly pathology review of selected cases, integrating molecular tumor diagnosis, post-operative care and prognostic information into an individualised plan.
Beyond surgery, the blood-brain barrier limits how much of some drugs reach the brain. The team has developed focused ultrasound combined with surgical navigation, using ultrasound and microbubbles to open the barrier temporarily in a target area, and is studying whether that improves drug delivery.
The system uses pre-treatment MRI for navigation, so magnetic resonance monitoring is not required throughout the procedure. The combination drug study uses acoustic feedback control to monitor the opening of the barrier.
The team first completed early clinical safety validation, then moved on to focused ultrasound combined with bevacizumab, and continues to take part in multicentre trials. The application remains at the clinical research stage, and efficacy has to be established through those trials.
The team also supports preclinical validation of NBM drug candidates and their progression into clinical trials. Its work includes advancing a locally developed ADI therapy through a multinational phase II trial in collaboration with leading medical centres in South Korea.
