Introduction: Intraoperative imaging was introduced also to update neuronavigation data, to try and solve the brain-shift phenomenon-related pitfalls and increase overall safety. Nevertheless, each intraoperative imaging modality has some intrinsic limitations and technical shortcomings, making its clinical use challenging.
We used a multimodal intraoperative imaging protocol to update neuronavigation, based on the combination of intraoperative Ultrasound (i-US) and intraoperative Computed Tomography (i-CT) integrated with 5-ALA fluorescence and neuromonitoring-guided resection.
Methods: This is a pilot study on 52 patients (29 men), including four children, with a mean age of 57.67 years, suffering from brain low- (10 patients) or high-grade (34 patients) glioma or metastasis (8 patients), prospectively and consecutively enrolled. They underwent 5-ALA fluorescence-guided microsurgical tumor resection and neuromonitoring was used in cases of lesions located in eloquent areas, according to pre-operative clinical and neuroradiological features. A protocol combining the intraoperative use of i-CT and I-US was applied to the cohort.Clinical evaluation was based on comparison of pre- and post-operative Karnofsky Performance Score (KPS) and assessment of Overall Survival (OS) and Progression Free Survival (PFS). Extent of tumor resection (EOTR) was evaluated by volumetric post-operative Magnetic Resonance performed within 48 h after surgery.
Results: 5-ALA was strongly or vaguely positive in 45 cases (86.5%). Seven lesions (4 low-grade glioma, 1 high-grade glioma and 2 metastases) were not fluorescent. i-US visualized residual tumor after resection of all fluorescent or pathological tissue in 22 cases (42.3%). After i-US guided resection, i-CT documented the presence of further residual tumor in 11 cases (21.1%).
Mean EOTR was 98.79% in the low-grade gliomas group, 99.84% in the high-grade gliomas group and 100% in the metastases group.
KPS changed from 77.88, pre-operatively, to 72.5, post-operatively. At the last follow-up, mean KPS was 84.23.
Conclusions: The combination of different intraoperative imaging modalities may increase safety and extent of resection of intra-axial brain tumors.
Patient Care: A rationalized use of different imaging modalities may improve the patients' outcome in terms of neurological aoutcome and survival.
Learning Objectives: 1. To understand the importance of combining different intraoperative modalities to increase the EOR of brain tumors
2. To investigate the role of neuromonitoring in combination with imaging guided surgery, to improve the safety of resection
3. To discuss the moder multimodal approach to technology applied to classical microsurgery.