Tumor Models for Training of Fluorescence-Guided Brain Tumor Resection

BACKGROUND AND OBJECTIVES: Neurosurgical resection of brain tumors is a technically demanding task with a steep initial learning curve. Experience has been shown to improve surgical performance and increase the rates of resection. High-grade gliomas (HGG) are responsible for 65% of all primary malignant central nervous system tumors and are the commonest surgically treated brain tumor worldwide. There is increasing evidence that maximal safe surgical resection of HGG impacts on overall survival. The delineation of tumor tissue (and hence the extent of resection) is improved by the use of intraoperative tumor fluorescence, which is achieved by preoperative oral administration of 5-aminolevulinic acid. This however relies on the surgeon developing a skillset of operating under different light conditions for which specific training and experience are required. METHODS: We propose a novel, affordable, and highly adaptable model for recreating these surgical conditions and thus simulate fluorescence-guided HGG resection outside the operating theater for trainee neuro-oncological surgeons. We present a model incorporating plant-based polysaccharides, doped with protoporphyrin IX (PpIX), into cadaveric brains of animals. RESULTS: We show that the concentrations of polymer and PpIX can be titrated (using previously published data) to produce mechanical and fluorescence properties that model tumor tissue. We validate the simulation in a neurosurgical skills laboratory. Furthermore, we used a mini spectrometer with handheld probe to collect fluorescence signals and validate the spectroscopic signal from the PpIX. CONCLUSION: It is hoped that this model system will be useful in neurosurgical teaching and training courses and to neurosurgeons who want to try out new techniques or equipment in anatomy laboratories.