gms | German Medical Science

Objective: Intraoperative imaging of vital neural structures on a cellular level during neurosurgery would facilitate the development of new strategies for diagnosis and treatment and offer new views for research. In vivo imaging allows detecting the tumour centre and the infiltration zone. With targeted biopsies, the lesion of interest is determined before biopsy is performed. This would facilitate and ensure the final pathological diagnosis. In this study, we introduce confocal neurolasermicroscopy as a new method applied in neurosurgery.

Methods: Confocal neurolasermicroscope as a miniaturized device (NLM) was introduced ex vivo immediately after tumour resection of glioblastoma multiforme (GBM). NLM was performed with a 1000x magnification up to a tissue depth of 100μm. NLM images were compared to conventional histology of the same tumour.

Results: The NLM images of nine patients with histologically proven GBM were analysed for the presence of WHO criteria of GBM. In all 9 patients, cell density and cell pleomorphy were clearly visible with NLM. Further WHO criteria for tumour classification to identify GBM were compared to histology and were identified in some but not all patients. In 44% of the patients (4/9), microvascular proliferation was visible and in 22% of the patients (2/9) mitosis and necrosis was identified. Further phenomena such as pleomorphic cells, mitotic figures, fibrillary matrix and the distinction of tumour centre and the infiltration zone were characterized.

Conclusions: NLM is a tool which could be adapted to neurosurgical intraoperative application with the potential of diagnosing the tumour centre and recognition of the tumour infiltration zone in vivo. Neurolasermicroscopy is an easy to handle tool. In all nine patients with GBM, typical characteristics of tumour architecture were depicted. Identification of the infiltration zone or the centre of the tumour is possible in any patient by a etermination of the cell density.