A newly developed optical touch pointer can be used to differentiate healthy tissues from tumours and help surgeons during the resection of malignant brain tumours, a study published in the journal Lasers in Surgeryhas reported. The optical touch pointer, which uses fibre-optic fluorescence spectroscopy, generates fluorescence ratios to indicate healthy tissue and tumours. For the study, researchers from Linkoping University in Sweden evaluated the optical touch pointer in nine patients undergoing standard resection for possible glioblastoma multiforme tumours, through white light microscopy and ultrasound-based navigation. The results showed that the optical touch pointer successfully identified and differentiated healthy tissue from tumour tissue. The fluorescence ratios obtained from the optical touch pointer showed that the ratio outside the tumour was zero, was low in the gliotic oedema zone, high in the marginal zone, highest in the solid tumour tissue, and zero in the necrotic tissue in the tumour’s centre. Researchers note that the optical touch pointer can be used in combination with ultrasound-based navigation to determine whether to resect otherwise non-identifiable tissue.