LAUSR

BACKGROUND Needle biopsy is a routinely, relatively safe, and effective tool for patients with brain tumours not suitable for surgical resection. Despite technical advancements, missed diagnosis is still reported in up to 24% of cases. The aim of this study is to investigate the role of sodium fluorescein (NaFL), a cheap and safe fluorophore, in the biopsy setting mainly with the perspective of an enhancement of the sampling accuracy. METHODS Between January 2018 and March 2020, we prospectively enrolled 48 consecutive patients with suspicion of high-grade glioma to receive NaFL-guided brain tumour biopsy. We compared results between NaFL-group and our historical cohort of patients that underwent biopsy without any dye administration (n=58). RESULTS In the NaFL-guided biopsy group, there was a statistically significant increase in diagnostic accuracy compared to the historical cohort (100% vs. 86.2% - p<.05). The mean number of samples was significantly reduced, (3.3 instead of 4.4 of the control group - p<.05). Differences in terms of complications related to the procedure, hospital stay, and surgical time were not significant (p=0.49). CONCLUSIONS To the authors' knowledge, this is the largest published series supporting the usefulness of NaFL during biopsy procedure, with improved diagnostic accuracy. This also allows a reduction in the number of samples needed for diagnosis, and subsequent risks of procedurerelated complications, without adding risks related to the drug itself.