Ultraviolet-Visible Spectrophotometric Analysis of Intracranial Cyst Fluid: A Technical Note.

Abstract

Intraoperative cyst fluid is readily available during the surgical treatment of cystic intracranial lesions but is rarely subjected to systematic optical analysis. We describe a practical workflow for ultraviolet-visible (UV-Vis) spectrophotometric evaluation of intracranial cyst fluid and report our initial technical experience. Cyst fluid samples obtained intraoperatively from 16 patients with cystic intracranial lesions were processed by centrifugation and analyzed using UV-Vis spectrophotometry across a wavelength range of 250-720 nm. Following preliminary assessment of undiluted specimens, a standardized 1:10 dilution protocol was implemented to avoid detector saturation and ensure reproducible spectral acquisition. Spectral profiles were evaluated descriptively and explored using principal component analysis. Standardized processing and UV-Vis acquisition were feasible in all samples. Undiluted specimens frequently exceeded the linear detection range of the spectrophotometer, whereas diluted samples yielded stable and reproducible absorbance spectra. Heterogeneous spectral profiles were observed across specimens, demonstrating the ability of the workflow to capture optical variability within cyst fluid samples. UV-Vis spectrophotometric analysis of intracranial cyst fluid can be performed using a simple and reproducible workflow based on routine laboratory equipment. This technical experience provides a framework for future investigations of the optical characteristics of cystic intracranial lesions.