Confocal Ex Vivo Margin Assessment in Transoral Laser Cordectomy: A Pilot Diagnostic Accuracy Study

Margin assessment in transoral laser microsurgery (TLM) for glottic squamous cell carcinoma is challenging due to specimen size, fragmentation, and artifacts. This study evaluated the feasibility and preliminary diagnostic performance of the Histolog Scanner, an ultra-fast ex vivo confocal microscopy system, for intraoperative margin assessment in TLM cordectomy.

This prospective pilot study evaluated adult patients undergoing TLM cordectomy for glottic squamous cell carcinoma. Five predefined margins per specimen (anterior, posterior, superior, inferior, deep) were evaluated using Histolog Scanner and compared with conventional hematoxylin and eosin histopathology, used as the reference standard. Concordance, sensitivity, specificity, predictive values, and diagnostic accuracy were assessed.

Nineteen patients were included, yielding to 95 evaluable margins. Overall concordance between Histolog Scanner and histopathology was 92.6% (88/95 margins). The scanner identified 12 true-positive, 76 true-negative, five false-positive, and two false-negative margins. Sensitivity was 85.7% (95% CI: 57.2-98.2), specificity 93.8% (95% CI: 86.2-98.0), positive predictive value 70.6% (95% CI: 44.0-89.7), negative predictive value 97.4% (95% CI: 91.0-99.7), and accuracy 92.6% (95% CI: 85.4-97.0). Agreement was substantial (Cohen's kappa = 0.73). Mean acquisition time was 13 min per specimen.

The Histolog Scanner is a feasible, rapid intraoperative screening tool with high specificity and excellent negative predictive value for ruling out involved margins in TLM cordectomy. It serves as an intraoperative adjunct rather than a replacement for definitive histopathology, which remains essential. Larger multicenter studies are required before widespread clinical setting implementation.