The LaserSAFE technique for margin assessment during radical prostatectomy: a feasibility study

OBJECTIVES: To assess the feasibility of conducting a multicentre trial comparing NeuroSAFE with a novel technique based on confocal laser microscopy (LaserSAFE) and evaluate the diagnostic performance of LaserSAFE for real-time surgical margin assessment. PATIENTS AND METHODS: This was a non-randomised, prospective feasibility study conducted at a high-volume academic UK centre (ClinicalTrials.gov identifier: NCT06398470). Patients with localised prostate cancer (clinical T2-T3a N0 M0) scheduled for robot-assisted radical prostatectomy and deemed unsuitable for bilateral intrafascial nerve sparing (NS) based on a multidisciplinary plan were included. LaserSAFE imaging was performed in the operating room after which the NeuroSAFE technique results guided NS decisions. Pathologists, blinded to NeuroSAFE and final histology, retrospectively evaluated LaserSAFE images. Diagnostic accuracy metrics and concordance between modalities were calculated. Feasibility was assessed based on recruitment rate and the ability to activate additional sites. RESULTS: A total of 20 patients were recruited at a single site within 12 months of recruitment start. However, expansion to additional centres was not feasible due to limitations in implementing the NeuroSAFE protocol. LaserSAFE achieved a sensitivity of 0.91 (95% confidence interval [CI] 0.59-1.00) and specificity of 1.00 (95% CI 0.88-1.00) for detecting positive surgical margins ≥0.5 mm. Cohen's kappa demonstrated strong agreement with NeuroSAFE and final pathology. LaserSAFE was completed within a median of 7 min, significantly shorter than the 63 min required for NeuroSAFE. Limitations include the small sample size, single-centre setting, and lack of intraoperative decision-making based on LaserSAFE findings. CONCLUSION: While a multicentre study based on NeuroSAFE as a comparison was not achievable, LaserSAFE proved to be a rapid and accurate alternative for intraoperative margin assessment. These findings support the design of a larger trial in which NS decisions are informed by LaserSAFE, with a view to broadening access to real-time margin assessment.