School of Physics and Astronomy, University of Nottingham, Nottingham, UK.
Nottingham NHS Treatment Centre, Nottingham University Hospitals, Nottingham, UK.
Br J Dermatol. 2024 Aug 14;191(3):428-436. doi: 10.1093/bjd/ljae196.
Autofluorescence (AF)-Raman microspectroscopy is a technology that can detect residual basal cell carcinoma (BCC) on the resection margin of fresh, surgically excised tissue specimens. The technology does not require tissue fixation, staining, labelling or sectioning, and provides quantitative diagnosis maps of the surgical margins in 30 min.
To determine the accuracy of the AF-Raman instrument in detecting incomplete BCC excisions during Mohs micrographic surgery (MMS), using histology as the reference standard.
Skin layers from 130 patients undergoing MMS at the Nottingham University Hospitals NHS Trust (September 2022-July 2023) were investigated with the AF-Raman instrument. The layers were measured when fresh, immediately after excision. The AF-Raman results and the intraoperative assessment by Mohs surgeons were compared with a postoperative consensus-derived reference produced by three dermatopathologists. The sensitivity, specificity, and positive and negative predictive values were calculated. The study was registered with ClinicalTrials.gov (NCT03482622).
AF-Raman analysis was successfully completed for 125 of 130 layers and, on average, covered 91% of the specimen surface area, with the lowest surface area covered being 87% for the eyelid and the highest being 94% for forehead specimens. The AF-Raman instrument identified positive margins in 24 of 36 BCC-positive cases [67% sensitivity, 95% confidence interval (CI) 49-82] and negative margins in 65 of 89 BCC-negative cases (73% specificity, 95% CI 63-82). Only one of 12 false-negative cases was caused by misclassification by the AF-Raman algorithm. The other 11 false-negatives cases were a result of no valid Raman signal being recorded at the location of the residual BCC due to either occlusion by blood or poor contact between tissue and the cassette window. The intraoperative diagnosis by Mohs surgeons identified positive margins in 31 of 36 BCC-positive cases (86% sensitivity, 95% CI 70-95) and negative margins in 79 of 89 BCC-negative cases (89% specificity, 95% CI 81-95).
The AF-Raman instrument has the potential to provide intraoperative microscopic assessment of surgical margins in BCC surgery. Further improvements are required for tissue processing, to ensure complete coverage of the surgical specimens.
自发荧光（AF）-拉曼显微光谱技术是一种能够检测新鲜手术切除组织标本切缘残留基底细胞癌（BCC）的技术。该技术无需组织固定、染色、标记或切片，可在 30 分钟内提供手术切缘的定量诊断图。
使用组织学作为参考标准，确定 AF-拉曼仪器在检测莫氏显微外科手术（MMS）中不完全 BCC 切除时的准确性。
对诺丁汉大学医院 NHS 信托基金（2022 年 9 月至 2023 年 7 月）进行 MMS 的 130 名患者的皮肤层进行研究，使用 AF-拉曼仪器进行检测。当皮肤层处于新鲜状态时，在切除后立即进行测量。将 AF-拉曼结果和莫氏外科医生的术中评估与由三位皮肤科病理学家得出的术后共识参考结果进行比较。计算了敏感性、特异性、阳性和阴性预测值。该研究在 ClinicalTrials.gov 注册（NCT03482622）。
130 个皮肤层中有 125 个成功完成了 AF-Raman 分析，平均覆盖了标本表面面积的 91%，最低的覆盖面积为 87%，位于眼睑，最高的为 94%，位于额部标本。AF-Raman 仪器在 36 例 BCC 阳性病例中有 24 例（67%的敏感性，95%置信区间 49-82）识别出阳性切缘，在 89 例 BCC 阴性病例中有 65 例（73%的特异性，95%置信区间 63-82）识别出阴性切缘。只有 1 例假阴性是由于 AF-Raman 算法的错误分类造成的。其他 11 例假阴性是由于血液阻塞或组织与盒式窗之间接触不良，导致在残留 BCC 的位置没有记录到有效的拉曼信号。莫氏外科医生的术中诊断在 36 例 BCC 阳性病例中有 31 例（86%的敏感性，95%置信区间 70-95）识别出阳性切缘，在 89 例 BCC 阴性病例中有 79 例（89%的特异性，95%置信区间 81-95）识别出阴性切缘。
AF-拉曼仪器有可能提供 BCC 手术中手术切缘的术中显微镜评估。需要进一步改进组织处理，以确保手术标本的完全覆盖。
