Department of Dermatology, Université Libre de Bruxelles, Hôpital Erasme, Brussels, Belgium.
Department of Dermatology, University of Barcelona, Barcelona, Spain.
J Eur Acad Dermatol Venereol. 2015 Aug;29(8):1606-15. doi: 10.1111/jdv.12954. Epub 2015 Feb 5.
Preliminary studies described morphological features of actinic keratosis (AK) and squamous cell carcinoma (SCC) imaged by High-Definition Optical Coherence Tomography (HD-OCT) and suggested that this technique may aid in their diagnosis. However, systematic studies evaluating the accuracy of HD-OCT for the diagnosis of AK and SCC are lacking so far.
In this study, we sought to design an algorithm for AK classification that could (i) distinguish SCC from AK and normal skin, (ii) differentiate AK from normal skin and (iii) discriminate AKs with adnexal involvement from those without.
A total of 53 histopathologically confirmed lesions (37 AKs and 16 SCC) were imaged by HD-OCT. Fifty-three HD-OCT images of normal skin of healthy volunteers, with matched age, skin type and anatomic site, were taken as reference. By comparing these 106 en face and cross-sectional HD-OCT images, particular features were selected based on their potential to discriminate AK from normal skin and from SCC, and to assess adnexal involvement in AK. This study represents a training set not a testing set. Severe (>300 μm) hyperkeratotic AKs were not included in this study.
Particular features with high Phi coefficient could be identified. The absence of an outlined dermo-epidermal junction (DEJ) on cross-sectional images allowed discriminating SCC from AK and normal skin (Phi coefficient = 0.84). AK could be discriminated from normal skin in both imaging modes by the presence of alternating hyperkeratosis/parakeratosis in cross-sectional mode and/or variability in shape, size and reflectivity of cells (atypical honeycomb pattern) in en face mode. Adnexal involvement of AK could be assessed by the disappearance of the typical cocarde image of adnexal epithelium in en face mode.
This study provides select 3-D HD-OCT features having a potential to discriminate SCC from AK and normal skin. Based on these particular features with high Phi coefficient, a diagnostic algorithm is designed which will be used later in validation studies to determine HD-OCT accuracy in AK/SCC classification.
初步研究描述了光相干断层扫描（HD-OCT）成像下光化性角化病（AK）和鳞状细胞癌（SCC）的形态特征，并表明该技术可能有助于其诊断。然而，迄今为止，尚无系统研究评估 HD-OCT 对 AK 和 SCC 诊断的准确性。
本研究旨在设计一种 AK 分类算法，该算法能够（i）将 SCC 与 AK 和正常皮肤区分开来，（ii）将 AK 与正常皮肤区分开来，（iii）区分有附属物受累的 AK 与无附属物受累的 AK。
对 53 例经组织病理学证实的病变（37 例 AK 和 16 例 SCC）进行了 HD-OCT 成像。对 53 例来自健康志愿者的正常皮肤的 HD-OCT 图像进行了拍摄，这些图像的年龄、皮肤类型和解剖部位相匹配，作为参考。通过比较这 106 张共面和横截面 HD-OCT 图像，根据它们区分 AK 与正常皮肤和 SCC 的潜力，以及评估 AK 中附属物受累的能力，选择了特定的特征。本研究代表了一个训练集，而不是一个测试集。本研究未包括严重（>300μm）角化过度的 AK。
可以识别出具有高 Phi 系数的特定特征。横截面图像中无明确的表皮-真皮交界（DEJ）可区分 SCC 与 AK 和正常皮肤（Phi 系数=0.84）。在两种成像模式下，AK 均可以通过横截面模式中交替出现的过度角化/不全角化和/或细胞形状、大小和反射率的变化（非典型蜂窝状模式）与正常皮肤区分开来。共面模式下附属物上皮典型的 cocarde 图像消失可评估 AK 中附属物的受累情况。
本研究提供了一些具有区分 SCC 与 AK 和正常皮肤潜力的特定 3D-HD-OCT 特征。基于这些具有高 Phi 系数的特定特征，设计了一种诊断算法，该算法将在后续的验证研究中用于确定 HD-OCT 在 AK/SCC 分类中的准确性。
