Department of Surgery, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Postbus 90203, 1006, Amsterdam, BE, Netherlands.
Department of Pathology, Ghent University Hospital, and Cancer Research Institute Ghent (CRIG), Ghent University, Ghent, Belgium.
Breast Cancer Res. 2021 May 22;23(1):59. doi: 10.1186/s13058-021-01436-5.
Although the incidence of positive resection margins in breast-conserving surgery has decreased, both incomplete resection and unnecessary large resections still occur. This is especially the case in the surgical treatment of ductal carcinoma in situ (DCIS). Diffuse reflectance spectroscopy (DRS), an optical technology based on light tissue interactions, can potentially characterize tissue during surgery thereby guiding the surgeon intraoperatively. DRS has shown to be able to discriminate pure healthy breast tissue from pure invasive carcinoma (IC) but limited research has been done on (1) the actual optical characteristics of DCIS and (2) the ability of DRS to characterize measurements that are a mixture of tissue types.
In this study, DRS spectra were acquired from 107 breast specimens from 107 patients with proven IC and/or DCIS (1488 measurement locations). With a generalized estimating equation model, the differences between the DRS spectra of locations with DCIS and IC and only healthy tissue were compared to see if there were significant differences between these spectra. Subsequently, different classification models were developed to be able to predict if the DRS spectrum of a measurement location represented a measurement location with "healthy" or "malignant" tissue. In the development and testing of the models, different definitions for "healthy" and "malignant" were used. This allowed varying the level of homogeneity in the train and test data.
It was found that the optical characteristics of IC and DCIS were similar. Regarding the classification of tissue with a mixture of tissue types, it was found that using mixed measurement locations in the development of the classification models did not tremendously improve the accuracy of the classification of other measurement locations with a mixture of tissue types. The evaluated classification models were able to classify measurement locations with > 5% malignant cells with a Matthews correlation coefficient of 0.41 or 0.40. Some models showed better sensitivity whereas others had better specificity.
The results suggest that DRS has the potential to detect malignant tissue, including DCIS, in healthy breast tissue and could thus be helpful for surgical guidance.
尽管保乳手术中的阳性切缘发生率有所下降，但仍存在不完全切除和不必要的大范围切除的情况。这在导管原位癌（DCIS）的手术治疗中尤为明显。基于光与组织相互作用的漫反射光谱（DRS）技术，在手术过程中有可能对组织进行特征描述，从而为外科医生提供术中指导。DRS 已被证明能够区分纯健康的乳腺组织和纯浸润性癌（IC），但对（1）DCIS 的实际光学特性和（2）DRS 对组织类型混合物进行特征描述的能力的研究有限。
本研究共采集了 107 例经证实患有 IC 和/或 DCIS（1488 个测量部位）的 107 例患者的 107 个乳腺标本的 DRS 光谱。通过广义估计方程模型，比较了 DCIS 与 IC 和仅健康组织的部位的 DRS 光谱之间的差异，以确定这些光谱之间是否存在显著差异。随后，开发了不同的分类模型，以能够预测测量部位的 DRS 光谱是否代表“健康”或“恶性”组织。在模型的开发和测试中，对“健康”和“恶性”采用了不同的定义。这使得训练和测试数据的同质性水平可以发生变化。
发现 IC 和 DCIS 的光学特性相似。关于组织类型混合物的分类，发现在开发分类模型时使用混合测量部位并不会极大地提高对组织类型混合物的其他测量部位的分类准确性。评估的分类模型能够以 0.41 或 0.40 的马修斯相关系数对>5%恶性细胞的测量部位进行分类。一些模型具有更好的敏感性，而其他模型具有更好的特异性。
结果表明，DRS 有可能在健康的乳腺组织中检测到包括 DCIS 在内的恶性组织，因此可能有助于手术指导。
