Elena V. Zagaynova

Background. Breast cancer (BC) has been ranked first in morbidity and mortality among the female population in Russian Federation for several years. Rapid and accurate intraoperative examination of the cleanliness of resection margins is the main condition for breast-conserving surgery (BCS) to reduce the risks of local recurrence.Aim. To examine the tumor margins and assess the cleanliness of the resection margins in BCS in patients diagnosed with BC using multimodal optical coherence tomography (MM OCT) with comparative planned histological and additional molecular genetic analysis.Materials and methods. The study was carried out on postoperative samples of tumor and non-tumor breast tissue obtained from 115 patients with BC T1–2N0M0G2–3 stage IA–IIA, after BCS in the volume of radical resection or lumpectomy with histological control of the resection margins. A spectral domain MM OCT device (OCT 1300-E, BioMedTech LLC, Russia) was used, which provides structural OCT images to study the backscattering properties of tissue and allows performing a quantitative assessment of the elastic properties of the tissue by compression optical coherence elastography (OCE).Results. The MM OCT method was able to determine the exact margins between the tumor and non-tumor breast tissue. The main signs of the tumor were a decrease in the level and depth of penetration of the OCT signal in the structural OCT images, as well as an increase in the stiffness values (200 kPa) in the OCE images with the highest stiffness values (600 kPa) in the area of tumor cell accumulations. The use of compression OCE made it possible to detect clusters of tumor cells in the margins of resection at a distance of 5 mm from the visible border of the tumor. Among the 132 studied resection margins in 6 cases, the positive resection margin was determined by the OCE method, which was subsequently confirmed histologically. The negative resection margins were characterized by the lowest stiffness values (200 kPa) in the OCE images and were confirmed by both histological analysis and molecular genetic analysis. ROC-analysis established a threshold stiffness value of 159.8 kPa, which indicates the presence of tumor tissue at the resection margins in the presence of a high stiffness area larger than 500 µm. The high diagnostic accuracy of the OCE method (98.5 %) was determined to distinguish between the negative and positive resection margins during BCS.Conclusion. The use of MM OCT with OCE modality makes it possible to clearly distinguish different types of breast tissue in BC (adipose tissue, connective tissue, accumulation of tumor cells). MM OCT can be used as an additional intraoperative tool for visualizing tumor cells boundaries and assessing the cleanliness of resection margins in real time during BCS.

We demonstrate possibilities of multimodal OCT for quick distinguishing of uninformative necrotic zones from other morphological structures in freshly-excised breast cancer samples to improve information value of subsequent histological examination.

SPIE Digital Library Proceedings

SPIE Digital Library Proceedings

SPIE Digital Library Proceedings

Great number of factors, which influence the cell behavior and tissue formation at the injury site when using scaffolds are known. Here, we analyzed the effect of structural heterogeneity of scaffolds on cellular behavior. All scaffolds were obtained by two-photon polymerization technic. We found that the MSC behavior and metabolism have a great differences between the heterogeneous and standard tissue constructs. The main differences relate to cell migration, proliferation, and metabolic pathways. The heterogeneous scaffolds can significantly expand the fundamental knowledge of cellular behavior and the formation of various types of tissues in vitro and in vivo.

We present an optical coherence tomography (OCT) lymphangiography visualization approach based on analysis of speckle statistics. For in-vivo experimentation, normal and tumor tissues are examined in mouse dorsal skin window chamber model. In order to evaluate the speckle statistics, OCT datasets are acquired in 3 spatial and 1 temporal dimensions to be divided then into smaller volumes of interests. In temporal dimension, repeated same-location scanning is performed for simultaneous blood vessel detection through speckle variance processing. Speckle statistics in each volume of interest are tested for similarity to known distributions corresponding either to noise or to tissue. We show that lymphatic vessels could be detected using a specific parameter range of speckle statistics as a filter, to separate the surrounding tissues and blood vessels. The proposed approach does not require numerous post-processing steps that are often used in lymphatic detection methods that are based on low signal amplitude regions (e.g., OCT signal attenuation compensation, inversion, amplitude thresholding etc.). Instead, we use a fast 2-step filtering procedure to reveal lymphatic vessels in imaged tissues.

Cysteine proteases, caspases, play an important role in the process of programmed cell death. In apoptosis, the cell signaling pathways overlap at executioner caspases regardless of the initial...