Abstract 1131P
Background
Breast conserving surgery (BCS) has become increasingly accepted as the surgical management of breast cancer in clinical practice. The main goal of BCS is the complete removal of cancer with clear surgical margins. This study demonstrates the results of the diagnostic accuracy of compression optical coherence elastography (C-OCE) method in ex vivo determining of “positive” and “negative” surgery margins in BCS.
Methods
The studies were carried out by multimodal spectral optical coherence tomograph (IAP RAS, Russia) in elastographic mode. C-OCE can in real-time determine absolute stiffness values (Young's modulus, kPa) of the tissue with a resolution of 40-50 μm at a depth up to 2 mm. 25 female patients who underwent BCS for invasive ductal or lobular carcinomas were enrolled to the study. Four fresh tissue samples per patient were harvested <5 mm from the tumor (upper, lower, lateral, medial). Sensitivity, specificity and diagnostic accuracy were calculated by comparing the predicted margin status from the OCE imaging with the true margin status by histology. Based on the sensitivity and specificity values, the Receiver operating characteristic (ROC) curves and the area under ROC curve were calculated.
Results
Histological examination revealed 4 of 100 specimens with tumor cells (“positive” surgical margins) from in situ and invasive carcinoma. In 96 of 100 specimens adipose, adipose with streaks of connective tissue or fibrosis were found by histology (“negative” surgical margins). C-OCE method detected “positive” and “negative” surgical margins at the same specimens. The good agreement between C-OCE and histology was established. Young's modulus in the frame 500х500 μm on C-OCE images was chosen to characterize breast tissue elasticity properties. For detecting “positive” surgery margins, threshold equal to >159kPa was proposed. This threshold provides sensitivity = specificity = 94.4% (94.2% diagnostic accuracy). The area under the ROC curve was equal to 0.98.
Conclusions
Adjusted threshold for determining tumor areas on C-OCE images is characterized by high diagnostic efficiency and can be used to identify in real-time residual tumor cells at the surgical margins during breast conserving surgery.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Russian Science Foundation, grant 18-75-10068.
Disclosure
All authors have declared no conflicts of interest.