The combination of a high-resolution, 3-dimensional imaging technique in combination with a quantitative measurement of tissue elasticity could help surgeons accurately detect cancer within the resected margins of surgical specimens taken from patients undergoing breast-conserving surgery, according to the results of a recent study.
“Despite living in the ‘digital age,’ surgeons must routinely rely on their eyesight and sense of touch to determine if they have removed the entire tumor during breast-conserving surgery,” Brendan F. Kennedy, PhD, associate professor in the school of engineering at The University of Western Australia (UWA) and laboratory head of BRITElab at the Harry Perkins Institute of Medical Research in Perth, Western Australia, said in a press release.
Current methods used to examine margins of surgical specimens are lacking, and inadequate margins in breast-conserving surgery are associated with an increased likelihood of local recurrence of breast cancer.
In this study, researchers tested quantitative microelastography (QME) and optical coherence tomography (OCT) to produce images of tissue microscale elasticity for detecting tumor within 1 mm of the margins of breast conserving surgery specimens. The study included 83 patients undergoing breast-conserving surgery and 7 patients undergoing mastectomy.
For the pilot data set, all mastectomy surgical samples and surgical samples from 12 patients who underwent breast-conserving surgery were used to train 7 readers to determine if images generated by the QME and the OCT indicated the presence of cancer in the surgical margins.
Surgical samples from the remaining 71 patients who received breast-conserving surgery were used to determine the ability of OCT and QME to detect cancer within 1 mm of the surgical margins, as compared with gold-standard postoperative histology. Readers were blinded to the histopathology results.
The study showed that OCT images had a 69% sensitivity, 79% specificity, and 77.5% accuracy for detecting cancer within 1 mm or surgical margin. QME had a 92.9% sensitivity, 96.4% specificity, and 95.8% accuracy.
“Imaging the microscale stiffness of tissue using QME has the potential to reduce re-excision rates in breast-conserving surgery,” Dr Kennedy said in the press release. “Further, by quantifying tissue stiffness, we remove the subjectivity that is inherent to the surgeon’s sense of touch. The ideal scenario would be to perform the imaging in the surgical cavity immediately after the specimen has been removed.”
Kennedy KM, Zilkens R, Allen WM, et al. Diagnostic accuracy of quantitative micro-elastography for margin assessment in breast-conserving surgery. 2020;80(8):1773-1783.