Magnetic resonance imaging system for intraoperative margin assessment for DCIS and invasive breast cancer using the ClearSight™ system in breast-conserving surgery-Results from a postmarketing study.

BACKGROUND AND OBJECTIVES: Breast-conserving surgery (BCS) is followed by reoperations in approximately 25%. Reoperations lead to an increased risk of infection and wound healing problems as well as a worse cosmetic outcome. Several technical approaches for an intraoperative margin assessment to decrease the reoperation rate are under evaluation, some of them are still experimental. METHODS: A prospective single-arm post-marketing study with 60 patients undergoing BCS for ductal carcinoma in situ (DCIS) and invasive breast cancer was conducted. The specimen was intraoperatively examined by the ClearSight™ system, a mobile magnetic resonance imaging system that is based on a diffusion-weighted imaging protocol. However, the results were blinded to the surgeon. RESULTS: The ClearSight™ system was performed for both ductal and lobular breast cancer and DCIS, with a sensitivity of 0.80 (95% confidence interval [CI]: 0.44-0.96) and a specificity of 0.84 (95% CI 0.72-0.92), with an overall diagnostic accuracy of 80%. CONCLUSION: Had the ClearSight™ been known to the surgeon intraoperatively, the reoperation rate would have been reduced by 83% for invasive carcinoma, from 10% to 2%, and 50% for DCIS, from 30% to 15% reoperations. A trial designed to examine the impact on reoperation rates is currently ongoing.

An intraoperative MRI system for margin assessment in breast conserving surgery: Initial results from a novel technique.

BACKGROUND AND OBJECTIVES: One of the major unmet needs in Breast Conserving Surgery (BCS) is a rapid and accurate margin assessment of the lumpectomy specimen. This study evaluates the ability of a novel MRI system (prototype of the ClearSight™ system; Clear-Cut Medical Ltd., Rehovot, Israel) to distinguish malignant and non-malignant tissues in freshly excised breast specimen by comparing MR measurements to histopathology results. METHODS: Seventy-seven samples were obtained from 22 patients undergoing BCS enrolled in the study. A T2* (T2 Star) value in milliseconds (ms) was calculated for each sample and correlated with histopathology results. RESULTS: Of the 77 samples, 35 samples were classified by histopathology as malignant and 42 as non-malignant. T2* values were significantly higher in malignant samples compared to non-malignant samples (15.3 ± 2.72 ms and 10.6 ± 1.47 ms, respectively [P < 0.00001]). Analysis for a determined cutoff of 11.7 ms revealed 91% sensitivity, 93% specificity, and 92% accuracy. ROC curve analysis yielded AUC of 0.97. CONCLUSIONS: This study demonstrates that the system is sensitive and specific in differentiating malignant and non-malignant tissues in freshly excised breast specimen. The system has the potential to be used for breast specimen margin assessment during BCS, with the goal of decreasing the need for re-operation. J. Surg. Oncol. 2016;114:22-26. © 2016 Wiley Periodicals, Inc.