Molly Sebastian, MD, FACS & Stephanie Akbari, MD, FACS; Reinsch Pierce Family Center for Breast Health, Virginia Hospital Center, Arlington, VA. Beth Anglin MD, FACS; Complete Breast Care, The Medical Center of Plano, Plano, TX. Erin H Lin DO & Alice M Police MD, FACS; Department of Surgical Oncology, University of California Irvine, CA.
Obtaining clear margins following a partial mastectomy (also known as a lumpectomy) surgery for breast cancer is an important factor in the treatment of breast cancer while conserving the breast (BCS). Positive margins result in reexcision procedures performed in order to achieve clear margins. We present the cumulative experience of routine use of MarginProbe, a tool for intra-operative margin assessment in partial mastectomy procedures, by four breast surgeons in three centers. This is a retrospective, observational chart review from sets of consecutive patients in each of these breast centers – before and after the device was put into use during partial mastectomy procedures. The effect use of the device had on the rate of re-excision procedures is reported.
Materials and Methods
Patients were pre-diagnosed with cancer, histologically confirmed by biopsy. Lesions were localized and excised by standard methods. The intraoperative margin assessment device was used on all circumferential margins of the main specimen, but not on any additional shavings. A positive reading by the device led to an additional shaving of the corresponding cavity location. Specimens were also, when feasible, imaged intra-operatively by X-ray, with additional shavings taken if needed based on clinical assessment. For each surgeon, historical data were obtained for a time period of approximately one year, proximal to the initiation of use of the device.
From Mar 2013 to Oct 2014 the device was routinely used in a series of consecutive BCS cases, by 4 surgeons in 3 centers. Subjects’ baseline characteristics are presented in Table 1.
Re-excision procedures are presented in Table 2. With use of the device, positive margins resulted in additional re-excision procedures in 10.7% (31/290) of the cases. The historical set consisted of 186 Lumpectomy cases, in which there were additional re-excision procedures performed in 25.8% (48/186) of the cases. The reduction in the rate of re-excision procedures was significant – 59% (P<0.0001). The relative reduction was similar across surgeons, irrespective of the per surgeon nominal rates of re-excision procedures.
Table 3 presents an analysis using the recently updated SSO guidelines of “no tumor on ink” the recommended standard for a clear margin. There were 19% (56/290) of the primary (main) lumpectomy specimen, prior to intra-operative assessment, which had positive margins. Use of the device lead to identification of the positive margins in the operating room in 75% (42/56) of these cases. There was a 6.6% (19/290) rate of re-excision procedures due to tumor on ink in the final pathologic analysis. Only 3.4% (10/290) of the re-excision procedures were due to failed detection of positive margins on the main specimen, where the device was used.
It is notable that this study points to an even stronger potential for re-excision reduction, as using “no ink on tumor” only 10 patients, representing 3.4%, had re-excision procedures due to main specimen positive margins, where the device was applied. This figure raises the possibility that in the era of the new guidelines for re-excision, low single digit re-excision rates are within reach, if combined with intraoperative margin assessment. It would therefore be important to investigate how to best incorporate device use on the shavings.
About Dune Medical Devices
Dune Medical Devices was founded in 2002 by Dr. Dan Hashimshony, CEO, to realize the extraordinary medical potential of its proprietary tissue characterization technology. Offering surgeons and radiologists the real-time ability to identify cancerous tissues and react immediately, this technology holds the potential for a broad range of surgical and diagnostic applications. Dune Medical Devices is a privately held company with offices in the U.S. and Israel. For more information, please visit www.dunemedical.com and www.marginprobe.com.
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