Use of a novel device to reduce positive margins for ductal carcinoma in situ.

87 Background: The ability to obtain negative margins with a single surgical procedure remains a challenge, particularly in patients with ductal carcinoma in situ (DCIS). A novel device (MarginProbe, Dune Medical Devices, Inc.) is intended to provide surgeons with real-time, intraoperative detection of cancerous tissues at the margins of excised specimens. A study was performed to determine if there was a device-associated improvement in complete surgical resection (CSR) and therefore a decreased re-excision rate in patients with a DCIS component. Methods: 596 patients who were undergoing breast conservation using needle localization were randomized in a prospective, international, multicenter (n=21) study. Randomization occurred in the operating room, following standard of care lumpectomy, including palpation followed by indicated additional cavity resections. Device positive readings required additional resections of the cavity. Pathologists were blinded to study arm. A primary endpoint of this study was CSR, defined as the correct intraoperative identification and resection (if not skin or fascia) of all positive margins on the main lumpectomy specimen. Positive lumpectomy specimens were those having at least one margin having cancer ≤1mm from the surface. Successful CSR results in reduced positive margin rate after lumpectomy. Results: The improvement in CSR was significant for each diagnosis (p<0.0001). The decrease in candidates for reexcision due to failed CSR was significant for all pathology involving DCIS (p<0.0001). Overall results are presented in the table. Conclusions: Device use delivered significant improvement in CSR and therefore a significant decrease in reexcision rates for patients with DCIS. Further studies need to be conducted evaluating the use of the device on additional margins that the surgeon may resect or in the actual cavity. [Table: see text]