Intraoperative Assessment of Final Margins with a Handheld Optical Imaging Probe During Breast-Conserving Surgery May Reduce the Reoperation Rate: Results of a Multicenter Study

Abstract

Background A multicenter, prospective, blinded study was performed to test the feasibility of using a handheld optical imaging probe for the intraoperative assessment of final surgical margins during breast-conserving surgery (BCS) and to determine the potential impact on patient outcomes. Methods Forty-six patients with early-stage breast cancer (one with bilateral disease) undergoing BCS at two study sites, the Johns Hopkins Hospital and Anne Arundel Medical Center, were enrolled in this study. During BCS, cavity-shaved margins were obtained and the final margins were examined ex vivo in the operating room with a probe incorporating optical coherence tomography (OCT) hardware and interferometric synthetic aperture microscopy (ISAM) image processing. Images were interpreted after BCS by three physicians blinded to final pathology-reported margin status. Individual and combined interpretations were assessed. Results were compared to conventional postoperative histopathology. Results A total of 2,191 images were collected and interpreted from 229 shave margin specimens. Of the eight patients (17 %) with positive margins (0 mm), which included invasive and in situ diseases, the device identified all positive margins in five (63 %) of them; reoperation could potentially have been avoided in these patients. Among patients with pathologically negative margins (>0 mm), an estimated mean additional tissue volume of 10.7 ml (approximately 1 % of overall breast volume) would have been unnecessarily removed due to false positives. Conclusions Intraoperative optical imaging of specimen margins with a handheld probe potentially eliminates the majority of reoperations.

Review of intraoperative optical coherence tomography: technology and applications [Invited]

“…14). A similar study, conducted with a commercial HHOCT device, suggested that intraoperative margin analysis in shave margin specimens could reduce reoperation rates at the cost of small increases in resected tissue volume [95]. The Boppart group has also advanced OCT for non-destructive detection of breast cancer metastasis in lymph nodes [196,197].…”

“…The intraoperative HHOCT probe's size was significantly decreased by using the MEMS scanner, and the probe's functionality was tested during anastomosis performed in vivo in a mouse surgical model [91]. Moreover, a contact-based intrasurgical HHOCT probe for tumor margin analysis during human breast surgery was demonstrated in 2015 [94], and a similar probe has since been commercialized by Diagnostic Photonics, Inc [95]. The commercial probe was coupled to a 1300 nm swept-source OCT system and used a MEMS scanner to acquire images with a transverse resolution of ~15 µm over a 9 mm lateral field of view [95].…”

“…Moreover, a contact-based intrasurgical HHOCT probe for tumor margin analysis during human breast surgery was demonstrated in 2015 [94], and a similar probe has since been commercialized by Diagnostic Photonics, Inc [95]. The commercial probe was coupled to a 1300 nm swept-source OCT system and used a MEMS scanner to acquire images with a transverse resolution of ~15 µm over a 9 mm lateral field of view [95]. The longer operating wavelength resulted in poorer axial resolution compared to 850 nm HHOCT for retinal imaging but longer penetration depth, which was beneficial for imaging turbid media such as normal and pathologic breast tissue.…”

“…An intraoperative HHOCT probe for breast surgery incorporated interferometric synthetic aperture microscopy (ISAM) [162], a computational refocusing algorithm that could yield more uniform lateral resolution along the imaging depth. The resulting OCT images with improved lateral resolution were used to identify tumor margins during human breast surgery [95]. Additionally, variations in collagen orientation and content was also exploited to differentiate cancerous tissue from healthy ex vivo breast tissue using polarization-sensitive OCT [163].…”

Computational optical coherence tomography [Invited]

“…Another key clinical application is intraoperative imaging of cancer margins during breast conserving surgery. A recent clinical study demonstrated that a majority of reoperations could potentially be prevented through the use of intraoperative computational OCT imaging [87].…”