Real-time Imaging of the Resection Bed Using a Handheld Probe to Reduce Incidence of Microscopic Positive Margins in Cancer Surgery

Abstract

Wide local excision (WLE) is a common surgical intervention for solid tumors such as those in melanoma, breast, pancreatic, and gastrointestinal cancer. However, adequate margin assessment during WLE remains a significant challenge, resulting in surgical re-interventions to achieve adequate local control. Currently no label-free imaging method is available for surgeons to examine the resection bed in vivo for microscopic residual cancer. Optical coherence tomography (OCT) enables real-time high-resolution imaging of tissue microstructure. Previous studies have demonstrated that OCT analysis of excised tissue specimens can distinguish between normal and cancerous tissues by identifying the heterogeneous and disorganized microscopic tissue structures indicative of malignancy. In this translational study involving 35 patients, a handheld surgical imaging OCT probe was developed for in vivo use to assess margins both in the resection bed and on excised specimens for the microscopic presence of cancer. The image results from OCT showed structural differences between normal and cancerous tissue within the resection bed following WLE of the human breast. The ex vivo images were compared to standard post-operative histopathology to yield sensitivity of 91.7% (95% CI: 62.5–100%) and specificity of 92.1% (95% CI: 78.4–98%). This study demonstrates in vivo OCT imaging of the resection bed during WLE with the potential for real-time microscopic image-guided surgery.

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

“…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].…”

“…Large-scale clinical trials were conducted to evaluate the efficacy and safety of commercial femtosecond laser modules with OCT guidance [193], [194] and the researchers reported that OCT aided in detection of the anterior and posterior lens surfaces and iris boundaries [193], and that femtosecond laser cataract surgery with OCT guidance resulted in comparable complication rates to manual surgery [193,194]. image-based detection of cancer in in vivo resection beds and excised tissue using histopathology as a gold standard [94] (Fig. 14).…”

“…They applied tabletop [195] and handheld SD-OCT [94] systems, in addition to a commercial SS-OCT HHOCT [95], to image pathologic specimens and resection beds intraoperatively for real-time margin analysis. Blinded raters demonstrated a mean sensitivity of 91.7% and specificity of 92.1% for OCT …”

How Close Are We to Real Time Optical Margin Control in Head and Neck Oncologic Surgery?

“…This essentially acts like a low energy laser based "optical ultrasound" when evaluating tissue. OCT has been applied in intraoperative margin detection in cutaneous, vulvar, breast, and gastro-intestinal malignancy [47][48][49][50][51] . OCT has been examined in several diagnostic/detection applications in the head and neck such as larynx, oral, and esophageal cancer however studies examining the ability of OCT to determine the accuracy intra-operative margins are less common [20,21,49,[52][53][54][55][56][57] .…”

Computational optical coherence tomography [Invited]

“…Since its introduction in the early 1990s, optical coherence tomography (OCT) has become an invaluable modality with widespread biomedical applications [1][2][3][4][5][6][7][8]. In particular, it is now a standard of clinical care in ophthalmology [9].…”