Optical Imaging Probe Proves Successful

A newly-developed handheld probe, shown at bottom left, will enable surgeons to image and assess tissue in a patient’s tumor cavity during surgery. Photo courtesy Diagnostic Photonics Inc.

A handheld optical imaging surgical probe develped by Beckman Institute researcher Stephen Boppart, will give doctors performing procedures on cancer patients the ability to image tissue image and assess tissue in the patient’s tumor cavity during surgery.

Surgeons can use imaging for localizing lymph nodes prior to surgery, and for assessing tissue after surgery. Now, a new technology in the form of a handheld optical imaging surgical probe, will give doctors performing procedures on cancer patients the ability to image tissue in situ – meaning that, for the first time, they can image and assess tissue in the patient’s tumor cavity during surgery.

This intraoperative surgical method is being developed by Beckman Institute researcher Stephen Boppart and his collaborators as part of ongoing research involving non-invasive or minimally invasive imaging methods using optical coherence tomography (OCT).

In a paper for the Annals of Surgical Oncology, Boppart and his collaborators report on using OCT for the first-ever longitudinal study of 3-D trans-capsule imaging of intact lymph nodes in a pre-clinical model. The next step is to use the technology in the operating room.

The paper, Three-dimensional optical coherence tomography for optical biopsy of lymph nodes and assessment of metastatic disease, reports that the OCT device provided high-resolution images showing “image-based biomarkers indicative of reactive and metastatic changes over the course of 9 days in a rat metastatic tumor model.” 

The results showed microstructural changes during metastatic infiltration, an important phase during the spread of a tumor. With penetration depths of 1 to 2 millimeters, the OCT system was able to differentiate normal, reactive, and metastatic lymph nodes based on the microstructural changes. The results demonstrate, the researchers wrote, “the potential of OCT as a technique for intraoperative, real time in situ 3-D optical biopsy of lymph nodes for the intraoperative staging of cancer.”

The technology is being used in operating rooms at Carle Foundation Hospital in Urbana.

The work is part of two National Institutes of Health grants, including one for intraoperative imaging and one $5M grant for developing handheld imaging devices for primary care providers. In the latter project, the OCT imaging technology is being integrated with current instruments, such as surgical probes, or an ophthalmoscope used for eye exams, for real-time tissue assessments. The goal is to create a versatile diagnostic tool that can be used by physicians and other healthcare providers from many different fields.   

“We are trying to build a small, handheld unit that has multiple tips,” Boppart said. “What’s collected is 3-D digital data that can image several millimeters into tissue and at micron-scale resolution.

“For detecting disease early, the primary care physician is the best person to screen the general population for disease.”

The intraoperative OCT system for breast cancer surgery being tested could help eliminate the need for multiple surgeries in order to determine if all of a tumor has ben removed.

Boppart has been developing the technology in the Biophotonics Imaging Laboratory he heads at Beckman Institute and at a company, Diagnostic Photonics Inc., that was created as a research partnership to advance the technology for biomedical use.

At Beckman, Boppart is Co-chair of the Integrative Imaging research theme and a member of the Bioimaging Science and Technology group. He is a faculty member in the departments of Electrical and Computer Engineering and Bioengineering, and has affiliations with the Department of Internal Medicine in the College of Medicine, and the Micro and Nanotechnology Laboratory