3-D SENSOR: Professor Petr Brůža holds a prototype of the fluorescence LiDAR camera. (Courtesy Photo)

Surgeons initially use computer tomography (CT) or magnetic resonance imaging (MRI) scans to gauge tumor locations and shapes, but during surgery typically rely on vision, touch, and training to remove tumors and leave healthy tissue intact. “We can use pulses of light to range the distance and position of cancerous cells in tissue, similar to how radar detects the position of planes in the air,” says Professor Petr Brůža. 

The concept of using a depth-sensing camera—leveraging 3-D imaging sensor and pulses of light to localize tumors—came to Brůža in 2020. He assembled a team of biomedical engineers, including Professor Kimberley Samkoe, one of the principal investigators of Dartmouth’s fluorescence-guided surgery project, and Professor Edoardo Charbon in Switzerland, who provided an ultra-fast sensor for experimentation. 

The team’s research—“Single-photon avalanche diode imaging sensor for subsurface fluorescence LiDAR”—was featured on the cover of Optica last winter. Now, Dartmouth engineers are testing a novel fluorescing drug designed to bind to cancer and highlight affected areas when irradiated by red light. The camera is being integrated into a compact surgical microscope to assist surgeons in navigating through sensitive tissue to ensure no tumor is left behind.

This article appeared in the Spring 2022 issue of the Dartmouth Engineer magazine.