Researchers Develop New Tool to Help Brain Surgeons in Operating Room

From left, Nathalie Agar, Isaiah Norton, Alexandra Golby and Sandro Santagata comprise the BWH DESI mass spectrometry team.

Distinguishing the border between normal and cancerous brain areas can often be difficult for surgeons attempting to remove tumors. But a new tool may change this, allowing more comprehensive testing of brain tissue during surgery to help surgeons quickly make the call between healthy and cancerous tissue.

So far, the tool has successfully identified the cancer type, severity and tumor margins from tissue samples of five brain surgery patients, according to a new study conducted by researchers from BWH’s departments of Neurosurgery, Radiology and Pathology, and Purdue University.

“Tumor tissue within the brain often closely resembles normal brain tissue and may have indistinct boundaries, so it is difficult to determine where tumors end and normal brain tissue begins,” said co-study author Alexandra Golby, MD, director of Image-Guided Neurosurgery in BWH’s Department of Neurosurgery, and clinical co-director of BWH’s Advanced Multi-Modality Image Guided Operating (AMIGO) suite.

“During surgery, we want to preserve as much functional brain tissue as possible, especially when a tumor is in a critical area of the brain, such as those that support movement, speaking or vision.”

Today’s surgical methods rely on a surgeon’s trained eye along with the help of an operating microscope and brain image scans taken before or during surgery.

According to co-study author Sandro Santagata, MD, PhD, of BWH’s Department of Pathology, examining frozen brain tissue specimens (which are transferred from the operating room to a pathology laboratory) takes about half an hour—a long time to wait during surgery. This problem is magnified when surgeons need information from multiple samples during the course of a procedure.

A Tool in the Works

Attempting to develop a tool that would allow surgeons to address the time delay that occurs during tissue analysis, researchers tested an imaging tool known as “desorption electrospray ionization” (DESI) mass spectrometry.

DESI mass spectrometry was initially developed by researchers at Purdue University. The BWH research team initiated a collaboration with Purdue University to use this technology to test brain tissue samples from patients who underwent surgery in the AMIGO suite and in standard BWH operating rooms.

In the study, surgeons removed 32 specimens from patients during surgery, which were later analyzed by both the new tool and standard pathology methods to test for accuracy. The researchers used DESI mass spectrometry to evaluate the distribution and amounts of fatty substances, called lipids, within the brain tissue specimens. A software program developed by the team then used the results to characterize the brain tumors and detect boundaries between healthy and cancerous tissue.

“The new tool is able, in a matter of seconds, to identify and classify many types of brain tumors, and to recognize tumors that are likely to behave aggressively,” said Santagata. “Accessing this type of information at a pace that is more compatible with the pace of surgery could be a big plus for patient care.”

Next Steps

The researchers plan to improve the classification software. BWH has set up DESI mass spectrometry technology in the AMIGO suite and plans to test it to detect brain and breast cancer margins during surgery.

“This approach could lead to real-time, image-guided surgery,” said Nathalie Agar, PhD, director of the Surgical Molecular Imaging Laboratory in BWH’s Departments of Neurosurgery and Radiology, and co-lead study author. “Such extensive and detailed information about brain tissue that could lead to more precise tumor removal was previously unavailable to surgeons. In addition, having access to a detailed diagnosis on the day of surgery could help an oncologist more efficiently design the course of post-surgery therapy.”

A new imaging tool has successfully identified the cancer type, severity and tumor margins in patients who underwent brain surgery in BWH’s AMIGO suite (pictured above).