Optical biopsy tool successfully identifies cancerous pancreatic cysts

A new endoscopic procedure—light-scattering spectroscopy (LSS)—has 95% accuracy in the detection of benign and potentially cancerous cysts to better identify early pancreatic cancers, and can do so in real-time, according to researchers who have published their findings in a recent issue of the journal Nature Biomedical Engineering.

Of all major cancers, pancreatic cancer has the lowest survival rate, due in part, to the inability to detect it at early stages. Pancreatic cysts form in 1 in 50 adults, and roughly 20% of all pancreatic cancers develop from cysts. CT scans and MRI imaging can detect them, but provide only limited information. Fine-needle aspiration (FNA) is currently the optimal method for distinguishing benign cysts from potentially malignant ones, but this diagnostic has only a 58% accuracy.

“Unfortunately, patients with untreated malignant cysts have a median survival of just 3 months. Thus, there is an urgent need for the development of a new diagnostic method to accurately identify pancreatic cysts that need surgical intervention,” said senior author Lev T. Perelman, PhD, professor, Harvard University, and director of the Center for Advanced Biomedical Imaging and Photonics, at Beth Israel Deaconess Medical Center, Boston, MA.

LSS is comprised of an optical spectroscopic technique and fiber-optic probe that bounces light off targeted tissues to detect structural changes within it, and is compatible with clinical ultrasound-guided FNA.

Dr. Perelman and fellow researchers tested the accuracy of the LSS tool via analysis of reflected spectra from 13 cysts obtained from recent surgeries. In each cyst, data from LSS measurements agreed with data from microscopic exams of tissue samples in identifying benign versus malignant tissue.

These researchers then tested an LSS probe technique that was performed with the endoscopic ultrasound-guided FNA system. The aspiration needle was fitted with a retractable LSS fiber optic probe, and they used this to make diagnoses in 14 patients with pancreatic cysts undergoing standard FNA.

The cyst tissue was illuminated with white light, and researchers collected multiple readings of the reflected light in seconds. The LSS probe correctly identified the 9 patients whose cysts had been diagnosed as either cancerous or benign. The accuracy of their results in the remaining five cases will be assessed once post-operative tissue becomes available.

“Currently, it can take days to learn the results of the FNA cytological and biochemical evaluation,” said Dr. Perelman.

The LSS tool allows for real-time optical biopsy. Researchers plan additional development and testing of the LSS probe, and hope to develop the capability of LSS scanning of the entire internal surface of cysts.

“This rapid and inexpensive tool augments the current endoscopic technology in identifying benign pancreatic cysts and those with malignant potential at an early stage,” said Behrouz Shabestari, PhD, director of the NIBIB Program in Optical Imaging and Spectroscopy. “The method is highly accurate and offers great promise that may help doctors make critical surgical decisions.”

This work was funded in part by the National Institutes of Health through grants from NIBIB (EB003473) and the National Cancer Institute (CA205431).