New research further validates the use of the Cellvizio platform for endoscopic, needle-based, ultrasound-guided, confocal laser endomicroscopy as an effective means to perform optical biopsies on pancreatic cysts. Studies are supporting it as an ideal tool for imaging biomarkers in the diagnosis of pancreatic cysts as well. Sacha Loiseau, PhD, Mauna Kea Technologies founder and CEO, explained the implications of the latest research his company has conducted.
“This new peer-reviewed study […] provides further validation of the application of Cellvizio [Mauna Kea Technologies] needle-based CLE in the diagnosis of pancreatic cysts,” Loiseau said during a press release. “There is a significant opportunity for clinicians to use optical biopsy with Cellvizio in the often-challenging task of diagnosing pancreatic cysts, allowing them to make faster diagnoses and better treatment decisions to achieve better outcomes for their patients.”
Somashekar Krishna, MBBS, and his research team from Ohio State University’s Wexner Medical Center operated a prospective study out of the center’s gastroenterology, hepatology and nutrition division wherein they attempted to discern whether or not they could reproduce in vivo nCLE patterns via an ex vivo setting, and they compared their findings to surgical histopathology.
Adam Leitenberger, a Healio correspondent on gastroenterology, explains his team’s efforts saying, “they evaluated 10 patients (mean age, 53 years; 50% men) who underwent in vivo nCLE and ex vivo probe-based CLE of their surgically resected pancreatic cystic lesions.” Two intraductal papillary mucinous neoplasms were confirmed via surgical histopathology, as were two cystic neuroendocrine tumors, three mucinous cystic neoplasms, two squamous lined pancreatic cystic lesions and a serous cystadenoma.
The team perused Ohio State Medical Center’s EUS database to find every patient who had EUS-guided nCLE to evaluate pancreatic cystic lesions from 2013-16. Six international endosonographers who had experience with nCLE reviewed videos of 23 patients’ pancreatic cystic lesions after being masked to the clinical data. These patients had received surgically confirmed diagnoses whereas six others were clinically diagnosed. Within two weeks, they looked over the same images but in a different order.
“EUS-guided nCLE diagnosed mucinous pancreatic cystic lesions with 95% sensitivity, 94% specificity and 95% accuracy, and with ‘almost perfect’ interobserver agreement and intraobserver reliability,” Leitenberger reports. “Further, the technique diagnosed non-mucinous lesions with 99% sensitivity, 98% specificity and 98% accuracy, and also with ‘almost perfect’ interobserver agreement and intraobserver reliability.”
Krishna and his team concluded that in vivo nCLE patterns were identical to ex vivo pCLE patterns for all the major neoplastic pancreatic cystic lesions, and the two methods correlated as expected with surgical histopathology. “This study demonstrates that EuS-nCLE provides in vivo diagnostic imaging of large [pancreatic cystic lesions] with a high diagnostic accuracy,” concluded Krishna and his colleagues.
“The evaluation of PCLs continues to pose a challenge. In uncertain clinical situations, a composite approach including clinical features, imaging characteristics, cyst fluid [carcinoembryonic antigen], cytological examination, and nCLE is necessary,” the team found according to Leitenberger.
They also wrote that the endosonographers identified “novel vascular patterns and suggested a reasonable classification of nCLE patterns of [pancreatic cystic lesions] facilitating their diagnosis,” and they supplemented their observation with the fact that their findings still need further confirmation from bigger multicenter studies. Loiseau said, “The results from this well-designed independent, international study, confirm the unmatched level of sensitivity and specificity for characterizing cystic lesions of the pancreas.
“Millions of Americans have a pancreatic lesion and tens of thousands will undergo an unnecessary interventional procedure, including surgeries. These results confirm that, as we have seen with other large studies, a majority of these procedures could be avoided with a single Cellvizio procedure performed during an [EUS] examination.”
“The correlation of histopathology and the reproducibility of in vivo and ex vivo CLE imaging patterns supports the application of EUS-nCLE as an imaging biomarker in the diagnosis of PCLs,” the team wrote. The team also observed a need for more research to determine the efficacy of EUS-nCLE both by itself and in tandem with cyst fluid molecular biomarkers.
Leitenberger explains that “A combination of two biomarker tests differentiates benign serous cystic neoplasms from potentially malignant pancreatic lesions with ‘near perfect’ accuracy, allowing patients who test positive to avoid additional screening and surgery.”
Other studies not so dissimilar to that of Krishna’s research team also support similar technology and research. C. Max Schmidt, MD, PhD, FACS, and colleagues combined a protein closely associated with the formation of blood vessels that also tends to be upregulated in tumors with cyst fluid, carcinoembryonic antigen, which is a protein associated with the adhesion of cells and that is also proliferated in correlation with certain cancers. Testing all the proteins individually in this study accurately differentiated the majority of pancreatic lesions from serous cystic neoplasms with an efficacy comparable to that of gold-standard pathologic testing.
“Every day, surgeons follow patients who have pancreatic cysts that have no risk of cancer but are still worrisome,” said Schmidt, biochemical/molecular biology and surgery professor at Indiana University School of Medicine during a press release. “They perform surgery or conduct diagnostic tests just to make sure they’re not wrong. With VEGF-A and CEA, we believe we may have invented a test that can help that group of patients who don’t have a risk of cancer get off the testing cycle and avoid surgery which, in and of itself, has a risk of mortality or complications.”