Dr Kennedy Discusses IMI for Nonpalpable Tumors

In an interview with Oncology Learning Network, Gregory T. Kennedy MD, Resident in General Surgery, Hospital of the University of Pennsylvania, discuss the background, findings, and clinical significance of an original investigation on targeted intraoperative molecular imaging for localizing nonpalpable tumors and quantifying resection margin distances.

What existing data led you and your co-investigators to conduct this research? 

We know that early-stage tumors for a number of different cancer types can be challenging for surgeons to identify by eyesight or feel alone. If surgeons can’t find and remove all of the tumor cells, then patients do much worse in terms of the course of their cancer and their survival.  

We have been trying for several years to develop a technology called intraoperative molecular imaging in order to help surgeons find tumors that they can’t clearly see or feel. Intraoperative molecular imaging involves giving patients a fluorescent tracer on the day prior to surgery. This tracer is targeted to cancer cells and makes them “glow” when imaged with a specialized camera in the operating room. Surgeons can then find and remove all of the glowing cancer cells to allow a more complete cancer surgery. 

This study is the culmination of our efforts to develop intraoperative molecular imaging.

Describe your study and its findings. Were any of the outcomes particularly surprising?

We enrolled 40 patients with a lung nodule suspicious for cancer, and with findings on CT scan that suggested it might be difficult to see or feel in the operating room. We administered these patients a tumor-targeted fluorescent tracer on the day before surgery and then tried to find the cancers only using traditional methods of visual inspection and palpation.

We then used a specialized near-infrared camera to detect the fluorescent tracer that had localized to the cancer cells and made them “glow.” We compared how many tumors were identified by traditional methods to the number of tumors that were detected with our novel technology.

The outcomes that were most surprising were that intraoperative molecular imaging found 90% of the tumors in the operating room, whereas traditional visual inspection and palpation only found 55%. Moreover, we found that intraoperative molecular imaging could determine the exact distance between the tumor and the surgical margin, allowing surgeons to know if they had taken enough tissue for a complete resection.

What are the possible real-world applications of these findings in clinical practice?

This technology can help surgeons more completely remove cancers in the operating room by identifying disease that can’t be detected by their eyes and hands alone. It can also help determine if they have taken a large enough margin around the cancer in order to reduce rates of recurrence.

Do you and your co-investigators intend to expand upon this research?

Yes, our group and others have ongoing clinical trials of this technology in a range of cancer types using different tumor-targeted tracers. We hope that this technology will be adopted throughout the field of surgical oncology, if its clinical efficacy is validated in other clinical trials.

References:
Kennedy GT, Azari FS, Bernstein E, et al. Targeted Intraoperative Molecular Imaging for Localizing Nonpalpable Tumors and Quantifying Resection Margin Distances. JAMA Surg. Published online August 25, 2021.doi:10.1001/jamasurg.2021.3757