NanoKnife Offers Promising Treatment Option for Locally Unresectable Pancreas Tumors
by Boris Kuvshinoff II, MD, MBA
Director, Liver and Pancreas Tumor Program
Patients with localized (stages I and II) pancreatic adenocarcinoma are typically offered surgical removal to give the best chance for long-term survival. Unfortunately, only about 20% of patients fall within these stage categories, and some of these are probably better characterized as "borderline resectable." A higher number of patients, up to 30-40%, will present with locally advanced (stage III) disease not amenable to surgical resection. This patient group typically undergoes chemotherapy or chemoradiation with an anticipated median survival of 10-12 months.
For patients with this more advanced disease, we have had some success in extending survival using NanoKnife IRE (Irreversible Electroporation). NanoKnife is a minimally invasive, probe-based technology that destroys tumors using pulsed, low-current, high-voltage electrical energy. This non-thermal electrical energy creates permanent “pores” in the cell membrane leading to irreversible swelling, apoptosis and cell death. Anywhere from two to six probes are inserted around a tumor under ultrasound or CT guidance. The technology does require general anesthesia and can be done via a percutaneous or operative approach. NanoKnife’s unique advantage, which allows use in the pancreas, is the preservation of major vascular and ductal structures.
The NanoKnife is generally considered for locally advanced pancreatic cancer due to major vascular involvement or for borderline resectable cancers where the risk of positive surgical resection margins are high. In the latter situation, NanoKnife can be used to treat the “margin” of the tumor and destroy tumor cells that might remain behind along critical arteries.
A prospective multicenter study of 54 patients with initially unresectable pancreas cancer compared IRE to propensity matched controls undergoing standard chemotherapy and radiation alone (1). The majority of the IRE patients also had chemotherapy and radiation. Nineteen of the patients had surgical resection and margin accentuation with IRE. The 90-day mortality in the IRE patients was 2%. In the comparison of IRE patients to standard therapy, an improvement in local progression-free survival (14 vs. 6 months, p = 0.01), and overall survival (20 vs. 13 months, p = 0.03) was seen.
RPCI Experience and Outcomes
Physicians at Roswell Park have now treated more than 25 patients with NanoKnife ranging in age from 45-85 years old. These include liver, pancreas and pelvic tumors. The pancreatic electroporation cases were done for locally advanced cancers, borderline resectable tumors with margin ablation, or in patients not cleared medically for pancreatectomy. All patients with pancreatic adenocarcinoma also had chemotherapy and radiation included in their multidisciplinary management. In eight pancreas cases with post-op CT, MRI or PET/CT follow-up, no visible tumor was able to be demonstrated at the site of ablation or resection.
Print or download a fact sheet describing the NanoKnife program at RPCI.
- Martin RC et. al. Ann Surg Oncol 2013, 20:3;S443-9.