The “gold standard of care” in the cure of Pancreatic Cancer, as small as that may be at around 10%, has been surgical resection via Whipple for Head of Pancreas Cancer or Distal Pancreatectomy for cancers arising in the Body or Tail of the Pancreas. One must have negative margins as surgical resection with positive margins confers virtually no significant survival advantage so the importance of a clear margin cannot be stressed enough. The technical ability to resect with negative margins has been a function of the percentage of circumferential vessel involvement. We categorize tumors as either:

Resectable– no vessel involvement

Borderline Resectable– less than 180degree

Unresectable-encasement

Resectable:

Patients who are non-metastatic and resectable may be resected either at the time of diagnosis or after a brief course of Neo-adjuvant chemotherapy for 12 weeks with the recently confirmed benefit that chemotherapy before resection translates into a slightly improved overall survival.

Borderline:

Resection is often possible in this group after a trial of chemotherapy or when performed jointly by a surgical oncologist and vascular surgeon capable of re-vascularization. When this is successful it results in survival rates equal to Whipple; Not better. There is nothing special about which vessels can be resected whether – Portal Vein(PV), SMV,SMA,Celiac Axis and Hepatic Arteries- they have all been resected and reconstructed with the same equal cure rate as the Whipple; which in the worst case scenario is 2-3x longer than the unresected state.

Nanoknife is an option in these cases and in a small percentage resection may become possible after nanoknife.

Unresectable:

Some cases unfortunately will never be resectable regardless of the amount of chemotherapy or radiation given and these should be considered for Nanoknife at the earliest possible time to enable the longest benefit from neutralizing the primary tumor’s ability to metastasize further. It is unlikely that an unresectable will be converted into resectable but nanoknife has even changed this. As a consequence whenever

vascular encasement is identified and chemotherapy has failed to render the patient resectable then Nanoknife should be considered.

NanoKnife 101:

The technology is optimized when used against small tumors and though there are some who still believe there is a size limit, this opinion is open to debate. The experience of the nanoknife surgeon, who ideally should be a pancreatic surgical oncologist- one who will be prepared to treat all the possible complications that can arise, largely determines the nanoknife’s feasibility and success. Please understand surgeon’s nanoknife experience is the key word. Do not assume the name of the center or a well renowned surgeon will be the solution to the problem you are seeking. Many do not endorse the procedure despite the research. Centers like MSKCC, MDAnderson, Mayo have limited experience with Nanoknife and many patients who have frequented those centers have either not been offered or denied without further discussion. Even Hopkins Surgeons have only been performing the procedure themselves in the OR for less than three years.

Every advanced stage 3 and 4 pancreatic cancer that is potentially a Nanoknife case must be individualized; there are no set rules. In my experience nanoknife is one of many available Ablation techniques to control the disease beyond simply adding the morbidity of an aborted procedure by “opening and closing” without accomplishing a positive. It enables me another option that can be made on the spot to avoid the circumstances of nothing accomplished by an aborted Whipple.

Surgical oncologists have always held open the opportunity to treat patients with many types of cancer who have minimal hepatic metastatic disease with success rates higher than can be achieved by chemotherapy and radiation. Recent reports over the past 3-4 years confirm the same to be true for pancreatic cancer. The word is getting around slowly; very slowly. More so as multimodality treatment approaches beyond the scope of the traditional medical oncologists dominion. Nanoknife has come to play an important role in these patients providing the opportunity of survival advantage without the morbidity and risks of Whipple. A possible win all around.

The following illustrates the difference between Borderline and Unresectable. Both are eligible for Nanoknife.

There is nothing special about which vessels can be resected whether – Portal Vein(PV), SMV,SMA,Celiac Axis and Hepatic Arteries- they have all been resected and reconstructed with an equal cure rate as the Whipple. The important point is to consider Nanoknife early in the decision tree especially once resection has been ruled out.

For more details please see my website or Facebook posts where other reports are posted highlighting the rationale for early nanoknife treatment in multimodality treatment has an advantage over late treatment.

RobertDonoway,MD,FACS