New treatment methods in pancreatic cancer
Due to the limited benefit of existing treatment methods in pancreatic cancer, some new treatment methods have been tried. The most promising of these is the percutaneous ablation. In this method, under the guidance of ultrasound and computed tomography, special needles are placed into the tumor in the pancreas from the skin and the tumor is killed by methods such as heating and freezing. The effectiveness of the treatment can be further increased by adding intratumoral immunotherapy to this method. 

Percutaneous ablation methods in pancreatic cancer and our own experience
The pancreas is considered not to be an ideal organ for percutaneous ablations because it is a small organ and is surrounded by structures that may be damaged by ablation, such as the arteries, veins and bowels.  Thermal methods that use heat such as radiofrequency and microwave were first used in in the 2000s. Although they were successfully applied by some centers, including ours, these methods have not been popular as they aim to kill the tumor by heating which is likely to cause complications such as fistula, infection and adjacent tissue damage in a sensitive organ like pancreas. At our centers, we prefer radiofrequency and microwave in the treatment of liver metastases in stage 4 patients rather than the primary pancreatic tumor itself. 

















Another ablation technique that has become popular in pancreatic cancer in recent years is the irreversible electroporation also known as Nanoknife. In this method, 4-5 electrodes are placed on the edges of the mass in the pancreas, under ultrasound and tomography guidance, and a short but very high electric current (such as 3000 Volts, 50 Amperes) is applied to the electrodes in turn. This electric current permanently opens some holes in the cell wall (poration) and causes cell death by increasing wall permeability. The most important feature of nanoknife ablation is that it is theoretically more effective on the tumor tissue around large vessels and causes less damage to critical tissues such as vessels and bile ducts. Therefore, it was thought to be a promising method in pancreatic cancer.

Nanoknife (IRE) treatment was used intensively by our team between 2012 and 2015, and our team was given the best presentation award in two consecutive radiology meetings.  

Click for our Nanoknife ablation TGRD congress first prize in pancreatic cancer
Click for Nanoknife ablation in pancreatic cancer, our first prize from the Turkish Radiology Association

However, in our experience, Nanoknife is technically a more difficult and risky procedure than other ablations, because 4-5 needles must be placed parallel to each other into the edges of the tumor without passing through organs such as vessels, ducts and bowels and therefore, it requires a high level of experience. In addition, it requires general anesthesia and intensive care as hypertensive crises and arrhythmia may occur during the procedure. And finally, it is more expensive than other ablation methods. For these reasons, it is no longer our first choice in pancreatic tumors.


















Cryoablation (freezing) treatment
It is by far the most preferred ablation method for pancreatic cancer in our centers. For cryoablation, we place 1-2 cryoprobes into the pancreatic mass under local anesthesia, with ultrasound and tomography guidance. When the device is activated, it is seen that an ice ball forms around these probes and engulfs the tumor mass located in the pancreas. After the 10 minutes freezing and thawing processes, which are done twice the probes are removed. The ablations may be repeated until the whole tumor tissue is treated. Cryoablation can be performed with local anesthesia only owing to the natural anesthetic effect of cold, or with additional sedation. During the procedure, it is easier to protect the surrounding tissues as the ablation area can be seen as an iceball on tomography and ultrasound.   


















Why do we prefer cryoablation in pancreatic cancer?
1. Cryoablation is performed through the needle puncture under local anesthesia, the procedure only takes 1-2 hours.
2. There is very little pain during and after the procedure. The natural local anesthetic effect of cold prevents pain.
3. During the procedure, the frozen area is clearly seen on ultrasound and tomography. This area can be reduced or enlarged as desired to achieve maximum effect without damaging the surrounding tissue.
4. The patient can return to his normal life on the same day or after staying in our center for one day. 5. Cryoablation is one of the most effective methods for relieving pain due to pancreatic cancer. After cryoablation, the patient's pain decreases, making it easier for the patient to receive other treatments such as chemotherapy.
6. Approximately 80-90% of the mass in the pancreas can be killed by freezing with cryoablation. If necessary, long-term local treatment can be provided by supporting radiotherapy and intratumoral immunotherapy methods. 
7. If the cancer recurs, cryoablation can be repeated multiple times in the same area.