​Advantages and disadvantages of argon-helium knife treatment

Argon-helium cryotherapy is a medical technology that uses ultra-low temperature freezing to eliminate tumors. It can achieve minimally invasive treatment of tumors and is suitable for the early, middle and late stages of tumors. This is a very advanced medical technology with a surgical success rate of up to 90%. It is also suitable for elderly people and young children. Since the argon-helium cryotherapy effect is so good, are there any pros and cons of the treatment? Come and find out with the editor.

The argon-helium knife is different from the gamma knife, proton knife, etc. It does not emit radiation lasers, etc. Its working principle is the Joule-Thomson principle: that is, when the gas is sprayed from a higher pressure area into a lower pressure area through a narrow micropore, it will be throttled. Most gases will cool down when throttled, such as argon and oxygen. However, for some gases, such as hydrogen and helium, the temperature actually rises.

The argon-helium knife is a physical method in which a needle is inserted into the nodules in the chest and lungs. The temperature is rapidly lowered, then rapidly raised, and then lowered again, and repeated cycles of hot and cold (if necessary, only cold temperatures can be used without high temperatures) are used to kill the tumor and its surrounding tissues, causing them to lose their vital characteristics and become an inorganic small mass that gradually calcifies.

Because there is no need to cut open the chest cavity, the wound is smaller than that of manual surgery. Because a needle needs to be inserted (if the nodule is too large, multiple needles are inserted into one nodule at the same time) into the nodule flesh of the chest and lung, there is a needle hole, that is, there is still a wound, and it takes several days to recover. When the needle is inserted and removed, pneumothorax effusion is likely to occur (the gas and liquid in the chest and lungs run along the needle hole to places where they should not go). Therefore, after the operation, you need to stay in the hospital to drain the fluid and exhaust. If the situation is not serious, you can be discharged in a few days. If pneumonia unfortunately occurs, the time will be extended to weeks.

Before immunotherapy, especially PD1, came out, the argon-helium cryotherapy quickly became popular because it is a minimally invasive surgery with little bleeding and definite efficacy. All tumors that are frozen die. The surgery is fast and the hospital stay is short, saving a lot of unnecessary expenses. More and more hospitals (nearly 100 in China) are equipped with argon-helium cryotherapy as a tumor ablation treatment technology, and it is used for liver cancer, lung cancer, pancreatic cancer, prostate cancer, kidney tumors, breast cancer, etc. The lungs, liver, breasts and even limbs are all used.

Because the needle tip of the argon-helium knife can freeze the diseased tissue to -120℃~-165℃ in a dozen seconds when argon is used, and it can quickly reheat and heat up when helium is used, and the tumor ice ball can be thawed quickly. The speed, time, size and shape of the cooling and heating can all be accurately set and controlled by a computer. In addition, multiple needles can be inserted into a large nodule at the same time, and there are no side effects such as radiation damage. For a time, the argon-helium knife was used in oncology, interventional medicine, radiotherapy, thoracic surgery, hepatobiliary surgery, general surgery, urology, neurosurgery, gynecology, dermatology, breast surgery, respiratory medicine, gastroenterology, otolaryngology and proctology, etc., and it almost occupied all departments of the hospital. Even benign tumors and tumors that cannot be distinguished as benign or malignant can be treated without any hesitation, and the patient will be frozen to death with a needle. Argon-helium cryotherapy, after all, is only a local surgical treatment. It does not regulate and restore the human body as a whole. It is unrealistic to expect that after the argon-helium cryotherapy is used to treat the lung metastases, there will be no recurrence or metastasis. In fact, after the largest nodule in the lung is removed, the second largest one quickly grows back. After the second largest one is removed, the third largest one and the many smaller ones around it start growing again. This is not only the limitation of the argon-helium knife, but also one of the considerations that must be repeatedly weighed before performing local tumor reduction surgery.

Although argon-helium cryotherapy has many limitations as mentioned above, it has one great advantage: the tumor cells in the lung nodules are repeatedly frozen and thawed, the cells rupture, and the cell membranes are lysed, and the tumor antigens that were originally shielded are released, triggering a sensitization chain reaction of the immune system. (From other major cancers besides sarcoma, it can be seen that within one or two weeks after undergoing argon-helium cryotherapy, the levels of tumor antigens such as CEA, AFP, and PSA in the patient's serum decreased significantly, confirming that the human immune function has recovered to a certain extent.) If immunotherapy such as PD1 is used at this time, the response rate of PD1 will be greatly enhanced.

On the one hand, the local tumor reduction of argon-helium knife reduces tumor burden and improves drug effectiveness. On the other hand, the systemic specific immunity induced by the treatment process will of course kill the largest nodules and produce antigens, which can stimulate PD1 to take effect.