NanoKnife, also called irreversible electroporation or short IRE, is a new and very low-side- effect treatment of prostate cancer. The patients treated with it are generally very satisfied with their treatment. Some urologists against it refer to missing long-term studies on this therapy and advise against as long as these study results are not yet available. They especially recommend the for years used treatment methods surgical removal of the prostate or radiation.
NanoKnife can be similar to an irradiation device not only against prostate cancer but also against tumors in the pancreas, the liver, the lungs, the kidneys, etc. In Germany, NanoKnife is used to treat liver tumors in Regensburg. The pancreatic cancer is being treated with NanoKnife at Klinikum Stralsund. In part, this is an open surgery, and tumor remnants are removed with NanoKnife. Here only the treatment of the prostate with NanoKnife is considered. This is mainly used as a focal therapy in prostate cancer, which have not yet exceeded the capsule. In the prostate center near Frankfurt, in Offenbach, NanoKnife is also used in more advanced tumors.
In about 40% of the treatments, the entire prostate is used NanoKnife porates, that means all cells of the prostate are destroyed. This is called complete ablation. It is thus removed as in surgery, the entire prostate, but minimally invasive with very few side effects. In advanced tumors, hormone therapy is used for about three months before surgery to reduce the tumor mass before surgery. So far, NanoKnife is only available at very few locations in Germany. Most of the operations have so far been carried out by the Prostate Center in Offenbach.
The clinic for prostate therapy in Heidelberg has also carried out a large number of treatments and, in cooperation with the manufacturer, offers training on the use of the NanoKnife device.
The CyberKnife therapy, a new treatment technique, can destroy even smaller metastases compared to NanoKnife, since the area to be treated can be even narrower here. Thus, after a NanoKnife therapy remaining metastases can still be removed.
With the NanoKnife therapy, several electrodes are inserted into the prostate through the dam. These electrodes generate extremely short current surges in the micro- to millisecond range with very high voltage in the region of the prostate. As a result, the membranes of the cells in the treatment area are porated or "perforated". The cell liquid flows out through these pores and the cell is no longer viable in a very short time. The porated cells are then broken down as in an internal injury from the body. This takes several months depending on the size of the treated area. If, for once, the reduction does not take place as expected, it may a scraping through the urethra (TUR-P) as done in a prostatitis. In the treatment area both cancer cells and normal cells in this way destroyed. Spared is the cell matrix of the healthy tissue. This makes it possible for the body to replace the porated cells with new, healthy cells. Unlike other therapies, a NanoKnife operation can delineate the treatment field to within a few millimeters, avoiding tissue damage beyond the edges. A repeated treatment of the same area would be technically possible.
Each NanoKnife therapy is preceded by the most accurate localization of the tumor. MRI images are taken with an endorectal coil or a 3D biopsy for smaller tumors. This rather expensive 3D biopsy is not required if the entire prostate is affected and should be completely derived. The procedure is performed under general anesthesia because the patient is not allowed to move during treatment. The anesthesia is performed as TIVA (total intravenous anesthesia) with propofol and other drugs. The patient does not suffer from nausea after nausea and wakes up relatively quickly.
The surgery involves first planning the placement of the electrodes based on the patient's ultrasound and MRI images.
The manufacturer of the NanoKnife device recommends to insert the electrodes with a grid or template, as it is also used in brachytherapy. However, the electrodes are placed without a grid, because then you can set them individually and the ultrasound recording a constant control of the placement allowed. The electrodes are then connected to the NanoKnife device to generate the surges. The preparation usually takes more time than treatment with the power surges. The surges are used only a few minutes. The entire procedure takes about two hours.
The day after surgery, the patient can usually leave the clinic. He then has to wear a catheter for another 10 to 14 days, as the prostate swells through the procedure and compresses the urethra. This depends on how large the volume of the prostate was and how extensive cells were destroyed with NanoKnife.
After surgery with NanoKnife remains after a focal treatment, as well after a complete ablation usually something healthy prostate tissue. z. From the prostate capsule. This results in the PSA value not reaching 0.01 ng / ml as after a prostatectomy, the result is a higher PSA value than the lowest measurement (nadir), similar to an irradiation. After the NanoKnife therapy a sporadic immune reaction of the body to still untreated cancer foci is observed. Scientific evidence for this reaction has so far only been shown in preclinical studies, ie not in patients. It is believed that both cell membrane fragments and the body-degraded, electroporated tissue, similar to a vaccine, enable the immune system of the body to attack the remaining tumor cells.
An evaluation of the treatments performed so far revealed very small side effects. The patient usually has no wound pain after the operation, as this surgery does not trigger inflammation.In all cases the patients remained continent. However, after the surgery often occurs a strong urge to urinate, which only passes after a few months. Especially after total ablation there is a larger amount of cells that have to be broken down by the body. This degradation can take six to twelve months. If the urethra is partially closed, the urinary stream is correspondingly weak. This can also lead to the urinary bladder can not be completely emptied, which leads to the urinary urgency mentioned.
Another possible cause is irritation of the nerves of the sphincter muscle as a result of surgery, as may occur after irradiation. These nerves then signal prematurely a strong urge to urinate. Retention of erectile function after surgery depends on whether a focal operation or a complete ablation has been performed. In both surgical procedures, only 7.1% of patients had erectile dysfunction. In a complete ablation of the prostate occur in about 45% of men temporary, lasting up to twelve months erectile dysfunction. These are reflected in more than 80% of those affected. If a hormone therapy to reduce the size of the tumor was performed before the operation, this will additionally impair the ability to have an erection even after the end of the hormone therapy for some time. At about 10% of complete ablations were found to have permanent impotence.
In a complete ablation is often dependent on the location of the tumor damage to the unavoidable nerves responsible for the erection Also the degradation of the dead Tissue after surgery can cause stretching and thus injury to lead these nerves.
A common side effect is urinary retention, which requires the use of a catheter for more than 14 days. The operation injures the urethra leading through the prostate gland and there must be a sufficiently large gap in the electroporated tissue for the urine. If the urinary retention is not yet after four weeks. This complaint can be remedied with a TUR-P. In a TUR-P, the undegraded cells are removed through the urethra (transurethral) under visualization (endoscopically) with an electric sling under anesthesia. A TUR-P laser treatment is not suitable after an IRE because the cells have already been destroyed by the IRE. The TUR-P requires a hospital stay of several days.
After a TUR-P you have a wound surface, which heals after some time. In general, you have to spare about four weeks. There may be pain when urinating and prolonged sitting can be uncomfortable. In addition, a NanoKnife operation uses water containing 5% glucose to maintain a safe distance to the gut and other organs. This water accumulates with blood due to gravity in the penis and scrotum (scrotum) and leads to swelling and a blue coloration of these organs. Medically, this side effect is harmless.
There are also international studies that confirm the great safety of NanoKnife therapy, which concludes: "NanoKnife can safely be used in patients with prostate cancer, and the majority of the side effects are transient."
At the SIR (Society of Interventional Radiology Annual Scientific) 2015 meeting, the experts present said, "NanoKnife is a new, effective treatment for prostate cancer therapy at various stages. It offers improved safety over other conventional therapies.