Prostate cancer is the most common type of malignant tumor in men. Patients faced with this diagnosis face a difficult decision – which method to choose to fight the disease. Gernot Bonkat, Doctor of Medical Sciences at alta uro clinic – one of the leading urological clinics in Switzerland, under the guidance of Professor Alexander Bachmann – talks about the advantages of the modern NanoKnife® focal treatment.
– Dr. Bonkat, can you explain to our readers what the term «focal therapy» means?
– This type of treatment has been used for many years. Its main advantage is that it affects only a part of the organ that is impaired by the tumor. Thus, focal therapy does not damage healthy tissues. For example, when treating breast cancer, this method allows us to preserve the breast itself, and this is very important for a woman. In case of the prostate gland, traditional therapy seeks to completely remove it or treat with radiation. These methods are tried and tested, and for some patients they are still considered to be the most effective. Among the disadvantages is a high probability of side effects. So, with radical therapy, the chance of erectile dysfunction is 30 to 90%, and of incontinence and colon complications, from 5 to 20%.
Fortunately, medical advances allow us to use different approaches to treatment. The development of medical technology and equipment has provided us with enormous opportunities. Now you can treat prostate cancer with a precise focus, and at the same time preserve not only the tissue and the nerve trunks around the tumor, but also the prostate itself.
– You work with a NanoKnife® that performs so-called ‘irreversible electroporation’ (IRE). What is the difference between IRE and other types of focal therapy?
– To date, this method has been recognized by the medical community as the most promising, as it allows us to completely cure cancer without disabling the patient, as opposed, for example, HIFU (High Intensity Focused Ultrasound) therapy, where malignant cells are destroyed by thermal exposure. This effect can be compared with that of a hot stove – the heat that comes from the stove can be felt at a considerable distance from the stove itself. In a similar way, the thermal effect of HIFU therapy is not limited to a tumor; it also affects the tissues that surround it. As a result, structures adjacent to the prostate are also destroyed, including neurovascular bundles responsible for erection; muscle contracting the bladder; the bottom of the bladder; and the colon. Similar effects often occur after exposure to low temperatures (cryotherapy).
With irreversible electroporation this does not happen, as this method does not involve thermal or radiation exposure. To date, no patient at our clinic has suffered such side-effects as urinary incontinence, and the incidence of impotence and erectile dysfunction after IRE is significantly lower as compared with other methods of treatment. Moreover, impotence is quite often reversible – the sexual function is restored after a while. Therefore IRE, in our opinion, surpasses other types of focal therapy, even for purely physiological reasons.
– Please tell us more about irreversible electroporation. What is the foundation of it?
– The mechanism of the IRE effect is the induction of pores into the outer shell of the cell, which leads to the death of cancer cells. In this case, the tissue does not heat up and is not irradiated – pore formation is caused by very short, very strong electrical impulses. The NanoKnife. serves as the source of such impulses.
The effect of impulses of various power settings continues for only a few microseconds, but this is enough to destroy the shell of the cancer cell and to cause the death of the tumor. The NanoKnife. cuts the shell of the cell – the membrane – so it is also known as the “electronic scalpel”. As I’ve said before, during this procedure, healthy tissues are not injured and the dead cells are then replaced by healthy ones.
– How do you perform the procedure, and how long does it last?
– As opposed to the standard procedure, with the IRE method doctors do not need to make any incisions – the abdominal and pelvic cavities are not opened. Instead, electrodes are inserted into the prostate through small holes in the perineum. They are positioned so that the electric fields that they generate affect only the areas of the prostate in which the cancer cells are located.
The procedure is performed under general anesthesia and lasts, as a rule, less than an hour. After the patient recovers from the anesthesia, he will experience mild muscle pain, at most, which should not cause any concern. The patient is discharged from the hospital on the same day.
– What are the other advantages of IRE, in addition to the absence of side effects?
– First of all, as I mentioned, there is no lengthy post-surgical recovery period, and therefore the stay in the clinic is limited to one day. On the next day, the patient can return to his normal life without experiencing pain.
The second big advantage is that after the IRE procedure, it is still possible to apply other methods of therapy. If for some reason the treatment did not bring about the expected result, then it is always possible to resort to surgery, radiation, or to the HIFU method.
Thirdly, IRE can be carried out repeatedly, when treating metastases or recurrences of cancer. This is unlike radiation therapy, for example, with which it is almost always impossible.
In addition, the NanoKnife. can be really helpful for patients with advanced and severe cancers, which for various reasons cannot be treated by conventional methods.
– It seems that the method is pretty much perfect. Does it have any disadvantages?
– If the diagnosis and treatment are properly conducted, I honestly do not see any. However, due to the fact that IRE began being practiced quite recently (less than 10 years ago), we do not yet have long-term statistical data. We do not yet know how this therapy affects overall survival.
– How can a person who has been diagnosed with prostate cancer understand which treatment method will be best for him?
– This question is not so easy to answer. I do not want to bore the readers by talking about Gleason scale indicators, degrees of differentiation and models of tumor development. I will only say that intensive communication with the consulting doctor is very important for those who are affected by the disease.
The choice of treatment method depends, in the main, on the stage at which the disease is detected. In the early stages, with careful observation, it is actually possible not to treat the tumor at all. This principle is called “active observation”. Here we are not talking about giving up long-term treatment – we should just observe how it evolves.
In making a decision, it is also important to consider whether the diagnosis is primary or a relapse. If the tumor has been detected at an early stage and is limited only to the area of the prostate gland, you can choose from the range of treatment methods. But patients whose disease is progressing must weigh up all the pros and cons before deciding on something. At our clinic, we conduct a full diagnosis for the patient and recommend the treatment that suits him best.
– What diagnostic methods are used in alta uro?
– The main one is magnetic resonance imaging (MRI), due to which the accuracy of detection of prostate cancer in the highrisk zone is approximately 85%. But MRI is able to determine only a macroscopic foci of a tumor, of 2–3 millimeters. To confirm a microscopic foci, we make a so-called transperineal fusional biopsy and a biopsy of the prostate gland cartilage. During this procedure, through an incision in the perineum, tissue samples are taken every five millimeters. After that, all the information is analyzed by a special computer program, and thus we get an accurate histological model for planning further treatment.
In general, the diagnosis before focal therapy is more extensive than in the case of radical treatments.
– Clearly, the role of the attending physician in this situation is enormous. What signs can help one recognize a good urologist?
– The decisive factor here is their experience and the number of patients cured following the corresponding diagnosis. One can also inquire as to whether he/she takes into account medical provisions of a recommendatory nature, and whether he/she participates in clinical trials.
It is important that the doctor and the clinic where he/she works are able to offer the patient various therapies and provide him with all the necessary information on this topic.
Speaking of alta uro, this is the first Swiss clinic to use the method of irreversible electroporation. This happened very recently, at the beginning of 2017. Before we started working with it, naturally we studied the technique thoroughly. Along with intensive theoretical training, our doctors received training from leading specialists from England and Germany. Our first treatment results are more than promising – there have been no relapses so far.
– Is it possible to say that IRE will soon completely replace such severe types of treatment as prostate removal and radiation therapy?
– Hopefully, the NanoKnife. therapy or a similar gentle therapy will displace radical therapies of prostate cancer in the future. As mentioned above radical methods entail significant side effects. In addition, there are considerable recurrence rates and the question remains whether radical therapies bring a survival benefit for the individual patient at all.
– And does the cancer go away for good after treatment with a NanoKnife®?
– Ideally, yes. Of course, it is possible that after a while the patient might develop a tumor again. But even in this case, all is not lost – the doctor has the opportunity to repeat the IRE, and also to resort to radiation treatment or surgery. The advantage of focal therapy is not only that it has fewer side effects, but also that it leaves all the other options open to the patient.
Gernot Bonkat
Studied medicine at the Universities of Munich and Würzburg in Germany. In 2014, Dr. Bonkat attained the position of Associate Professor at the University of Basel, Switzerland. In 2016, together with his mentor and partner Professor Alexander Bachmann, he founded the alta uro clinic in Basel. Dr. Bonkat is an active member of various urological societies, including the European Association of Urology, the Endourological Society, and the German as well as the Swiss Association of Urology. Since 2015, he is heading the Guideline panel on Urological infections of the European Association of Urology. He is a pioneer in using the latest diagnostic methods in the field of infections of the genitourinary system, as well as in tuberculosis of the genitourinary tract. Since 2009, Dr. Bonkat has been a senior researcher at the Biomechanics and Biocalorimetry Laboratory of the University of Basel. In 2012, he worked as a principal investigator at the Department of Urology at Tygerberg Hospital in Cape Town, South Africa. He is the author of more than 150 articles, books and reports.
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