“I want to practice good medicine!” says Prof. Dr. med. Dr. phil. Dr. med. habil. Michael K. Stehling, who enjoys a reputation in his field that extends far beyond the country’s borders: particularly when it comes to prostate-related issues, he is regarded as exactly the right specialist. His high level of expertise is no coincidence – Professor Stehling has enjoyed extensive national and international training. Among other things, he was a Clinical Fellow at Harvard Medical School in Boston, Associate Professor of Radiology at Boston University, a Visiting Scholar at the University of California, Berkeley, and worked as a research assistant with Sir Peter Mansfield, Professor of Physics and winner of the 2003 Nobel Prize in Medicine. In 2010, Prof. Stehling founded the Prostate Center in Offenbach, now known as the VITUS Private Clinic. The center is regarded as a global leader in the minimally invasive treatment of prostate cancer, particularly using the IRE/NanoKnife® procedures.
Leading Medicine Guide: Professor Stehling, over ten years ago you founded the Prostate Center in Offenbach, now known as the VITUS Prostate Center. Has men’s awareness of prostate cancer and screening changed over the last ten years?
Prof. Dr Michael Stehling: The answer to that is complex. Generally speaking, it can be said that more and more men – and their partners – are seeking information online, regardless of medical recommendations. And that’s a good thing. Because what is offered as standard in prostate cancer screening in Germany is medieval: only the digital rectal examination, i.e. the palpation, is covered by health insurance. And this, to put it simply, is useless. There are studies showing that 97 per cent of all urologists’ index fingers are too short to palpate the entire prostate – and no study demonstrating any survival benefit from the digital rectal examination.
Leading Medicine Guide: That’s not good news …
Prof. Dr Michael Stehling: Yes, and the PSA test on its own causes more problems than it solves. Because in most cases, an elevated PSA level is not caused by prostate cancer, but by other factors, such as inflammation. However, when PSA levels are elevated, tissue samples are taken – in the standard procedure via the rectum, i.e. by transrectal ultrasound-guided biopsy – which results in one to two men in a thousand dying from antibiotic-resistant bacteria. In some countries, a ban on TRUS biopsy is therefore currently under discussion.
Leading Medicine Guide: Yet there is a reliable diagnostic procedure that is rarely used in this country.
Prof. Dr Michael Stehling: Yes. Magnetic resonance imaging of the prostate, also known as MRI. Prostate MRI makes it possible to detect or rule out clinically relevant prostate cancers with over 90 per cent certainty. And this has been the case for around 15 to 20 years. Experts are now certain that prostate MRI can prevent many unnecessary biopsies. In England and the USA, there are studies that clearly demonstrate the superiority of prostate MRI over the PSA test and biopsy. And prostate MRI is even more cost-effective than conventional screening tests for prostate cancer.
Magnetic resonance imaging (MRI) has the advantage over other imaging techniques, such as ultrasound, in that it can produce precise, high-resolution images of the prostate and surrounding organs with excellent multi-parametric soft-tissue contrast. MRI is therefore an excellent diagnostic method for detecting changes in the prostate at an early stage and classifying them accurately, in particular to distinguish between benign changes and cancer.
Furthermore, the examination is completely painless and involves no radiation exposure. The inside of the body is visualized layer by layer using magnetic fields.
Leading Medicine Guide: You worked for some time as a research assistant to Sir Peter Mansfield, who was awarded the Nobel Prize in 2003 for the development of magnetic resonance imaging. Today, you are one of the world’s most experienced experts in the field of clinical MRI. However, MRI is only slowly gaining acceptance in Germany as a diagnostic method for the early detection of prostate cancer.
Prof. Dr Michael Stehling: MRI scanning of the prostate has been the most precise and informative diagnostic method for prostate cancer for many years, including in the field of early detection. We have been doing this for 15 years and maintain that there is no alternative if one wishes to practice good medicine. In the meantime, MRI diagnostics of the prostate has finally made it into medical guidelines, albeit to a limited extent, so that established methods such as digital rectal examination, ultrasound and biopsy can remain in use for a while longer – some people simply do not want to give them up.
Of course, MRI can also be used to visualize all other tissues and organs of the body with precision, such as the spine, joints and the brain, as well as the heart and blood vessels. In breast cancer screening for women, MR mammography has far overtaken X-ray mammography, which is still used for breast cancer screening in Germany – this is the equivalent of prostate screening for men.
In our radiology department, we are able to offer ‘tailor-made’ MRI examinations tailored to the specific clinical question in order to arrive at the correct diagnosis. As far as I am aware, this is unique to us.
Leading Medicine Guide: You have a PhD in physics and two in medicine. To become a research assistant to Sir Peter Mansfield, you really have to know exactly what you want, don’t you?
Prof. Dr Michael Stehling: I am a very curious person and, of course, as a young man I was also very ambitious. After studying medicine and physics in Frankfurt, the most important step for me was to get out of Germany. Once I arrived in England, I suddenly understood how universities should really function and what I had missed out on in Germany. Personal support, in particular. I was initially fortunate enough to be supported in Manchester by Prof. Ian Isherwood. He then introduced me to Sir Peter Mansfield, the physicist and later Nobel Laureate in Medicine. Peter Mansfield then took a keen interest in me and offered me a position as a PhD student. This enabled me to work with him as a research assistant on the technical development of magnetic resonance imaging. Peter Mansfield is, alongside Paul Lauterbur, one of the two inventors of magnetic resonance imaging. I also greatly enjoyed this particular Anglo-American academic environment in the USA, where I worked at Harvard Medical School, Boston University and, most recently, at UC Berkeley.
Leading Medicine Guide: At the VITUS Prostate Center, you not only use state-of-the-art diagnostics, but also treat patients with specialized procedures, one of which is IRE, also known as the NanoKnife® procedure. Could you explain this in a bit more detail?
Prof. Dr Michael Stehling: IRE – irreversible electroporation – also known as NanoKnife® after the manufacturer – is a procedure that allows cancer to be treated in a way that is very gentle on tissue and organs. It was invented a good 15 years ago by Prof. Boris Rubinsky at the University of Berkeley in the USA. Boris and I have since become good friends. Our joint research and development in the field of electroporation – which has given rise to several medical technology start-ups – has helped us to gain a thorough understanding of IRE and to apply it successfully in the treatment of prostate cancer. With over 1,500 patients successfully treated, we at the VITUS Private Clinic are now global leaders in this field.
To understand why a new method for treating prostate cancer is needed at all, one must look at the established methods: surgery and radiotherapy. Not only are these ineffective – meaning they can cure prostate cancer in very few cases – but they also have severe side effects that irreversibly impair quality of life. In radical prostatectomy (RPE), the entire prostate is surgically removed. Unfortunately, to put it bluntly, a lot gets damaged in the process: after the operation, up to 50 per cent of all men are incontinent – they lose urine uncontrollably – and 70 to 80 per cent are impotent – they lose the ability to achieve an erection.
In contrast, the electroporation procedures we use at the VITUS Private Clinic – such as IRE, for example – cause hardly any side effects. IRE removes the cancer with a reliability comparable to that of surgery. However, electroporation procedures also trigger additional immune responses that stimulate the body’s own immune system to identify and destroy cancer cells throughout the body.
IRE is an interventional procedure, meaning it does not require surgery. Thin electrodes are simply inserted into the prostate via the pelvic floor, through which electrical impulses are then delivered to the tissue. These destroy cells in a targeted and selective manner. Other tissue components that do not consist of cells, such as fibers, remain intact. There are, however, different electroporation procedures: IRE stands for irreversible electroporation, which means that the treated cells are irreversibly, i.e. permanently, destroyed. Reversible electroporation (RE), on the other hand, only temporarily creates pores in cell membranes and does not kill the cells. However, the pores can be used to introduce drugs into the opened cells. This is the basis of electrochemotherapy (ECT), which we also use. It is even more selective and gentler than IRE.
With all electroporation treatments, there is a lower likelihood of side effects than with surgical removal of the prostate, as essential anatomical structures such as the sphincter muscle and the neurovascular bundle responsible for erection are not damaged. With over 1,500 patients treated, including those with advanced tumors, we at VITUS have never caused incontinence, and the impotence rate is below ten per cent.
Leading Medicine Guide: That sounds like a good procedure. In the treatment of breast cancer, for example, the entire breast is no longer removed in most cases these days. Up to what stage can you treat prostate cancer with IRE?
Prof. Dr Michael Stehling: We can use it to treat small carcinomas, but also inoperable T4 tumors that have already spread to surrounding organs. It is precisely because of this broad spectrum of treatment and the fact that we have now successfully treated over 1,500 patients that we are regarded as world leaders in this field. For example, Prof. Mark Emberton from London – one of the world’s leading urologists – regularly refers patients to us who can no longer be treated in London.
IRE is also highly suitable for treating recurrences following radical prostatectomy and radiotherapy. After prior radiotherapy, the tissue is so fragile that further interventions are almost impossible. IRE often serves as a solution here, allowing recurrences within the irradiation field to be treated with virtually no side effects. This also applies to prostate cancer recurrences following brachytherapy or HIFU (High-Intensity Focused Ultrasound) treatment.
Another general advantage of IRE is the fact that it can be repeated as often as necessary. This is not possible with standard treatments for prostate cancer, such as surgical removal of the prostate, radiotherapy and hormone deprivation therapy: each can only be used once.
Leading Medicine Guide: A large part of your work involves providing comprehensive information; you spend one to two hours with each patient. This is because the study results for prostate cancer show that – in short – conventional therapies such as surgery and/or radiotherapy rarely increase life expectancy in cases of low-grade prostate cancer, and, according to the available statistics, do not increase it in many men with aggressive cancers either. At the same time, conventional treatments have serious side effects such as erectile dysfunction, impotence and incontinence.
Prof. Dr Michael Stehling: In my view, a great deal of public education is needed here. Prostate cancer is enormously complex. And unfortunately, I find time and again that even the medical profession at large often has little understanding of it, let alone of medical advances in diagnostic and treatment methods.
These problems mean that most patients are either inadequately or incorrectly informed about prostate cancer. Some are in a panic because they have been told that, following a diagnosis of prostate cancer, the prostate must be removed immediately and without delay to prevent metastases and death. That is, of course, complete nonsense. Prostate cancer develops extremely slowly. Most men carry prostate cancer around with them for five to ten years before it is detected. The most important advice for men diagnosed with prostate cancer is: you have time to inform yourself thoroughly, usually months. In fact, most men with prostate cancer die of a heart attack, stroke or other cancers – but not from their prostate cancer! And for men with low-grade cancer, treatment is usually not necessary at all. The probability of dying from a Gleason 6 carcinoma within the next fifteen years is less than one per cent!
So there is a great deal for those affected to learn and decide. This should not be rushed. And alongside methods such as IRE, there are now a range of advanced therapeutic procedures, such as photodynamic therapy, lutetium-177 radioligand therapy or CyberKnife radiation (not to be confused with NanoKnife®), as well as immunotherapeutic approaches, which, depending on the situation, enable effective and gentle treatment. In most cases, however, patients must pay for these newer therapies themselves. Private health insurers, for example, are only slowly beginning to cover IRE treatment.
Leading Medicine Guide: So, with the VITUS Prostate Center and the VITUS Private Clinic, you can practice the kind of medicine that is close to your heart.
Prof. Dr Michael Stehling: Exactly, I want to practice good medicine. To do that, you have to be professional and always keep up to date with the latest scientific developments. But you also have to be responsive to the patient, taking into account their level of understanding, their worries and concerns. And then you have to do what is best for the patient, develop the right treatment plan for them and treat them using the best possible methods.
We would like to express our sincere thanks for these highly interesting insights into such an important field of medicine – and for the glimpse into the innovative solutions that modern high-performance medicine already offers us today. Anyone wishing to contact Prof. Dr. med. Dr. phil. Dr. med. habil. Michael K. Stehling directly can do so very easily via his profile page in the Leading Medicine Guide.
