Welcome to the Sprechstunde. I am delighted that you have tuned in today. Today, we are visiting the European Radiosurgery Center Munich where benign and malignant tumors are treated and destroyed with high-precision technology. In today's Sprechstunde, we will show you exactly how this works and what the treatment looks like.

Professor Muacevic, we are at the European Radiosurgery Center Munich, as it is now called. Many people still know it as the CyberKnife Center Munich Großhadern. How did this change come about?

Yes, we needed a new name because of the new technology that we will take a closer look at later. The old name no longer fits, which is why we, and our cooperation partners, have agreed on this new name: European Radiosurgery Center Munich. Now, we are well-positioned for the future.

In today’s Sprechstunde, we want to shed light on some medical innovations. What do you consider to be innovative medicine? And what does that mean to you?

Innovation always comes with improvements for the patient, e.g., less stressful or shorter therapies. Or, perhaps, therapies which allow us to treat patients successfully without prescribing them additional drugs – as was the case not so long ago. Hence, anything that benefits the patient. And there are a lot of medical innovations taking place, but – and this is somewhat problematic – only a few of them are known to the public.

Many of our patients get to know us by chance. They might have heard about us from their neighbor. That is to say, it is not easy to spread the word about medical innovations, so that everyone who might need them can benefit.

What exactly happens during CyberKnife radiosurgery? How can we imagine that?

A lot has changed in the last 16 years. With regards to our most common type of treatment, the robot-aided radiosurgery, we have now established the third system. The general idea of this cutting-edge technology is to replace serious surgical interventions, with non-invasive and, in most cases, single-session treatments. To me, that is modern medicine for the benefit of the patient.

Plus, we have become very well established over the past years: More than 10,000 patients have been successfully treated at ERCM. And we will advance further. In the beginning, we could only treat brain tumors. Then we went from being able to treat tumors in the spine to even more areas, such as the lung, the liver, and the kidneys. And in the last two to three years prostate tumors have become a new focus of ours.

If you look back on the many years of treating patients, were there times when you asked yourself, “Is this the right technology to use – before it is fully established?”

That's a great question. However, even 16 years ago, robot-aided, image-guided radiosurgery was well ahead of its time. And it still is very, very good. Its precision is unmatched. The accuracy is less than one millimeter, usually about 0.5 millimeters. That is wafer thin – you can barely see it with your eyes.

Being able to work with this kind of precision is a real advantage. It allows us to keep patients’ treatment times and intervals short. In the past, patients would usually have to come in for multiple sessions. Nowadays, most patients only need a single session because of this extremely precise technology.

What I find so special about this technology is that it takes away the patients’ fear. When you hear the word 'surgery', most of us would think of scalpels and cuts and blood. But not so here.

Right! The technology we use is non-invasive. CyberKnife never comes closer than 80 centimeters to the target structure. Neither conventional surgery nor anesthesia are required for this type of therapy. In fact, most patients can return to their home just five minutes after the session.

They come back for the first follow-up examination after three to six months, depending on the indication. Based on the imaging, we can examine the initial result.

I assume it is important that the human being, the physician, is still an intermediate between the robot and the patient? So that a human being is still supervising the treatment.

That is extremely important, of course. That is why we take a lot of time for our patients – especially during the initial consultation, for which we schedule at least half an hour. Of course, no one just lies down under a robot. We are not an assembly line. We explain the entire procedure to our patients in detail. As a patient, you must understand what is going on. How does it work? How exactly do the rays eliminate the tumor? We discuss this in great detail and thus our patients’ acceptance of it is very high.

You treat both benign and malignant tumors with the help of these innovative technologies. Where in the body can these be located?

They are very different types of tumors. Brain tumors are usually benign. However, to mention a malignant type, we also treat cerebral metastases. Within the rest of the body, they are mostly malignant, e.g., lung carcinomas or kidney tumors. Although, and I must point this out, these cases are – unfortunately – rarely suitable for our technology, because these malignant tumors often tend to spread.

If there are too many affected areas, especially with lymph node metastases, local therapy is not useful. But if there is an isolated tumor of about two centimeters, which would usually be removed with conventional surgery, our non-invasive therapy may be a good alternative.

We have talked a lot about these medical innovations. Now, let us take a closer look. Shall we?

Professor Muacevic, we have already learned a lot about the European Radiosurgery Center Munich, as it is now called. We have now arrived in a very futuristic room, the so-called ZAP X. And we have also brought reinforcements: Dr. Christoph Fürweger is here with us. He is part of the team here at the ERCM. What kind of machine is this, the ZAP X?

We are proud and excited that we have been able to establish ZAP X here in Munich. This is only the sixth of its kind worldwide and it has been designed for high-precision radiosurgery of brain tumors. It was conceived by Professor John Adler from Stanford University, who also invented the CyberKnife system. History is being continued, one could say. Once again, we are working together with the Klinik Großhadern and the AOK Bayern to realize this project.

How does ZAP X transform Munich and Bavaria into a center of medicine?

Being able to conduct the most innovative therapies is something we always appreciate – and so do our patients. ZAP X offers even more possibilities, going beyond the CyberKnife. It allows us to treat brain tumors with even more precision. Hence, it is of great advantage for the area and for Bavaria.

How do these two technologies, i.e., CyberKnife and ZAP X, complement each other at ERCM?

The ZAP X is a great addition to our existing CyberKnife system, because we have reached our capacity limits. 50 to 60 percent of our patients have neurological indications, i.e., essentially, brain tumors. And we are looking forward to treating more and more of them with ZAP X. This allows us to conduct more complex treatments, of moving organs, lung tumors, kidney tumors or even prostate cancer, with the CyberKnife.

Being diagnosed with a tumor most often comes as a shock to patients. How do you deal with the fear that, as I imagine, many patients face when lying down in such a device?

It is a difficult situation to deal with, of course. ZAP X has a great advantage for the patient: It allows the operating personnel to stay in the room. That already takes away the fear of many patients, because they are not alone, they are not separated from their physicians. We do not just see the patient through cameras. We are close by, right there with them. And ZAP X is also a bit more spacious compared to an MRI, for example. In fact, it is quite comfortable. I have tried it myself.

ZAP X is about 1.20 meters wide, so it is less cramped than an MRI. Plus, patients can look out sideways which is an advantage for the mind. It is not necessarily the most relaxing position, but it is perfectly fine for a short treatment.

We just conducted three ZAP X treatments last week, each taking less than 15 minutes. Imagine that! A one-time tumor therapy in less than 15 minutes. As an alternative to conventional surgery, that is something special. It puts us right at the forefront.

To add to that, we try to make the session as comfortable as possible for patients. Before we start, we take our time to explain the procedure in detail. Patients can interrupt the session to take a break at any time. We can even play their favorite music to make the treatment as comfortable as possible.

What are the specific steps – from the first consultation to the radiosurgery itself?

First and foremost, imaging is crucial. We need an MRI scan or a CT scan or, sometimes, a PET/CT. The imaging must be carried out in advance so that we can properly identify the tumor. Then, we conduct an in-depth analysis and create a treatment plan, which – in many cases – is much more complex than the actual therapy.

Most of the time, patients only spend a short time here. Simply because they are not around for all the preparations we make beforehand, but only for the actual treatment. As I mentioned, in an ideal case, the whole thing only takes about 15 minutes, but the planning we do in advance can easily take one or two days – especially for more complex tumors. That is our main task. Once we complete the treatment plan, the patient simply lies down, and the treatment takes place fully automated.

Another important part of our job is to decide which device we use for which patient. After more than 15 years, we have plenty of expertise. So, for each individual case, we consider which device is best suited – before the patient even undergoes the imaging process.

To what extent does this technology influence tumor behavior, i.e., tumor shrinkage?

Generally speaking, we closely monitor how tumors behave during aftercare. In many cases, tumors will recede over time. But the extent to which tumors shrink and the time it takes varies significantly based on the type of tumor: Malignant tumors, metastases, for example, usually recede very quickly. We can usually observe the first effects after just three months. Benign tumors can sometimes remain stable for longer and only begin to shrink after six to twelve months.

Every medical innovation offers a vast array of possibilities. But, of course, they also come with limitations. What are the limits of this technology?

Indeed. It is important to talk about these limitations. We have discussed this before: We strictly select our patients. Not out of ill will but because, based on our medical expertise, we must ensure that the cases we take on will be successful. A 90% chance of the treatment achieving the desired outcome is our goal.

And if we cannot make sure that there is a good chance of success, we would rather not carry out the treatment – as it is expensive and takes up a lot of resources. Hence, we use it with the right sense of proportion and in a targeted manner.

But to come back to the topic of radiosurgery and its limitations: It is crucial that the tumors are not too large and that there are not too many. In addition, the patient’s histology, i.e., the fine-scale assessment, is very important.

Just recently, we received several requests for ZAP X from patients, who we could not take on because their type of tumor was, unfortunately, not suitable. We must make these decisions based on our expertise and we are sorry if we must disappoint patients. But this way we can make sure that most of the cases we do take on will be successful.

We met Professor John Adler here in Munich when he presented this innovation. How does it feel to collaborate with such an impressive character?

He is fascinating. He invented the CyberKnife from scratch and turned its success into a globally operating company. He plans on doing the same with ZAP X to further establish radiosurgery worldwide.

CyberKnife is a great device, but it is also very expensive. If you think of poorer countries, perhaps in Africa or South America, CyberKnife cannot be established there – it is simply not viable. ZAP X is more compact and does not require a separate, radiation-proof room. You can basically install it anywhere without major construction work, allowing for worldwide distribution. And that is precisely the idea of this new technology. So, we are delighted that we can contribute to that.

Perhaps, we should mention that, due to our extensive clinical experience, we are the ideal cooperation partner for a company launching a new technology to establish it worldwide. We can contribute clinical experience and make our findings available in publications and studies. So, we do everything we can to further advance this technology.

As I mentioned, we had the opportunity to meet Professor John Adler, who told us about his latest innovation. And here is what he had to say.

I'm happy, I’m excited, I’m worried. This is the inauguration of a new center and that always poses different challenges. But I think this is a great opportunity for the citizens and patients here in Munich. Not only do I believe that the ZAP X can treat many patients in Bavaria and beyond.

ZAP X uses very precise X-rays to destroy tumors and other pathological targets inside the brain. And I liken what the ZAP X does to a magnifying glass. So, if you put your hand directly in the sunlight not so much happens. But if you put a magnifying glass in front of the sun, then all the beams of energy converge in a point, and you have a very effective energy source that can actually now be used to destroy tumors.

And we actually don’t have a magnifying glass, we have this machine that targets all the beams of energy very precisely at the target. And that is how we destroy it without requiring a knife to remove it.

Here we have a CyberKnife treatment plan for a patient with prostate cancer. You can see that here, at the back of the prostate, where the rectum is located, there is a steep drop in the amount of radiation received. Hence, there is almost no dose at all at the front of the bowel. Additionally, above the prostate, up here at the bladder, you can also see a very steep gradient. This highlights the dose is focused precisely on the prostate and does no damage to surrounding organs. Again, the bowel and bladder receive a very low dose.

Currently, we conduct radiosurgery of the prostate in five sessions. The robot automatically tracks and follows the movements of the prostate during treatment. This is the only way we can protect surrounding structures such as the rectum and bladder.

This scan shows one of our first ZAP X patients. He had a malignant melanoma, a metastasis of a malignant melanoma, in the posterior lobe of the skull – quite extensive. What you see around it, these density irregularities, that is all edema, so the tumor was very active. So, we proceeded to treat the patient with ZAP X.

And this is the scan we took three months later: The tumor has receded by more than 90% and the so-called perifocal edema, i.e., the accumulation of water in the tissue, is almost entirely gone. Also, you can see these sulci again, which were no longer visible before.

We achieve this by focusing the dose exactly on the tumor. This way, there is a high therapeutic dose and a steep gradient all around, which protects the surrounding tissue as much as possible. This also allows for the edema to retract.

Let us talk a little bit more about the technicalities. How exactly does the system work?

Once the treatment plan is ready, the patient lies down on this couch – no anesthesia, no fixation. We put a thermoplastic mask on the patient’s face, but this is only a means of support. Then, the patient is placed in the device, where he is constantly being monitored by cameras. In addition, the patient can always communicate with the operating personnel since they are in the same room. When the radiosurgery itself starts, ZAP X moves around the patient to emit fine photon beams from about 100 different angles, thus, taking the tumor into a crossfire.

To ensure that every individual beam hits the target, an X-ray system constantly checks whether the patient has moved. It seems hard to imagine that this compact machine is also equipped with X-rays, but that is how it achieves an accuracy of a tenth of a millimeter. On average, the entire procedure takes 15 minutes. More complex cases may take 20 to 25 minutes, but that is the range we are talking about.

Afterwards, we remove the patient from the machine, and – most often – they do not even feel anything.

I would like to stress that these readjustments differentiate this system from conventional radiation systems, which do not adapt to the patient’s movement. The ZAP X constantly readjusts itself. So, it is not merely a matter of the original position of the tumor or the patient's head. If the patient moves, even slightly, two or three millimeters, the treatment table automatically readjusts before the procedure continues. Thus, we can guarantee a precision of less than one millimeter.

Cooperating with university clinics is an important part of medical innovations. What exactly does that look like for you?

Certainly. This technology is so sophisticated that you cannot or should not just put it anywhere. We cooperate with the university – namely, the Großhadern Clinic – and AOK Bayern, one of Bavaria’s biggest insurance companies. Currently, we have two sponsors: AOK Bayern and the PKV association.

We are still in talks with all the other health insurance providers. But, as a new technology, it is being evaluated and scientifically analyzed in association with our physicists and the corresponding clinical specialists. This allows us to substantiate what we are doing and, more importantly, how we are doing it.

You also have a so-called tumor board. What is it all about?

There are tumor boards for all kinds of diseases. The board scrutinizes individual cases to reach a consensus between experts from different disciplines who then come up with a joint therapy plan. So, it allows different disciplines to come together to find the best possible treatment. One of which could be to carry out a radiosurgical therapy with our ZAP X system.

That is a great advantage of our location: There are many specialists close by. You will not find this very often. If you look at rural areas, it can be difficult to find specialists such as a neurological surgeon, a specialist for tumors, a specialist for vascular lesions, a specialist for pain syndromes. Here, all of them come together on this board, making it much easier to identify the ideal therapy.

Let us take a look at the future: What medical innovations will we see in the coming years that we cannot even imagine today?

I believe that in our field, the field of high-precision radiotherapy, we will see a significant increase in usage. I am convinced that we are just at the beginning of ZAP X’s success story. However, these advances are closely linked to the quality of imaging. The better the imaging, the better the radiosurgery.

There will always be a combination of systemic therapeutic approaches, imaging and high-precision radiotherapy. But of course, we cannot completely write off conventional surgery. That is something we hear a lot: “We won't need that anymore.” But that is not true, of course. There are many cases that still require conventional surgery because many tumors are detected too late. And once they are too large, these machines won’t do much help.

Overall, medicine is constantly evolving. And there are benefits to be found in many different areas, which allow us to treat patients more gently. And that is where we will make a small contribution.

Let me give you a number as an example: With this device, we can generate a beam with a diameter of just four millimeters and target it directly at the tumor. Four millimeters – you can barely see that in the imaging. So, right now it seems like therapeutic methods are evolving faster than diagnostics.

Professor Muacevic, Doctor Fürweger, thank you very much for this exciting chat and the insights into your fields. To our viewers: Thank you for tuning in! That was Sprechstunde for today. See you next time. Stay healthy.