The Neurosurgeon Who Invented CyberKnife 
In an exclusive interview with the prominent John Adler, MD, the Chairman of Neurosurgery at Stanford University and inventor of CyberKnife, he discloses his expert opinion on bioengineering, cancer therapy, and the future of radiosurgery

1.  Did you feel that something was missing from the biomedical community in terms of treatment that inspired you to create cyberknife?

      The cyberknife came out of my deep knowledge of stereotactic radiosurgery. As a neurosurgeon I understood surgery in great detail, and with that knowledge I could see the limitations of the field of surgery as well. In my bones I understood the limitations of our field, and when I first saw the practice of radiosurgery I saw how it could impact the world in which I lived in, the world of surgery. I was fortunate enough to see how radiosurgery could impact the surgical field before the inception and introduction of radiosurgery; I was able to connect the dots between the two fields before the rest of the world could see them.

2. The steps to engineer, produce, test and gain clinical acceptance of these technologies were certainly arduous. What were some of the greatest obstacles you faced in innovating in such an intense field of medicine and how did you overcome these challenges?

       There is no tougher environment in medicine than this arena. It is heavily regulated, and that   means you end up spending a lot of valuable time worrying about the rue book rather than the problem you actually want to fix. I was trying to help patients, that was my overarching goal, yet in order to make that a reality I needed to spend a lot of time dealing with the rules and regulations that were never intended and never envisioned for the world you are trying to make. I understand why we have the rules of the FDA , although some of these rules aren’t there to help patients; nevertheless, I do understand why the FDA needs to go about the cycle of regulations it does. One of the rules that almost killed us was one implemented via the society of robotics. They had very rigid standards which stated that in a setting of a robot, a human being had to be excluded by a 2 meter radius. Yet, my goal was to put the patient right in the face of the robot! So the largest robot manufacturer from Japan was supplying us with our equipment at the time and due to these strict regulations they stopped selling us the robots we needed to innovate in this space. Consequently, we had to rebuild the entire company and ended up using a German robotics manufacturer. Overall, we were dealing with a world of regulations – that of robotics- that was never designed for the world of medicine. And we began infiltrating that arena with the hope to intertwine the worlds of man and robot, and with that came intense rules and regulations we need to overcome to make this a success.

3.       What is the greatest challenge that radiosurgery faces in an age that is booming with technological advancements? Is it competition? Keeping up with the latest technology and incorporating them into your systems?

         Cost and regulatory constrictions! The use of this equipment requires multiple parties to support it; from the hospital administration to the surgeon, everyone in the hospital is involved in radiosurgery on some level, and that is a great challenge. In terms of cost, reimbursement codes from insurance companies is the biggest element we need to address. The issue of cost is that the patients are controlled by the surgeons, but the equipment is controlled by the radiation oncologist.


Picture
John Adler, MD. Inventor of CyberKnife and radiosurgery visionary. 
4.   What is the future of radiosurgery?

      There will be a time when we will definitely see this entire process automated, and this will end up driving down the price of the overall treatment delivered by radiosurgery. The overall effort to treat the patient will go down because certain stages of the process will become automated, and thereby speed up the treatment process. Ironically, if reimbursement doesn’t support that effort than doctors may not actually speed up the process because if people are not paid to make the treatment faster than they simply just won’t do it faster. In the long run, we will be looking at revolutionizing radiosurgery by utilizing high energy laser beams that create a source of x-rays to treat tumors in a high impact and highly compacted manner. From radioisotopes and linear accelerators, we may now be looking at lasers to treat these tumors. The cost of a laser is going down, and these lasers can accelerate electrons and protons in a short distance, which will allow you to use powerful lasers to generate therapeutic x-ray beams which, for example, can exit the end of a catheter in a very minimally invasive manner. The future of radiosurgery will change the way we operate in unimaginable ways. 

5.    Is there a particular type of cancer which radiosurgery will thrive in relative to other cancers? 

   Radiosurgery thought leaders – including myself – strongly believe that radiosurgery will eventually replace all forms for radiation therapy. Whenever possible, we will be using radiosurgery in the most aggressive and localized fashion. The idea of bathing the body in radiation, where there is tumor adjacent to healthy tissue, will be gone. We will hit the tumor, and only the tumor. With the advent of PET imaging, we have the ability to see tumors in a clearer fashion and are able to locate them with ease, which provides a strong platform for the inculcation of radiosurgery in every type of cancer. The key is going to be precision coupled with aggression. We will be able to collapse a 6 week treatment regimen into a 2 time radiosurgery procedure, and we know that surgeons will embrace this if we develop financial incentives as well. 

         In addition, we need to discuss biological manipulations. For 2 decades there has been a discussion of utilizing radiosensitizers, or a variety of other molecules, to increase the efficacy of cancer treatment. The trouble with this is that you still need to give these toxic drugs for 6 weeks, resulting in intolerance and bad side effects. This philosophy just hasn’t worked. The upside of radiosurgery is that we can now give these drugs for only 1 or 2 days, thus limiting toxicity overall. We are looking at attacking the tumor with much more aggression, while simultaneously limiting the toxic side effects of powerful drugs. 

       Lastly, there is a growing belief that the best treatment for cancer is not going to be from cytotoxic drugs, no matter how precisely targeted they become to the tumor ; rather, the forefront of cancer treatment will come from immunology. A growing body of evidence supports the belief that immunological control of tumors is how we will manage cancer in the future, and we are seeing the first generation of these drugs where by blocking an inhibitory pathway in an immune cascade you can get phenomenal immune responses. Therefore, patients riddled with tumors throughout their entire body will have the opportunity to use their own immune system to kill off all the tumors over a period of time. These drugs teach us that the immune system has a miraculous capacity to police cancers. The beauty of radiosurgery as it relates to the immunologic phenomena in cancer treatment is that instead of cutting the tumor out of the patient, we simply kill the tumor and leave it in the patient of the body. Now that the tumor is dead, the immune system can react to that specific tumor in the future, thereby preventing the regeneration and spread of these cancer cells. Therefore, by coupling radiosurgery with the right immune modulators we can develop systemic protection in a patient and prevent the cancer from returning in the future.