Any sufficiently advanced technology is indistinguishable from magic.
Arthur C. Clarke
If I’d asked my customers what they wanted, they would have said a faster horse.
Henry Ford
There is a new kid on the block in Knoxville, perhaps unknown to some. I’m not talking about me because I am a native Knoxvillian and the Doctor Is In column is 14 years old.
Although I write about medical issues less often now than in the past, last week I promised an essay “focused” on medicine, so as Triple H says, “Buckle up.”
Although there is more to the “doctor” than just medicine, my roots are in science. However, in researching this week’s column I need to disclose that I also functioned as an “investigative reporter.” Admittedly, I have no training in journalism and do not claim nor desire such credentials. My opinion of “journalists” has been tainted by the Mainstream Media. Additionally, I am not paid to write. This essay arises from my interest, research and interviews with patients, Knoxville oncologists and radiation specialists, as well as the staff of the Provision Proton center.
Like many of you, I have seen the commercials on TV promoting the Provision center for the treatment of prostate cancer. Admittedly, I am skeptical of advertisements on TV and radio. You may be surprised that I have never been asked by a patient to prescribe a drug advertised on television. Perhaps patients understood my bias.
The ads I saw on TV regarding proton therapy piqued my curiosity. Furthermore, I have had patients and friends with prostate cancer treated with high energy particle radiation instead of conventional X-ray radiation therapy, so I decided to learn more about this newer treatment modality. Actually, proton therapy has been around for decades.
So, I hit the “books,” although these days much medical information is published online rather than in textbooks. Because medical science is advancing so rapidly, the information in textbooks is often outdated by the time a book is published. The Internet is an invaluable tool for doctors and is a treasure trove for the curious, despite the dangers of incorrect information. My chief medical reference for this report is from the highly respected Up to Date medical website.
So, let’s start with the basics, the science of physics – and don’t hold your nose. There are four fundamental forces of nature in the universe. There is gravity, which everyone is well aware of; the strong nuclear force, which bonds protons and neutrons in the atomic nucleus; the weak nuclear force, which governs radioactive particle decay and the release of radiation; and there is electromagnetism, which encompasses the visual spectrum, electricity and magnetism.
Photons are the energy packets/particles/waves of electromagnetism. This spectrum extends from the far infrared (microwaves) to the far ultraviolet (cosmic radiation). We see only within the small visual part of the electromagnetic spectrum. There are other invisible forces around us such as magnetic fields (magnets) or radiation from unstable isotopes of uranium detectable by a Geiger counter. The latter radiation (Chernobyl) can cause cancer or can be used to treat cancer.
If you are still awake and reading, I hope you will learn two things from this essay. First, the Provision Proton center is a jewel in the crown of Knoxville. And second, there is a difference between photons, (energy packets/waves) and protons (subatomic particles within the nucleus of an atom).
Electricity is used to generate photons for medical x-rays. Due to the variable absorption of x-rays in body parts images can be constructed. Bone is dense and absorbs more X-rays than organs like the heart, which is comprised largely of water. The lung filled with air absorbs the least X-radiation allowing more X-rays to expose a photographic plate and produce an image or data points in a computer.
High energy x-rays (photons) can also be generated and directed to destroy cancerous tissue. To limit damage to healthy tissue, the x-radiation beam is rotated while maintaining a focal therapeutic point centered on the tumor. This is the basic mechanism of conventional external beam radiation therapy.
High energy protons are produced from ionized hydrogen gas within a cyclotron. Compared to a photon the positively charged proton is massive and is accelerated within the cyclotron and directed towards the patient’s tumor by a series of magnets. There is less “scatter” radiation with proton therapy because these high energy particles give up their energy in a narrow area called the Bragg peak which can be focused on the tumor with less radiation to healthy tissue. Although this report focuses on prostate cancer therapy, proton radiation can be used to treat many solid tumors.
All radiation damages DNA, but the repair processes of healthy tissue exceed cancerous tissue. This is one reason radiation therapy is usually given five days a week rather than daily. However, radiation oncologists and their staff don’t especially like to work on weekends, but neither did this internist!
In my medical career I have been involved with three academic medical centers and practiced medicine in more than a half dozen hospitals. To supplement my research for this essay I toured the Provision Proton facility. The guy in the mask is me. I have never been in such a high tech, Star Trek-like facility where patients are metaphorically “beamed up” every day. Behind the treatment table are three stories of equipment to support and rotate the treatment gantry fed by the cyclotron 20 meters away. The cost of a proton treatment center is one quarter of $1 billion.
Much has changed in the more than four decades I have practiced medicine. I am not easily impressed and have unfortunately become quite cynical about what has happened to my profession in recent years. However, there are exceptions to every generality and the Provision Proton center is an exception. Never have I experienced such a high tech, professional and yet personal, service-oriented organization. It’s too bad we don’t have the Provision organization and Chick-fil-A running our country.
