First, what is medical physics? That is important because it will matter for the rest of this. Medical Physics is really the science of where medicine and physics meet. The biggest area of overlap is in radiation (x-ray equipment, CT, Nuclear Medicine, Radiation Therapy), but it also includes magnetism (MRI), sound (Ultrasound), temperature (thermal ablation and cryotherapy), optics, transmit/receive coils, and all sorts of other areas. Medical Physics really began when the equipment became out of hand for physicians to keep up with. In all honesty the radiologist really doesn’t need to know which filter to put in place on a mobile x-ray unit in order to generate optimal images. All the Radiologist needs is the image. Your oncologist doesn’t need to know anything about gradient fields when looking for tumors in the brain. As hospitals grew larger and had more equipment, equipment that was more specialized, and equipment that could be optimized per patient it became somewhat critical to have a generalist on hand who knew the fundamentals of the equipment. The hospitals would often hire someone with a M.S. or (more rarely) PhD in Physics. These were called Medical Physicists. It turned out it was difficult to train the physicists so the ABR developed a test to determine whether someone calling themselves a Medical Physics actually knew the breadth of physics associated with medicine.
After a while a few schools developed programs specifically designed to teach Medical Physics. CAMPEP worked on an accreditation program so that aspiring Medical Physicists could know whether the program they were applying to was any good. Anyone with a physics degree can study Medical Physics and become a certified as a Medical Physicist. If you want to go directly into the field you can study at a school and have a better chance of passing the exam, and the CAMPEP accreditation program verifies certain programs are good. However, in the late 2000’s the ABR updated their guidelines so that everyone wanting to take the certification exam after 2008 would have to have graduated from a CAMPEP accredited program. The guidelines were further updated so that after 2013 candidates would have to have gone through a CAMPEP accredited residency program, or have 36 months experience under a board certified Medical Physicist (that pathway will close in 2024). So over the course of 2 decades Medical Physics will have gone from “have an advanced degree and demonstrate a knowledge of physics as applied to medicine” to “complete a CAMPEP accredited program followed by a CAMPEP accredited residency.” Also, to “help” potential Medical Physicists who already hold an advanced degree in physics meet the requirements a new certificate pathway has been opened. This certificate is effectively a post-doc program, and still requires the residency afterwards. Notice this “new” program is actually a barrier between the PhD in Physics and ABR certification that did not exist 10 years ago.
So the time to become a medical physicist has grown from 2 years (M.S. in Physics) to typically 7 (5 years in a PhD program followed by a 2 year residency). Yes, the M.S. is a possibility, but landing the required residency without a Doctorate is nearly impossible. Now we should ask, “So an extra 5 years, there must have been a really big problem that the training needed to nearly triple. What was that problem?” It is difficult to nail this down. You will get squishy answers like “equipment is so much more complicated now and the tasks bigger,” but not really. By the mid 2000’s (back when a M.S. in physics could directly take the exam) we already had x-rays, mammograms, CT scanners, MRIs, PET, SPECT, Gamma Cameras, Linear Accelerators, Ultrasound, Brachytherapy units, Cobalt radiation units, and so on. Radiation safeguards had been put in place, and the means of testing and calibrating equipment had become standardized. Additionally equipment manufacturers have been continuously trying to improve their equipment with auto-calibration and other techniques that lowers the impact of Medical Physicsts and makes their jobs easier.
On to personal speculation… Medical Physicists were also being paid quite well in the 2000’s and many new physicists were entering the field. If the barrier to entry remained low wages were likely to stagnate. Barriers reduce competition so that only those willing to get their B.S. in physics and commit to an additional 7 years would become Medical Physicists. The images to radiologists do not become better for the extra 5 years, therapeutic equipment is no less likely to fatally overdose patients, brachytherapy units are no less likely to overexpose patients, and MR scanners are no less likely to produce imaging artifacts due to the extra training. However, the wages of the Board Certified Medical Physicists (you know, the ones at ABR helping to guide standards for certification) remain artificially elevated. I don’t know how it panned out but near the end of my program I know there was a push to have insurance companies require hospitals to have a staff Medical Physicist in order to be fully reimbursed for diagnostic radiology. Again, a new regulatory burden in the guise of ensuring patients get the best care, but really just forces hospitals to hire an expensive physicist they don’t really need. Honestly this protectionism sickened me to the point where I didn’t even want to bother with the certification and decided to go into industry after earning my PhD.
What does this have to do with anything? The salary for a Medical Physicist has been growing faster than inflation (just like everywhere else in healthcare). The same games are played with Radiologists. A while back my friend’s son hurt his arm and went in for an x-ray. The doctor said he thought it might be broken but would have to wait for the radiologist to read the image on Monday. It is highly unlikely the Radiologist said anything on Monday that the primary care physician didn’t already know. However, between insurance, licensing, and regulatory protections it is just plain safer for the GP to have a radiologist read to see if there is a hairline fracture. All the docs on this site know that they would be able to tell if there was a fracture, and if they couldn’t actually see one they would probably advise using a sling for a few weeks. This is something a GP most certainly is competent to do, and was the way the industry operated for decades. Honestly if you are unsure on the current equipment you sure wouldn’t have seen anything on an old (circa 2000) film. The radiologist read provides no value but is required for some unknown reason buried deep within regulations and reimbursement. This plays itself out through the whole industry. If the professional is board certified they are overpaid, the process of certification by nature artificially raises prices. If you can pass a competency exam you are competent, you do not need to demonstrate competency and go to 10 years of training. The 10 years may be required, but if someone else can demonstrate competency after 5 years they shouldn’t need 10 just to meet a requirement. The opacity of the arrangements (you only get fully reimbursed for a CT scan if it is done in a hospital facility with a staff physicist and read by a radiologist) is mind-numbingly stupid from an outsider’s perspective, but makes perfect sense for rent seeking.
There is a new AI algorithm that outperforms most cardiologists in detecting heart murmurs. What do you want to bet that PAs will be prohibited from signing off on the results from a piece of equipment that is more accurate than the cardiologist down the street? Because cardiologists are awesome and nobody better step into my space or reduce my reimbursements! What, you have a little box that can do what I do? Well, I better get paid every time you use it. We can set that up by allowing you to use the box, but only if you are overseen by a cardiologist, and then we will keep the reimbursements the same because I will perform the critical task of “interpreting” the clear concise information on the screen in front of you. For a GP they can send over a copy of the results and I will consult. Also, let’s make sure that insurance protections cover cardiologists who miss a murmur but not general practitioners. Crap like that is all over the place in the healthcare industry, buried in contracts, reimbursement codes, and tort law.