Q&A with Dr. Byron Hodge on cryotherapy
Central Florida Health News (CFHN): How long has cryotherapy been a treatment option for prostate cancer?
Dr. Hodge: Cryotherapy or freezing has been around for many years as a treatment for disease, but as far as contemporary prostate cancer, probably in the early 1990s was when there was a new interest in freezing the prostate. This was done under ultrasound guidance with an ultrasound probe in the rectum under real-time ultrasound with needles placed through the patient’s perineum directly into the prostate.
CFHN: How has modern technology changed the procedure?
Dr. Hodge: The difference is a freeze that took me four to five hours in 1990 is now about an hour and 30 minute procedure.
CFHN: How does the cryotherapy work with prostate cancer?
Dr. Hodge: There is a lot of research in cryobiology, because you can freeze something and kill it or you can freeze something and preserve it. When we do the freezing on the prostate, we freeze it and then we warm it up quickly, which thaws it. We freeze it and then thaw it again. That process disrupts the prostate tissue and the second freeze disrupts the prostate cells, causing them to break. That dead prostate tissue is then liquified and reabsorbed by the body. The little shell is left behind.
We have a special warming catheter I put in the urethra to keep it warm, so the urethra isn’t frozen. That way most patients are urinating fairly normal within five days after the procedure, and usually a month after it they are urinating normally.
CFHN: Tell me about the side effects of cryotherapy.
Dr. Hodge: One of the downsides with freezing is if you freeze the entire prostate, by definition you will freeze the edges of it and the chance of impotence is about 80 percent. It’s pretty high, but with the local freeze or the focal freezes, we really spare those areas and the chance of impotence is probably closer to 10 percent. It’s pretty low.
CFHN: Why would someone choose cryotherapy over other treatment options?
Dr. Hodge: This is the primary treatment for people who had radiation therapy and the radiation therapy didn’t work. The cancer came back locally. One of the reasons for freezing people is called radiation failures.
CFHN: Would there be increased instance of side effects if a person had a second freezing?
Dr. Hodge: Depends on where you have to have the freezing. If freezing closer to the sphincter muscles then there’s a higher instance of incontinence or mild dysfunction. If it’s a focal area, you re-biopsy the patient and you find two areas out of 12 that have cancer, then usually there are no increased instances of side effects. It’s very easy to do.
CFHN: Could a person have cryotherapy a third time?
Dr. Hodge: You could have a third time, I’ve probably done a third freeze on half a dozen patients in 15 years. The problem is that when the cancer recurs like that, it recurs and the cancer is already outside of the prostate, so it’s no longer localized. With the new technology being so precise, a third freeze would be a very, very rare thing.
CFHN: Was the early cryotherapy different from the technology used today?
Dr. Hodge: This was “garage medicine,” because at the time there was only one company that had probes, and the probes were large, and we had to make our own sheaths to put them in, and we had to make our own warming devices, I mean this was really a leap of faith to be doing this, and it worked well, but it was cumbersome and it took a long time, and there were a fair number of complications, because with the old equipment, when you turned it off, it kept freezing for two or three minutes and then we’d have problems with freezing the rectum and getting holes in the rectum and stuff like that.
CFHN: Tell me about the modern technology.
Dr. Hodge: Through the 1990s and early 2000s, there have been significant improvements in the equipment we use. The most common equipment we use is from a company called Galil, and they make cryotherapy equipment. Back then, the only machine was the size of a bookcase and it used three huge tanks of liquid nitrogen. The machine we use today is about the size of a roller table and weighs about 100 pounds.
The needles are very small 17 gauge needles so we don’t need special sheaths to put them in with and they cool extremely quickly so when you turn them off they stop freezing immediately. So, it’s the difference between flying a huge jumbo jet and F-37 fighter. The needles create very predictable zones of freezing and we overlap those zones to freeze the prostate. We can actually sculpt the ice in the prostate to freeze what we want to freeze.
In addition, I have these multi-gated temperature probes that are like meat thermometers. I put one along the rectal wall one along the nerve bundles and one along the sphincter area and I can measure the temperatures at any given time, so not only can I see the ice forming, but I can measure the temperatures so I know it is a cold enough temperature to kill the cancer, and know that I haven’t gotten it too cold on sensitive areas like the sphincter muscle and nerves.