Computer Technology and Radiation Team Up to Fight Cancer

From an interview with
Dr. T. Rhett Spencer
McLeod Radiation Oncology

Cancer radiosurgery employs radiation to perform cancer surgery without cutting through the skin. McLeod Radiation Oncologist Dr. Rhett Spencer explains the advances that have helped patients live longer with a better quality of life.

Here are the highlights of Dr. Spencer’s comments:
I have been practicing for 33 years and the things that we do today we could not fathom or even dream of back then. So much of it uses computer technology for accuracy and safety. I mean, radiation is radiation. Yet, it is how you deliver it, how you can shape the fields that you are treating, how you can calculate the dose that you are delivering and how we can be so accurate, so focused and pinpoint. These were goals we could not fathom 33 years ago.
 
Radiosurgery comes more into play for brain metastasis, a tumor that has spread from somewhere else in the body. It is primarily for brain metastasis, but it does have some other uses. Instead of having to treat the entire brain, we focus just on the tumor with very little margin around it, very little room. The patient is receiving a very high dose over a short period of time and very few treatments. With radiation, we are destroying that tissue. We must be accurate, because you do not want to destroy the normal tissue around it. We accept less than a half of a millimeter variation in a day-to-day treatment. And that is about the minimum the human eye can detect. And in fact, the machine is probably a lot more accurate than the human eye.
 
The advantage is we are not damaging much normal brain. We are treating very, very little normal brain tissue. The risks of mental impairment, losing mental sharpness, permanent tiredness, hair loss and other general side effects are greatly reduced. The result is a more effective dose with much greater effectiveness.
 
It has changed the entire paradigm of how we treat people with metastatic cancer of the brain. We used to feel that life expectancy with that diagnosis was less than six months. We are now routinely coming back and treating patients with new lesions that have developed that we treated two and three years ago and longer. Some of that is not just a better control in the brain, but that also has to do with better control of their disease elsewhere with immunotherapy, different chemotherapy or combinations of those.
 
Basically, we are taking patients that had a very short life expectancy, and now they are having a very reasonable life expectancy with a good quality of life.

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