Chapter 04: Gilbert Fletcher’s Impact on Radiation Therapy


Chapter 04: Gilbert Fletcher’s Impact on Radiation Therapy



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In this chapter, Dr. Almond discusses the advent of cobalt unit F. Hundreds of these units were built around the world, which made radiation oncology much more accessible. Dr. Almond then explains the impact that Gilbert H. Fletcher, an MD Anderson physician, had on developing a unique and aggressive—although controversial—treatment regimen.



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The Making Cancer History® Voices Oral History Collection, The University of Texas MD Anderson Cancer Center


Houston, Texas

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The University of Texas MD Anderson Cancer Center - Overview; Portraits; Overview; Definitions, Explanations, Translations; MD Anderson History; MD Anderson Snapshot; Understanding Cancer, the History of Science, Cancer Research; The History of Health Care, Patient Care; Technology and R&D; The MD Anderson Brand, Reputation; Patients; Patients, Treatment, Survivors; MD Anderson Impact; MD Anderson Impact

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Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.


History of Science, Technology, and Medicine | Oncology | Oral History


Peter Almond, Ph.D.

Then the next generation of the cobalt unit was the cobalt unit F, and people used to say the F stood for Fletcher. Whether it did or not, I don’t know, but that’s the next generation of it, which rotated around the patient, which was all the way around the patient, which allowed you to . . .

Stups were easier and you could do rotational treatments and things like that. Fletcher had a lot to do with that unit, and it was un use here for a long time. But it really made fairly inexpensive treatment machines available for anyone.

Certainly, what happened was then they built hundreds of these units and they went in all over the place. Treatments were far superior to the ortho-voltage machines, because there was no skin reaction, very little skin reaction. So it opened up radiation oncology in lots of lots of places, and eventually, of course, where it’s gone to is into developing countries. You go to a lot of Central America, South America, India, places like that, who could afford a cobalt unit or two where they couldn’t afford anything else. So that made that available. Certainly, it was known that part of the development was done here. I think, in terms of the treatment with cobalt units, certainly Fletcher sort of developed a lot of those and got known for that.

James S. Olson, Ph.D.

Do those regimens sort of spread with the machine?

Peter Almond, Ph.D.

Yes. You used to be able to tell an Anderson trained radiation oncologist by how they treated patients, because it was the way Fletcher would treat. And there would be the people from Stanford [University] and there was the Stanford treatments. And Stanford never went with

cobalt units. They always stuck with linear accelerators. They had one form of treatment. And there was the Memorial treatment. Very much the approach to treatment became—

James S. Olson, Ph.D.

What was the Memorial treatment?

Peter Almond, Ph.D.

Oh, I don’t know. It was certainly probably different fractionations, different dose levels, and that type of thing that got developed.

But certainly, I think the development of the cobalt 60 was Fletcher’s. But at the same time, because by the time we got the cobalt here was when this building opened, the original building, of course, was opened. They moved the cobalt unit in shortly thereafter, and the Betatron, and so Fletcher was doing both at the same time.

James S. Olson, Ph.D.

This is in ’54?

Peter Almond, Ph.D.

This is in the late fifties. They started in ’54. I think he sort of developed both treatments, and in many ways his treatment with the high-energy X-rays got him a lot of notoriety, because not many people had that energy and he was really advocating it. When we got the first linear accelerator, his instructions to me were produce the beam from that Betatron on the new linear accelerator. That’s essentially when he said. He said, “I’ve got this beam out of the Betatron. I want the same beam out of the linear accelerator. Make sure I get it.” So that’s what we had to do. We had to work with the manufacturer, and we matched the betans for it. That’s what he wanted.

Again, then, in the seventies, it became a fairly well publicized sort of controversy between Anderson and a lot of other places, because Fletcher was saying you’ve got to have at least twenty-million electron volt X-rays, and there were a lot of people using ten to fifteen MEV, and he just said that’s not high enough. He got into some pretty good arguments with manufacturers and other people about what was the right energy to use. That’s disappeared today because of this intensity modulated radiation therapy. You can do those with six MEV X-rays. You don’t need the high-energy X-rays anymore. So we’ve sort of passed through the cobalt era into the linear accelerators and Betatrons and then the very high-energies. That era has just about disappeared because of the techniques that have made them obsolete, how you can use lower- energy machines to do, and there are certain advantages of using lower-energy X-rays.

When you produce very high-energies, about fifteen MEV X-rays, and the old Betatron and the linear accelerators were about that energy, you produced neutrons, and they’re not particularly

nice to have around. They take a lot of shielding and also some danger for patients to get whole- body neutron doses, so we’ve always worried about that here.

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Chapter 04: Gilbert Fletcher’s Impact on Radiation Therapy