Tuesday, July 10, 2018

Edith Quimby - pioneering medical physicist

In the early decades of the 20th century scientists around the world were busy looking for ways to use radioactive materials. Following its groundbreaking discovery by Marie and Pierre Curie in 1898, and then the isolation of radium as a pure metal by Marie Curie and André-Louis Debierne in 1910, radium seemed to hold the most promise. The two most common applications were in luminescent paint applied to clock hands so they glowed in the dark, and in medicine where it was used to treat cancer.

We know from learning the story of the Radium Girls, using radium as a component of paint would have deadly repercussions. By the mid-1920s, countless young woman had died after working painting on the dials of watches and clocks. They'd been instructed to lick their paintbrushes to create a finer point, and thus they ingested radium in unknown quantities before becoming sick.

The field of nuclear medicine was somewhat more promising. There are some horrific stories of radium being used in large quantities to treat cancers where doctors sewed capsules of radium directly to the tumor, as in the case of Henrietta Lacks and the treatment she received for cervical cancer. But it seemed that smaller doses had some positive effects. The question was how much was the right amount?

That answer came from medical physicist Edith Quimby. In 1919, after having earned a bachelor's in mathematics and physics, and completed a master's in physics, Edith set out to find a research position. She accepted a position as assistant physicist at the Memorial Hospital in New York City, working with Gioacchino Failla who had established the first laboratory devoted to researching the medical uses of radiation.

It was her task to determine the precise dosage needed for each patient that would have the fewest side effects. At the time, radiotherapy (where radium-containing needles are directly applied to tumors) was in its infancy. There was no consistency in regards to placement or dosage, and no way to determine if the tumor was receiving the correct exposure needed for proper treatment. It was her research that led to a set of guidelines for the most effective arrangement of needles in 1932. Known as the "Quimby rules" they were the standard used until computer-aided placement techniques became available in the 1980s.

She moved to Columbia University in 1942 where she taught radiology and medical physics while conducting research using the new kinds of radioactive materials being created by accelerators and nuclear reactors. She was named as a full professor there in 1954. It was here where she taught future Nobel Laureate Rosalyn Yalow.

Her research also included quantifying the amounts of different kinds of radiation needed to have the same effect, which laid the foundation for future studies to understand how cumulative exposures of each would affect a body. This calculation could not only help inform the doctors about a patient's long-term side effects, but would also help radiation technicians protect their own health by reducing risks of repeated exposure. She created a "film badge" system where X-ray film strips were covered with black paper and distributed to laboratory personnel to measure incidental exposure.

Also in 1954, she became the first woman and first physicist to be named president of the American Radium Society. In her acceptance speech, she outlined the need for an organization of medical physicists in the US. And thus, because of her call to action, the American Association of Physicists in Medicine was founded in 1958.

If you like the work I do here on SRPS, please support me!

For more information:

Her New York Times obituary: "Edith Quimby Dies; Radiation Expert"

Columbia University College of Physicians and Surgeons: "Edith Quimby: First Woman Medical Physicist"

Photo source: Whitman College Archives


Post a Comment