From hadron therapy to cosmic rays: a life in biophysics
In 1954 – the year CERN was founded – another scientific journey began at what is now the Lawrence Berkeley National Laboratory. Beams of protons from a particle accelerator were used for the first time by John Lawrence – a doctor and the brother of Ernest Lawrence, the physicist after whom the Berkeley lab is named – to treat patients with cancer. For many years, Eleanor Blakely has been one of the leaders of that journey. She visited CERN last week and spoke with the Bulletin about her life in biophysics.
Use of the cylcotron beam to mimic "shooting stars" seen by astronauts. Black hood on subject Cornelius Tobias keeps out light during neutron irradiation experiment at the 184-inch accelerator. Helping to position Tobias in the beam line are (left to right) John Lyman of Biomedical Division, and Ralph Thomas of Health Physics. (Photo courtesy of Lawrence Berkeley National Laboratory.)Interested in biophysics, which was still a new field at the time, Eleanor joined the staff at Berkeley Lab in 1975. She arrived soon after the Bevatron – the accelerator where the antiproton was discovered – was linked up to the heavy-ion linear accelerator, the SuperHILAC. The combination, known as the Bevalac, could accelerate ions as heavy as uranium to high energies.
Eleanor joined the group led by Cornelius Tobias, whose research included studies related to the effects of cosmic rays on the retina, for which he exposed his own eye to ion beams to confirm his explanation of why astronauts saw unexpected light flashes during space flight. “It was a spectacular beginning, seeing my boss getting his eye irradiated,” Eleanor recalls. For her own work, Cornelius showed her, in effect, a map of the energies and ranges of the different ion beams available at Berkeley. Her job as a biophysicist would be to work out which would be the best beam for cancer therapy. “I had no idea how much work that was going to be,” says Eleanor, “and it’s still not settled!” However, this early work at Berkeley showed the effectiveness of carbon and heavier ions for treating certain kinds of cancer – an important aspect of hadron therapy today.
Bevatron Heavy-Ions Beam Group with Dr. Cornelius Tobias, Dr. Ed McMillan, and Dr. Thomas Budinger studying light flashes in nitrogen beam. (Photo courtesy of Lawrence Berkeley National Laboratory.)Some of the treatments at Berkeley used a beam of helium ions directed through the lens to destroy tumours of the retina. Eleanor was devastated to learn that although the tumour was destroyed, the patients developed cataracts – a late effect of radiation exposure to the lens adjacent to some retinal tumors, requiring lens-replacement surgery. As a result, she not only proposed a more complex technique to irradiate the tumours by directing the beam though the sclera (the tough, white outer layer of the eye) instead of the lens, but also became interested in the effects of radiation on the lens of the eye – a field in which she is now a leading expert.
In 1993, the Bevalac was shut down, leaving Eleanor and her fellow researchers at Berkeley without an accelerator with energies high enough for hadron therapy. However, with her interest in irradiation of the eye, she has been able to follow her first group leader “into space” – at least as a “bench top” scientist – with studies of the effects of low radiation doses for the US space agency, NASA.
Eleanor Blakely’s talk, “Reflections and Perspectives on 60 years of particle therapy” was the first talk in a new seminar series: Accelerating Innovation... in Medicine.
