Lester S. Skaggs

Abstract

Medical physics lost one of its innovators when Lester S. Skaggs died of natural causes on 3 April 2009 in Chicago. Skaggs made seminal contributions to the application of radiation to cancer treatment and the development of its technology and instrumentation.Skaggs, who was born on 21 November 1911, was raised on a farm in northern Missouri. He went to a one-room country elementary school and made the three-mile trek to high school on a pony. He studied at the University of Missouri and received a BS in chemistry with a minor in mathematics in 1933 and an MS in physics in 1934. At the University of Chicago he worked under Samuel Allison on the precise determination of the energy released in the production of deuterium from proton bombardment of beryllium, which earned him a PhD in 1939.Skaggs spent the following two years as a postdoctoral fellow in nuclear physics at the University of Chicago. At the same time, he held a part-time job at the nearby Michael Reese Hospital. The radiation oncologist there was interested in acquiring a betatron, recently invented by Donald Kerst, to extract an electron beam and use it to treat cancer. However, because of World War II, the project did not get off the ground. Instead, Skaggs was drafted to work at the department of terrestrial magnetism of the Carnegie Institution of Washington and developed an antiaircraft detection system. After moving to the Manhattan Project in 1943, he transformed his system into a fuse to detonate the first atomic bomb. He created a radar-based proximity device with two backup systems. After the first test at Alamogordo, New Mexico, he decided to delay the time of detonation by an additional 30 seconds to ensure that the aircraft would reach a safe distance.At the end of the war, Skaggs was still interested in the possible use of electrons for cancer therapy. He was hired by the Michael Reese Hospital and sent to work with Kerst at the University of Illinois in Urbana, where they succeeded in extracting the 22-MeV electron beam from the betatron. Soon after, he and several other scientists developed a radiation-treatment technique to use on a physics graduate student who had been diagnosed with an inoperable brain tumor. It was the first such treatment that used electrons.In 1946 Congress passed the Atomic Energy Act, which provided for the creation of the Argonne Cancer Research Hospital at the University of Chicago. Skaggs took a position with the university in 1948 and led the development of the radiation therapy facility at the ACRH, which was completed in 1953. With Lawrence Lanzl, Skaggs designed, built, and calibrated a 2000-curie cobalt-60 rotating treatment unit, the first in the US. Skaggs arranged for a 5- to 50-MeV linear accelerator, developed at Stanford University, to be installed at the ACRH. To obtain multiple electron beams aimed at the tumor from different angles without moving the patient, he contracted with Varian Co in California to build a rotating gantry. The electron beam was 12 cm in diameter mechanically scanned over a custom-shaped irregular field. The design, construction, and calibration of the project cost $450 000. First used to treat a patient in 1959, the linac was in clinical use for 34 years.To foster the growth of medical physics, Skaggs started a graduate training program at the master’s level in the mid-1950s, expanded it to the doctoral level in the 1960s, and added postdoctoral training in the 1970s. He directed the program until 1979.In the mid-1960s the ACRH got funding for a small cyclotron to produce short-lived isotopes for diagnostic research. Contemporarily, at the Hammersmith Hospital in London, cyclotron-produced neutrons from the Be(d,n) reaction were being tested as a possible cancer treatment tool. In the early 1970s, after I joined Skaggs’s group, we developed a high-pressure cryogenic deuterium-gas target used for the D(d,n) reaction to produce a neutron therapy beam; it was the first hospital-based neutron therapy facility in the US. After leaving the University of Chicago, Skaggs spent five years at the King Faisal Specialist Hospital in Saudi Arabia, where he installed a commercial cyclotron-based neutron therapy facility and established a dosimetry calibration laboratory. He returned to the university and continued as a professor emeritus in the department of radiation and cellular oncology until his death.Skaggs was a natural teacher and a true gentleman who graciously shared his wisdom, common sense, and deep knowledge of medical physics. His students, colleagues, and friends deeply miss his guidance and generosity.Lester S. SkaggsPPT|High resolution© 2010 American Institute of Physics.