Harper, 89, had developed diagnostic tools in radiology

Paul Harper, a pioneer in the diagnostic and therapeutic uses of radiation and the development and testing of radiotracers in the early days of nuclear medicine, died Friday, July 15. He was 89.

Harper, Professor Emeritus in Surgery and Radiology, was the key member of a University research team, which included Katherine Lathrop, Don Charleston and Robert Beck, that was one of the first to investigate several of the tools of modern nuclear medicine.

They are perhaps best known for introducing technetium-99m into clinical practice in the early 1960s as a radiotracer agent. This substance is now used about 35,000 times a day in the United States and 20 million times a year worldwide in nuclear medicine scans designed to identify tumors or abnormal physiologic processes.

Harper and Lathrop also developed the commercial method for producing iodine-125, another commonly used diagnostic radionuclide. Harper and colleagues were among the first to investigate the medical applications of dozens of radioactive isotopes, including the use of thallium to assess the heart muscle—another test in common use today.

They also were leaders in the use of various types of radioactive implants to deliver a therapeutic dose to tumors. This form of treatment has become routine for prostate cancer, but Harper found ways to apply it to many other sites throughout the body, including the pancreas and the brain.

“Paul Harper was insatiably curious and intellectually fearless,” recalled Beck, Professor Emeritus in Radiology. “Although he trained as a surgeon, he was willing and able to learn whatever he needed, whether it was math, physics, chemistry, nuclear physics, dosimetry, anything that would help him attack the problem. And almost daily he thought up new problems, new things that needed to be done. For sheer imagination and creativity, there aren’t many like him.”

Born July 27, 1915, in Chicago, Paul Vincent Harper was the grandson of William Rainey Harper, the founder and first president of the University. To gain some distance from that legacy, he attended Harvard University where he majored in biochemical sciences and graduated in 1939. Harper completed Harvard Medical School in 1941 and then began a surgical residency at Chicago. He served in the Army from 1942 to 1945, then returned to Chicago, where he completed his residency in 1951. He also was an instructor at the University from 1949 to 1953.

Harper was promoted to Assistant Professor in Surgery in 1953, Associate Professor in 1955, and Professor in 1960. From 1963 to 1967, he served as Assistant Director of the Argonne Cancer Research Hospital, an Atomic Energy Commission facility that opened in 1953 on Chicago’s campus. In 1972, Harper became a Professor in Radiology, as well. Although he retired in 1986, he remained active in research until 2004.

A prolific researcher who shunned administrative tasks, Harper published nearly 200 book chapters and research articles and more than 200 research abstracts. He won several honors, including the Paul Aebersold Award from the Society of Nuclear Medicine, and he founded the American Board of Nuclear Medicine.

In the 1950s, Harper and his colleagues concentrated on therapeutic uses of radiation, inventing techniques to deliver a controlled dose directly to tumors. Around 1960, Harper’s team began to shift their focus toward the diagnostic applications of radiation. They played a major role in the birth of nuclear medicine by developing the first clinical application of technetium 99m, the field’s primary diagnostic agent. Harper and others in the ACRH team performed the first technetium brain scan in 1961, which was “not very good,” recalled Beck. However, it encouraged them to design and build their own brain scanner, which produced a “spectacular” brain scan in 1963.

Although he was known to be painfully shy, Harper earned a reputation, as much among faculty as students, as an inspirational teacher. “He was a born, gifted teacher,” recalled Mullan, “and his preferred podium was the coffee pot in the surgeons’ locker room.”

In 1939, while studying medicine at Harvard, Harper married Phyllis Sweetzer, who graduated from Wellesley College. She died in 1993.

Paul Harper is survived by a sister, Jane Overton of Chicago, and four children: Stephanie, 64, of Glencoe, Ill.; Cynthia, 62, of Chicago; William, 61, of Hartford, Conn.; and David, 58, of Pennington, N.J.; as well as a niece, two nephews and two grandchildren.

A memorial service at the University is being planned for late September.