Giants in Radiation Oncology: Juan A. del Regato

Juan Angel del Regato, MD
(March 1, 1909 – June 12, 1999)

Growing up in Cuba, Juan del Regato’s father ran the movie projector at a local cinema and was an avid photographer. His familiarity with camera equipment meant he was often called to service the X-ray machines at local physician’s offices. It was on these trips that his young son developed an interest in medicine.

In 1926, Dr. del Regato enrolled at the University of Havana. A few years later, student protests closed the school. He had been working as an X-ray technician and the Cuban League of Cancer offered to send him abroad to finish his medical training at the University of Paris. Although he did not speak Friench, he jumped at the chance.

In Paris, Dr. del Regato attended school and worked in radiology, developing X-rays and assisting with radium treatments at night. The job was exciting but not always safe. On one occasion, a physicist came to Dr. del Regato saying that some radium sources he had been using were not properly sealed. Dr. del Regato, patients and staff had been exposed to massive amounts of radon. Two nurses later developed leukemia and died. “For half a century,” Dr. del Regato told an interviewer in 1984, “I have been expecting to develop bleeding or some other sign of leukemia.”

Dr. del Regato never developed leukemia and finished medical school in 1937. He then accepted a position at the Institut de Curie as assistant to the prominent French radiotherapist Henri Coutard. Coutard was internationally known for his work on fractionated treatments and for curing laryngeal cancer with external radiation when others were still using radium implants. While assisting Coutard, Dr. del Regato was called to X-ray Marie Curie’s arm which she broke after a fall in her laboratory.

Juan del Regato working in a lab at the Institut de Curie, circa 1937.

The open tubes of the treatment machines at Institut de Curie allowed doctors to use reflected light to draw treatment fields on the skin of patients. A British physician approached Dr. del Regato after she learned that her hospital had bought a machine with enclosed shockproof tubes that did not emit light. Dr. del Regato designed an add-on localizer capable of reproducing the shape of the beam for the physician which she sent back to a British manufacturer. The “del Regato Localizer” was born and quickly incorporated into treatment machines in the United States. The light field remains a standard feature of linear accelerators today.

Gold ultimately led Dr. del Regato to Colorado where he accomplished his most important work. Wealthy businessman Spencer Penrose had amassed a fortune mining for gold outside Colorado Springs. When he developed larynx cancer, he traveled to Paris to consult with Coutard. He was so pleased with the results that a few years later, when he developed esophageal cancer, he once again sought Coutard’s opinion. By this time, Coutard and Dr. del Regato had immigrated from France to Chicago.

Mr. Penrose began his treatment in Chicago but hated the oppressive Midwestern heat. He paid General Electric Co. to install a treatment machine at his home in Colorado Springs and insisted that Coutard come out to supervise his care. After his treatments were completed, Mr. Penrose and his wife donated the machine and significant funds to a local facility, the Glockner Tuberculosis Hospital, which in 1939 was renamed the Penrose Tumor Institute, and later, the Penrose Cancer Hospital.

Despite a population of less than 50,000, the Penrose Cancer Hospital in Colorado Springs had an “excessive amount of equipment” including 3-200 kV units, 1-400 kV unit and a substantial amount of radium. Patients came from all over the country to be treated at Penrose and in 1949, Dr. del Regato became the center’s director.

Hoping to permanently establish therapy as an independent specialty, Dr. del Regato created one of the first and largest training programs in the U.S. for radiotherapists (the operative nomenclature at that time). At a time when radiation therapy was a subset of General Radiology, Dr. del Regato petitioned the American Board of Radiology to separate the training, exam and certification processes. Penrose graduates include James Cox, Larry Kun, Robert Bogardus, J. Frank Wilson, Jerome Vaeth, Robert Lindberg, and many others from around the world. While at Penrose, Dr. del Regato debunked the widely held belief that adenocarcinomas were “radioresistant.” He treated men with “inoperable” prostate cancer and proved for the first time that prostate cancer could be cured with radiation. In 1947, with Lauren Ackerman, MD, a renowned pathologist at Washington University School of Medicine, he co-authored the first edition of Cancer, which for decades served as the authoritative textbook of cancer biology, diagnosis and management.

In 1955, the first meeting of the American Club of Therapeutic Radiologists was held at the Palmer House in Chicago. Organized by Dr. del Regato, the few dozen radiotherapists continued to meet twice a year to exchange ideas and compare notes. Like Dr. del Regato, most were immigrants or had trained overseas. Dr. del Regato memorably interrupted a presenter at one of the meetings who, like himself, spoke with a strong accent. He asked the man what language he was speaking. I am speaking the international language of radiotherapy, the man replied, Broken English. As the number of radiotherapists grew, the organization name was changed to the American Society of Therapeutic Radiology (ASTR) in 1965, a precursor to today’s ASTRO. In 1977, ASTR awarded its first Gold Medals to Dr. del Regato, Gilbert Fletcher, MD, and Henry Kaplan, MD.

At the end of his career, Dr. del Regato retired to Tampa, Florida, where he continued to teach and care for patients at the Veteran’s Administration Hospital. He also published biographies in the Red Journal on significant physicists including Wilhelm Roentgen, Max Planck, Niels Bohr, and others. Dr. Juan del Regato died in 1999 at the age of 90, his wife, Inez, having predeceased him. He was survived by two daughters, a son, and five grandchildren.

Dr. del Regato’s dedication to our field lives on in the Radiation Oncology Institute’s Juan A. del Regato Fund. Like its namesake, the fund, administered through the ROI, supports efforts to foster innovation, education and community amongst young radiation oncologists as well as preserve the history of our specialty. The life of Juan del Regato reminds us to never stop looking for better ways to deliver safe treatment, commit to educating a new generation of leaders in our field and welcome diverse voices to our table.