The use of short-lived isotopes in medical diagnosis

This lecture is dedicated to the commemoration of the great British pioneer of radiology, the late Sir James Mackenzie Davidson.

The chosen subject: “Use of short-lived radioisotopes in medical diagnosis” may perhaps appear somewhat strange for this Memorial Lecture, dedicated to Sir James who lived from 1857 to 1919. At the time of his death radionuclides, especially radium, already had a firm place in radiation therapy. But at that time nobody could have imagined that radioactive substances could some day also become important in diagnosis. The prerequisites for this development did not exist until Joliot-Curie had discovered the possibility of producing artificially radioactive nuclides in 1934. The imposing evolution of nuclear physics following this discovery created at the end of the Second World War the technical possibility of producing artificial radioactive isotopes of nearly all elements.

In 1895 the physicist Wilhelm Conrad Röntgen had discovered X rays and only a short time later physicians recognised the extremely valuable diagnostic tool given to them by this discovery. The development in the field of artificially produced radionuclides was quite similar. Immediately after these nuclides had become available medical people realised their versatility for solving diagnostic problems.

At first these radionuclides were used for metabolic studies, applying the tracer technique developed by the Swedish scientist von Hevesy. The need for localising deep lying lesions by differential accumulation of administered radionuclides led Cassen and Mayneord to the development of the first scintillation scanners in 1952.