Remembering the father of radiotherapy


An Irish scientist pioneered the earliest effective radiation treatment for cancer, writes Mary Mulvihill.

For much of the 20th century, doctors around the world treated cancer using a technique pioneered in Ireland. That technique, known as the Dublin method, was the brainchild of John Joly, a brilliant Irish scientist.

Though born in Bracknagh, Co Offaly, John Joly (1857-1933) had an exotic pedigree. His father, the local rector, was of Belgian origin. His mother, a countess, boasted English, German, Italian, Greek and Austrian connections.

Joly was something of a polymath. He studied engineering at Trinity College in Dublin and later joined the physics department, ultimately becoming professor of geology and minerology.

Among other things, he helped to calculate an accurate age of the Earth and to explain how sap rises to the tops of tall trees. He invented several important scientific instruments and an early commercial technique for colour photography, as well as his method for treating cancer.

Medicine's first attempts at using radioactivity to kill cancer, devised shortly after radioactivity was discovered in 1896, were crude. Doctors placed tiny pieces of radium in and around the tumours, a hit-and-miss approach that rarely worked. And because the radium was highly radioactive and very expensive, the technique was also dangerous and costly.

Instead of using radium, Joly thought of collecting the radioactive radon gas (or "emanation") it gave off, then injecting it into tumours. This was more effective, because the radon could percolate throughout the tumour and the dose could be controlled. It was also safer for both doctor and patient, and cheaper, as the original radium source could be used repeatedly.

Joly developed his ideas with Walter Clegg Stevenson, a cancer expert at Dr Steevens' Hospital in Dublin, beginning in 1903. By 1914, they had perfected the Dublin method, which formed the basis for the modern radium needle treatment.

At Joly's suggestion, the Royal Dublin Society established a laboratory to supply radon to cancer units; the initial 200mg radium source was bought for £3,000 with public and RDS funds. The radium service was taken over by St Luke's cancer hospital in Dublin when the Radiological Institute was established there in 1952.

Joly's many other inventions included the differential steam calorimeter, for measuring the specific heat capacity of gases at constant volumes, and the meldometer, to determine the melting point of tiny samples of materials, such as archaeological and other valuable artefacts, and in identifying geological minerals. This ingenious Irish polymath is buried at Mount Jerome in Dublin.

You can read about Joly's contribution to physics in a new book, Physicists of Ireland: Passion and Precision, edited by Mark McCartney and Andrew Whitaker, Institute of Physics, £40 in UK.

Joly also features in Ingenious Ireland, Mary Mulvihill's new book, TownHouse, €30