The Belgian historical expertise in medical applications of ionising radiation

Belgium is a world leader in medical applications of ionising radiation. This leadership has been achieved thanks to the creativity and the innovations by hundreds of scientists, clinicians and engineers who built on the very strong foundations provided by the pioneers in the field.

A world leader inmedical applications of ionising radiation

At the end of the 19th and beginning of the 20th century, Belgium being one of the richest countries per habitant in the world was very much oriented towards scientific discoveries and technological developments. As an example, in April 1896, only five months after the discovery of X-rays by Roentgen, the Belgian army had X-ray equipment installed to improve medical diagnosis.

In March 1896, Henri Becquerel discovered rays of unknown nature. Shortly afterwards, Marie and Pierre Curie would explain the origin of the rays and coin the term radioactivity.

Leg of Belgian soldier, 1896

Source: 100 years of radiology in Belgium, Belgian Museum of Radiology, ISBN 90-802575-1-6

Pierre and Marie Curie-Skłodowska, 1904

The discovery ofRadium

Marie and Pierre Curie discovered the existence of radium in 1898 and successfully isolated radium salts in 1902. On year later, they shared the Nobel prize in physics with Henri Becquerel. The potential of radium for therapeutic uses was realised soon afterwards when both Becquerel and Pierre Curie experienced skin lesions after having been exposed to radium.

Marie Curie became a frequent visitor to Belgium, both for scientific reasons, e.g. the Solvay Conferences, and also because Belgium had the largest uranium reserves in the world thanks to the Shinkolobwe mine in Congo. Marie Curie extracted radium out of the uranium ore to supply radiotherapy services worldwide.

Treatment of Lupus by X-rays

In Belgium, already in 1900, Prof. Jules De Nobele, of (R)UGent, was using X-rays to treat Lupus by X-rays and in 1904, Prof Adrien Bayet of ULBruxelles, initiated treatment by radium.


Jules De Nobele and Adrien Bayet (source: Wikipedia)

Marie and Irène Curie Hoogstaede

Message to H.M. King Albert by attendants of the First Solvay Conference, 1911
(Source: Fondation Universitaire/Universitaire Stichting)

Marie and Irène Curie Hoogstaede

Marie and Irène Curie, Hoogstade, 1915
(Source: Roseline Debaillie)

During World War I, Marie Curie and her daughter Irène would spend a several weeks in Belgium, training Belgian nurses and doctors in radiography.

A major producer of Radium for therapeutic uses

Thanks to the exploitation of the Shinkolobwe mine, the “Union Minière du Haut Katanga” had a near monopoly on radium supply between World War I and II. Until the end of the World War II, radium was the principal source of nuclear radiation for therapy, either for local brachytherapy or for external beam therapy.

The Belgian Red Cross founded the Belgian Radium Institute in 1923 and in 1931, the Sino-Belgian Radium Institute was created in Shanghai, now the Fudan University Shanghai Cancer Center, the major cancer specialty hospital in China.

The universities of Ghent, Brussels, Leuven/Louvain and Liège all received a significant amount of radium for medical use through the Belgian “University Foundation”. At Leuven university, in 1928, Prof. Joseph Maisin founded the “Institut du Cancer” with a dedicated therapeutic X-ray source as well as with the then most powerful “radium bomb” world-wide.

As opposed to clinical nuclear medicine, which only strongly developed after World War II once artificial radioisotopes became available, new radiotherapeutic technologies and procedures were continuously developed and applied during the entire interbellum. Radium-based interstitial brachytherapy was refined and X-ray tubes for röntgenotherapy, delivering voltages up to a few hundred kV, became available allowing deep cancers to be treated. In 1939, the Bordet Institute was founded with the fight against cancer as its mission. (The Bordet Instutute was named after Jules Bordet (1870-1961), Nobel Medicine 1919.)

Radium Institute

Sino-Belgian Radium Institute, 1931 (source: wikipedia)

first therapy with Sr-89

First bone scan, first dynamic study, 1940-1941

first therapy with Sr-89

First therapy with Sr-89, 1940-1941

Pioneerin the use of Strontium-89 for bone metastasis

Also in 1939, a freshly graduated MD from ULB, Charles Pecher, moved to Berkeley to work with the inventor of the cyclotron, Ernest Lawrence, and his brother John Lawrence. MD. Pecher wanted to develop a cure for the pain caused by bone metastasis using one of the newly discovered radioisotopes. In 1940-41, he demonstrated that Sr-89 (Strontium-89) is taken up by the bone, that the uptake dynamics were optimal for therapy and he performed the first successful therapies with Sr-89. If it hadn’t been for the fact that his work was classified as very secret – due to the link between Strontium and nuclear weapons research and therefore only rediscovered a few years ago – he would have been considered one of the great pioneers in nuclear medicine.

Belgium, a worldleader inmedical isoptope supply, cyclotron-based applications and installations for proton therapy

Nuclear medicine was introduced in most Belgian university hospitals in the late 40’s, early 50’s. This was also the period when the Belgian Nuclear Research Centre, SCK CEN, was created (1952).

In radiation oncology, Co-60 (Cobalt-60) produced in nuclear reactors replaced radium for teletherapy from the fifties on. The University of Liège pioneered by replacing its radium bomb by a Co-60 bomb and Julien Garsou introduced medical physics. Zénon Bacq (ULiège and ULB) and Joseph Maisin collaborated on radiobiology research, soon joined by a strong research team at SCK CEN.

With its research reactors BR1 and BR2, SCK CEN performed uranium target irradiation to produce medical isotopes, and its spin-off, the Institute for Radioelements, IRE, took care of their separation and purification. Belgium then (and is still doing so today) started providing medical radioisotopes on a regular basis to nuclear medical centres in Europe and worldwide.


Belgian radiation oncology pioneers
Joseph Maisin (source) Zénon Bacq (source) Suzanne Simon (source)


BR2 reactor (Source: SCK CEN)

Dedicated transport was set up and gave rise to specialised companies. The major Belgian universities developed training in radiochemistry, radiopharmacy and nuclear medicine as a subspecialty to internal medicine.

By 1975-1980, the entire value chain, from production of isotopes up to clinical research and practice was operational. Already in the 80’s, more than 100 nuclear medicine departments were active in the country.

The Belgian Society of Nuclear Medicine (BSNM, now called ‘BELNUC‘) was founded in 1978 by physicians who had previously been involved in an extended partnership with radiation therapy and radiology. The first president was Michel De Roo from KULeuven.

The European Society for Radiotherapy and Oncology, ESTRO, was founded in 1980 to establish radiation oncology as an independent specialty uniting all disciplines involved: clinical, physics, biology and technology. The Belgian founder was Emmanuel van der Schueren.

Until then, there was no specifically Belgian association in the field of radiation oncology. This led to the creation of ABRO-BVRO, now called BeSTRO. It is the scientific organisation of radiation oncology in Belgium, open to radiation oncologists, radiation physicists, radiobiologists, biomedici and radiation therapists.

Up to the mid-eighties, only reactor produced isotopes were routinely available in Belgium. The first Belgian cyclotron was built in 1947 at the university of Leuven/Louvain. As researcher with extensive experience in cyclotron technology, Yves Jongen went to work at Berkeley and upon his return created IBA in 1986.

Soon, all Belgian universities would be equipped with cyclotrons which would open the door to the introduction of Positron Emission Tomography, PET, mainly with F-18 (Fluor-18). By the year 2000, Belgium hosted the highest density per capita of nuclear medicine departments, cyclotrons and SPECT or PET cameras in the world.

Linear accelerators became standard equipment in the Belgian radiation oncology departments. The interuniversity “Particle” proton therapy centre in Leuven welcomed its first patients in 2020.

Belgium is worldleader in medical isoptope supply, cyclotron-based applications and installations for proton therapy. All nuclear medicine and radiation oncology departments now have strong interdisciplinary teams to ensure an optimal treatment for the patients.

From left to right: G.Merchie, Ulg; M.De Visscher, UCLouvain; M.Van Vaerenbergh, UGent; M.De Roo, KULeuven; A.Ermans, ULB; M.Jonckheer, VUB

Yves Jongen at IBA (Source: 2020-01-18 IBA)