New technology for manufacturing radioisotopes for cancer diagnostic
18 September 2008
New technology developed at the Delft University of Technology in the
Netherlands could prevent global shortages of radio isotopes for cancer
diagnosis, according to an article by Prof. Bert Wolterbeek of Delft
University of Technology’s Reactor Institute Delft (RID) in the
university's journal Delta.
The shortage of radioisotopes made global headlines recently.
Hospitals are facing a shortage of radioisotopes which means that
patients will have to wait longer for cancer diagnosis (see
MTB Europe article). Only a handful of reactors
around the world manufacture the isotope, technetium-99m, which is used
to treat about forty million patients annually. Three of these reactors
are currently unable to supply any due to maintenance work, including
Europe’s most important: the Dutch reactor in Petten.
Additional isotope manufacturing would reduce the risk of shortages
considerably. The current process requires enriched uranium, for which
manufacturers need a special permit due to nuclear non-proliferation
Prof. Bert Wolterbeek of the RID is working on a radical solution to
this problem. He is developing a method for producing the sought-after
isotope without uranium. If these experiments prove to be applicable in
an industrial environment, many more factories could manufacture the
"Technetium-99m, the material in question, is currently made by
highly enriched uranium fission,” Prof. Wolterbeek explains. "One of the
products created is radioactive molybdenum-99, the raw material for
technetium-99m. Manufacturers supply this molybdenum to hospitals
secured in rods. A hospital can ‘harvest’ the technetium-99m isotope
from a rod for a week as the molybdeen-99 slowly decays into
Yet molybdenum-99 can also be manufactured from molybdenum-98, a
stable isotope made of natural molybdenum, a material which mining
companies already extract from the ground. Prof. Wolterbeek has patented
a technique in which he bombards this raw material with neutrons in
order to make molybdenum-99.
The molybdenum atoms are not just ‘activated’ by the neutron
bombardment, but are also separated from the surrounding atoms by the
energy transfer. The resultant molybdenum-99 can then be dissolved in
water. This means that the isotope can be produced in highly
concentrated form. And this aspect is crucial. Prof. Wolterbeek
explains: "The activity concentration of the radioactive material needs
to be high, otherwise patients will be given too high a chemical dose to
form a clear radiation image."
Prof. Wolterbeek wishes to hold larger-scale tests in conjunction
with Urenco. The head of the Stable Isotopes department at this
reprocessing company, Charles Mol, envisages the technology from Delft
University of Technology being used to open up a "highly interesting
In his view, scientists around the globe are desperately searching
for alternative manufacturing methods as the use of enriched uranium
will cease at some point due to nuclear non-proliferation treaties.
"Another reason," he says, "is that the current manufacturing process
produces a huge amount of radioactive waste. And any alternative method
using low-enriched uranium could produce even more waste."
The original article (in Dutch only):