Implementation of Multi-Curie Production of (99m)Tc by Conventional Medical Cyclotrons.
(99m)Tc is currently produced by an aging fleet of nuclear reactors, which require enriched uranium and generate nuclear waste. We report the development of a comprehensive solution to produce (99m)Tc in sufficient quantities to supply a large urban area using a single medical cyclotron.


METHODS
A new target system was designed for (99m)Tc production. Target plates made of tantalum were coated with a layer of (100)Mo by electrophoretic deposition followed by high-temperature sintering. The targets were irradiated with 18-MeV protons for up to 6 h, using a medical cyclotron. The targets were automatically retrieved and dissolved in 30% H2O2. (99m)Tc was purified by solid-phase extraction or biphasic exchange chromatography.


RESULTS
Between 1.04 and 1.5 g of (100)Mo were deposited on the tantalum plates. After high-temperature sintering, the (100)Mo formed a hard, adherent layer that bonded well with the backing surface. The targets were irradiated for 1-6.9 h at 20-240 μA of proton beam current, producing up to 348 GBq (9.4 Ci) of (99m)Tc. The resulting pertechnetate passed all standard quality control procedures and could be used to reconstitute typical anionic, cationic, and neutral technetium radiopharmaceutical kits.


CONCLUSIONS
The direct production of (99m)Tc via proton bombardment of (100)Mo can be practically achieved in high yields using conventional medical cyclotrons. With some modifications of existing cyclotron infrastructure, this approach can be used to implement a decentralized medical isotope production model. This method eliminates the need for enriched uranium and the radioactive waste associated with the processing of uranium targets.
BC Cancer Agency, Vancouver, British Columbia, Canada Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada fbenard@bccrc.ca.
François
F
Bénard
TRIUMF, Vancouver, British Columbia, Canada.
Kenneth R
KR
Buckley
BC Cancer Agency, Vancouver, British Columbia, Canada TRIUMF, Vancouver, British Columbia, Canada.
Thomas J
TJ
Ruth
TRIUMF, Vancouver, British Columbia, Canada.
Stefan K
SK
Zeisler
BC Cancer Agency, Vancouver, British Columbia, Canada.
Julius
J
Klug
TRIUMF, Vancouver, British Columbia, Canada.
Victoire
V
Hanemaayer
BC Cancer Agency, Vancouver, British Columbia, Canada.
Milan
M
Vuckovic
Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.
Xinchi
X
Hou
Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.
Anna
A
Celler
BC Cancer Agency, Vancouver, British Columbia, Canada.
Jean-Pierre
JP
Appiah
Centre for Probe Development and Commercialization and McMaster University, Hamilton, Ontario, Canada; and.
John
J
Valliant
Lawson Research Institute, London, Ontario, Canada.
Michael S
MS
Kovacs
Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada TRIUMF, Vancouver, British Columbia, Canada.
Paul
P
Schaffer
D017357:Cyclotrons; D008854:Microscopy, Electron; D008982:Molybdenum / Q000737:chemistry; D011786:Quality Control; D011854:Radiochemistry / Q000295:instrumentation*; D013670:Sodium Pertechnetate Tc 99m / Q000302:isolation & purification; D013667:Technetium / Q000737:chemistry*
D013667:Technetium; D008982:Molybdenum; D013670:Sodium Pertechnetate Tc 99m
99mTc; cyclotron; molybdenum; radioisotope production