710
M. Dohlus et al.
private funding, to introduce Sodium-24, Phosphorus-32, Cobalt-60, Technetium99, and Iodine-131 into medical practice. In 1941 the first cyclotron fully dedicated
to production of radionuclides for medical purposes was built at the Washington
University of St Louis and used for the production of radionuclides for diagnostic
and internal radiotherapy.
In the years that followed, the production of neutron-generated radioisotopes
was moved to more efficient nuclear reactors. Nevertheless a number of cyclotron
facilities, fully dedicated to medical applications, were built with the purpose of
continuing the research of new products. In the 1950s, the use of Thallium-201 as
tracer for cardiac flow revitalized the use of medical cyclotrons. Thallium-201 is
produced via Lead-201 generator obtained in cyclotron from protons or deuterons
beams.
In the late 1960s, a turning point that drastically transformed the medical
application of cyclotrons was the idea of developing the radiochemistry labs inside
the cyclotron facility, possibly close to the clinics where they were the patients
were injected. Organic molecules containing short-living positron-emitting isotopes
could be immediately transformed in pharmaceutical products and distributed in the
facilities of the region to be used within few hours. The most important product was
the Flourodeoxygloucose, FDG, made for the first time in 1976 with Fluorine-18, a
positron emitter with a half-live of 110 min [50]. FDG was developed by a scientific
collaboration of the Brookhaven National Laboratory, the US National Institute of
Health and the University of Pennsylvania with the purpose of studying the brain
metabolism.
Since then, FDG radiochemistry has evolved to fast and efficient production
processes and today it is used in 75% of PET medical imaging [51]. The applications
include diagnoses of brain diseases like epilepsy and dementia, examination of heart
functionality, and detection of evolution of many different tumours.
New radiopharmaceuticals labeled with short half-lives positron emitters (in particular Fluorine-18 and Carbon-11) are still studied and developed today. Although
Oxygen-15 is not commercially used for PET due to the fast decay time of 2 min,
the Company Ion Beam Applications (IBA), built a 3 MeV deuterium cyclotron
dedicated to the production of Oxygen-15 labeled gasses [52].
11.3.1.2 Accelerator for Radioisotope Production
Today the number of cyclotrons used for medical purposes, officially registered by
the last IAEA survey published in 2006, is 262 [53]. The real number is certainly
higher and it is increasing continuously by approximately 50 units per year, mainly
because of new small PET accelerators. A survey made in 2010 combining inputs
of production of the four major manufacturers already estimated in 671 the number
of cyclotrons in operation [54].
The technology of cyclotrons has advanced in parallel to the development of
PET. In the 1970s The Cyclotron Company (TCC) [55] studied the acceleration
on negatively charged hydrogen (H − ). The extraction of the beam is in this way
M. Dohlus et al.
private funding, to introduce Sodium-24, Phosphorus-32, Cobalt-60, Technetium99, and Iodine-131 into medical practice. In 1941 the first cyclotron fully dedicated
to production of radionuclides for medical purposes was built at the Washington
University of St Louis and used for the production of radionuclides for diagnostic
and internal radiotherapy.
In the years that followed, the production of neutron-generated radioisotopes
was moved to more efficient nuclear reactors. Nevertheless a number of cyclotron
facilities, fully dedicated to medical applications, were built with the purpose of
continuing the research of new products. In the 1950s, the use of Thallium-201 as
tracer for cardiac flow revitalized the use of medical cyclotrons. Thallium-201 is
produced via Lead-201 generator obtained in cyclotron from protons or deuterons
beams.
In the late 1960s, a turning point that drastically transformed the medical
application of cyclotrons was the idea of developing the radiochemistry labs inside
the cyclotron facility, possibly close to the clinics where they were the patients
were injected. Organic molecules containing short-living positron-emitting isotopes
could be immediately transformed in pharmaceutical products and distributed in the
facilities of the region to be used within few hours. The most important product was
the Flourodeoxygloucose, FDG, made for the first time in 1976 with Fluorine-18, a
positron emitter with a half-live of 110 min [50]. FDG was developed by a scientific
collaboration of the Brookhaven National Laboratory, the US National Institute of
Health and the University of Pennsylvania with the purpose of studying the brain
metabolism.
Since then, FDG radiochemistry has evolved to fast and efficient production
processes and today it is used in 75% of PET medical imaging [51]. The applications
include diagnoses of brain diseases like epilepsy and dementia, examination of heart
functionality, and detection of evolution of many different tumours.
New radiopharmaceuticals labeled with short half-lives positron emitters (in particular Fluorine-18 and Carbon-11) are still studied and developed today. Although
Oxygen-15 is not commercially used for PET due to the fast decay time of 2 min,
the Company Ion Beam Applications (IBA), built a 3 MeV deuterium cyclotron
dedicated to the production of Oxygen-15 labeled gasses [52].
11.3.1.2 Accelerator for Radioisotope Production
Today the number of cyclotrons used for medical purposes, officially registered by
the last IAEA survey published in 2006, is 262 [53]. The real number is certainly
higher and it is increasing continuously by approximately 50 units per year, mainly
because of new small PET accelerators. A survey made in 2010 combining inputs
of production of the four major manufacturers already estimated in 671 the number
of cyclotrons in operation [54].
The technology of cyclotrons has advanced in parallel to the development of
PET. In the 1970s The Cyclotron Company (TCC) [55] studied the acceleration
on negatively charged hydrogen (H − ). The extraction of the beam is in this way