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Target foil rupture scenario and provision for handling different models of medical cyclotrons used in India.

Shaiju VS, Sharma SD, Kumar R, Sarin B - J Med Phys (2009)

Bottom Line: Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions.It is found that the induced activity in the target foil increases with its successive usages.As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron.

View Article: PubMed Central - PubMed

Affiliation: Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai - 400 094, India.

ABSTRACT
Medical cyclotron is a particle accelerator used in producing short lived radiotracers such as (18)F, (11)C, (15)O, (13)N etc. These radiotracers are labeled with suitable pharmaceuticals for use to gather information related to metabolic activity of the cell using Positron Emission Tomography (PET) scan. Target foil rupture is considered one of the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron. Recommendations have also been made to reduce personal exposure while handling the target foil rupture condition such as the use of L-Bench near the target area and participation of experienced personnel.

No MeSH data available.


Related in: MedlinePlus

Target assembly of a medical cyclotron containing Havar foils
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Figure 0002: Target assembly of a medical cyclotron containing Havar foils

Mentions: The beam enters the target chamber through a double-foil assembly. The target assembly consists of a front flange, helium cooling flange, target chamber and a rear flange as shown in Figure 2. Target chamber is made up of silver. The front flange supports the beam into the target chamber for irradiation. Two thin metal foil windows (Havar foils) are used to separate the target chamber from the cyclotron vacuum. Havar foil forms the entrance of proton beam into a highly pressurized 18O enriched water target used for the production of 18F. Havar is an alloy containing cobalt (42.5%), chromium (20%), nickel (13%), tungsten (2.8%), molybdenum (2%), manganese (1.6%), carbon (0.2%), beryllium (0.04%), and iron (balance).[4] This cobalt base alloy has no magnetic attraction and high melting point. In the target assembly, the front side and the rear side Havar foils have an approximate thickness of 50 μm and 25 μm respectively. High speed re-circulating helium gas is used for Havar foil cooling. Cooling water is also circulated from the rear side of the target assembly whenever the system selects the target.


Target foil rupture scenario and provision for handling different models of medical cyclotrons used in India.

Shaiju VS, Sharma SD, Kumar R, Sarin B - J Med Phys (2009)

Target assembly of a medical cyclotron containing Havar foils
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2807682&req=5

Figure 0002: Target assembly of a medical cyclotron containing Havar foils
Mentions: The beam enters the target chamber through a double-foil assembly. The target assembly consists of a front flange, helium cooling flange, target chamber and a rear flange as shown in Figure 2. Target chamber is made up of silver. The front flange supports the beam into the target chamber for irradiation. Two thin metal foil windows (Havar foils) are used to separate the target chamber from the cyclotron vacuum. Havar foil forms the entrance of proton beam into a highly pressurized 18O enriched water target used for the production of 18F. Havar is an alloy containing cobalt (42.5%), chromium (20%), nickel (13%), tungsten (2.8%), molybdenum (2%), manganese (1.6%), carbon (0.2%), beryllium (0.04%), and iron (balance).[4] This cobalt base alloy has no magnetic attraction and high melting point. In the target assembly, the front side and the rear side Havar foils have an approximate thickness of 50 μm and 25 μm respectively. High speed re-circulating helium gas is used for Havar foil cooling. Cooling water is also circulated from the rear side of the target assembly whenever the system selects the target.

Bottom Line: Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions.It is found that the induced activity in the target foil increases with its successive usages.As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron.

View Article: PubMed Central - PubMed

Affiliation: Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai - 400 094, India.

ABSTRACT
Medical cyclotron is a particle accelerator used in producing short lived radiotracers such as (18)F, (11)C, (15)O, (13)N etc. These radiotracers are labeled with suitable pharmaceuticals for use to gather information related to metabolic activity of the cell using Positron Emission Tomography (PET) scan. Target foil rupture is considered one of the major emergency situations during medical cyclotron operations because there is a potential of over exposure to the working personnel. Radiation protection survey of a self-shielded medical cyclotron installation was carried out during normal and emergency conditions. It is found that the induced activity in the target foil increases with its successive usages. As a case study, we have evaluated the emergency handling procedures of GE PETtrace-6 medical cyclotron. Recommendations have also been made to reduce personal exposure while handling the target foil rupture condition such as the use of L-Bench near the target area and participation of experienced personnel.

No MeSH data available.


Related in: MedlinePlus