How is Mo99 breakthrough calculated?

How is Mo99 breakthrough calculated?

Radiopharmaceutical Preparation The Morning Elution

1. 1000 mCi was eluted from the Tc99m/Mo99 generator in 10.0 mL.
2. The Moly breakthrough was 5.7 μCi.
3. To calculate Mo99 breakthrough apply the above formula.
4. Applying our numbers to determine Moly breakthrough: 5.7 μCi/1000 mCi = 0.0057 μCi/mCi.

What is the half-life of Mo-99?

66 hours
Because of its relatively short half-life (66 hours), Mo-99 cannot be stockpiled for use. It must be made on a weekly or more frequent basis to ensure continuous availability. The processes for producing Mo-99 and technetium generators and delivering them to customers are tightly scheduled and highly time dependent.

What is MO-99 breakthrough?

This is called “molybdenum breakthrough” and the 99Mo is referred to as a radionuclidic impurity. The risks with 99Mo relate to its unfavourable physical decay characteristics (beta decay and long half-life), which would cause an unnecessary radiation dose to patients.

What happens in a technetium-99m generator?

Tc-99m is radioactive because one or more of the protons and neutrons in its nucleus is in an excited state. Tc-99m decays into Tc-99 with a half-life of six hours and this makes it particularly well suited to use in the body: after one day (four half-lives) only 6.3% of the initial Tc-99m remains.

How do you elute a generator?

To elute the generator, a vial of sodium chloride (5, 10, or 20 mL) of intravenous infusion quality is placed onto the inlet spike. The eluate, Na99mTcO4, is collected by placing a sterile evacuated elution vial onto the collection needle.

What is elution in nuclear medicine?

When a saline solution is passed over the column, ion exchange results in the production of sodium pertechnetate. This can then be chemically manipulated to form a variety of compounds. The removal of the technetium by the passage of saline is known as elution.

What is Tc-99m used for?

Technetium-99m is used to image the skeleton and heart muscle in particular, but also for brain, thyroid, lungs, liver, spleen, kidney, gall bladder, bone marrow, salivary and lachrymal glands, heart blood pool, infection and numerous specialized medical studies.

How is Tc-99m produced?

It is produced as a decay product of Mo-99. It is developed by either fissioning uranium targets or bombarding non-radioactive molybdenum targets with neutrons. The isotopes of Mo-99 and technetium-99m have short half-lives – 66 hours for Mo-99 and just 6 hours for Tc-99m.

What is tc99m used for?

How does 99motc generate 99mTc?

The useful life of a 99Mo – 99mTc generator is about 3 parent half lives, or approximately one week. Mo-99 used in these generators is produced either by neutron irradiation of Mo-98 (98Mo + n → 99Mo + γ ) or by fission of U-235 (Uranium-235) in a nuclear reactor.

What solvent liquid is normally used to elute a Mo Tc generator?

A sterile isotonic saline solution must be provided for the elution step. In most designs the eluent will be obtained from a standard septum vial by attaching the vial to the generator using the inlet spike provided for this purpose.

How is indium 111 produced?

Indium-111 is produced in a cyclotron using a cadmium-112 target which is bombarded with protons to produce indium-111 by the (p,2n) reaction. The energies of the γ-ray emissions (171 and 245 keV) are higher than that of technetium-99m. Indium-111 forms complexes in which indium is present in the + 3 oxidation state.

How to calculate limit for Tc-99m generator elution?

Suggested times for factory test elutions: The following calculations were used: The ratio of Tc-99m to Mo-99 used in the above table was calculated using the equation: Limit = 0.15 µCi Mo-99 per 1 mCi Tc-99m at time of administration.

How much Mo-99 is in a Tc-99m generator?

Limit = 0.15 µCi Mo-99 per 1 mCi Tc-99m at time of administration. Calculations and a chart of Tc-99m expiration times based on Mo-99 breakthrough can be found here .

How is Mo-99 recovered from a technetium generator?

(b) Schematic diagram showing the internal structure of a typical technetium generator. The Mo-99 in the generators decays with about a 66-hour half-life to Tc-99m. The Tc-99m is typically recovered by passing a saline solution through the alumina column in the generator, a process known aselutingthe generator.

What can molybdenum-99 and Tc-99m do?

Plot of typical Mo-99 and Tc-99m activity on a logarithmic scale versus time for multiple elution of a technetium generator. There are numerous Tc-99mkits5for producing radiopharmaceuticals to examine the brain, kidney, heart, bone, liver, and lung.