Medical

Radiation can be used for both diagnostics and therapeutic applications in nuclear medicine. In each case, Wolfmet tungsten alloy provides the perfect solution for radiation shielding and collimators. Its excellent radiation attenuation properties allow the thickness of shields to be reduced, while still effectively blocking harmful X-ray and gamma radiation. Wolfmet tungsten alloy is resistant to surface chips and dents that can harbour bacteria, making it easy to clean and sterilise.

We can also produce components using our additive manufacturing process – Wolfmet 3D. It is especially ideal for the manufacture of high-precision components such as collimators and radiation shields in imaging systems.

In pre-molecular imaging a collimator is used to direct radiation emitted by the subject onto a detector, and to minimise the number of stray photons.

Traditionally, Wolfmet has been used to make pinhole collimators.
However, with the introduction of Wolfmet 3D production, more complex types of collimator are now possible. Read our latest case study for more details.

Wolfmet’s high density ensures that septal penetration is reduced and as a consequence a higher resolution is achieved than when using a lead collimator.

In nuclear medicine, there is a need to house radioactive sources safely, so vials of radiopharmaceuticals are held in tungsten shields while the dose is drawn up into a syringe ready for treatment. Using Wolfmet tungsten alloy for this purpose reduces the finger dose received by medical staff, protecting them from exposure to harmful levels of radiation. Its density also enables the thickness of the shields to be reduced, making them easier to handle.

Using Wolfmet tungsten alloy isotope containers offers several important advantages over traditional lead containers:

• Non-toxic, removing the need for paint or encasement to prevent direct contact with skin
• Physically strong, scratch and dent resistant, making it easier to clean and sterilise
• Higher level of density and subsequent radiation attenuation allows containers to be reduced in size, so easier to handle

Where physicians prescribe radiotherapy for external or internal application, it is essential to minimise damage to healthy cells surrounding a tumour, and protect medical personnel from contact with the radiation.

External beam radiotherapy

Here, a multi-leaf collimator directs beams of radiation as precisely as possible on to a tumour. The collimator consists of thin tungsten leaves that can be moved independently to create a frame for the beam of radiation. The Wolfmet team excels in machining Wolfmet tungsten alloy, meaning the thin sheet can be manufactured to very tight tolerances, meeting the requirements needed.

HDR brachytherapy

High dose rate (HDR) brachytherapy consists of implanting a radioactive seed directly into a tumour for a pre-determined amount of time. Wolfmet tungsten alloy is an ideal material for safe containment of the radioactive seed both before and after the procedure because of its excellent attenuation characteristics for x-ray and gamma radiation.

As medical isotopes need to be transported over progressively longer distances, it is now a common approach to increase the activity levels of the isotopes so that an optimal residual activity remains on arrival. However, this presents a challenge to increase shielding without adversely affecting the overall size of the transport containers. Thanks to its high density and superior attenuation characteristics, Wolfmet tungsten alloy offers effective shielding in a compact form that can easily withstand the rigors of transportation.

Shielding can either be manufactured entirely from Wolfmet tungsten alloy or a Wolfmet tungsten alloy core can be added to the main lead shield, which can be a cost effective way to enhance capability.