Beam spoiler

1. REDIRECT Radiation therapy

Beam Spoiler

A beam spoiler is a device used in radiation therapy to modify the characteristics of a radiation beam before it reaches the patient. Beam spoilers are typically used in external beam radiation therapy to ensure that the dose distribution is optimal for treating superficial tumors while sparing deeper tissues.

Purpose and Function

The primary purpose of a beam spoiler is to increase the surface dose of a radiation beam. In radiation therapy, high-energy photon beams, such as those produced by a linear accelerator, have a build-up region where the dose increases with depth before reaching a maximum. This can result in insufficient dose to superficial tumors. A beam spoiler is placed in the path of the beam to scatter and attenuate the photons, effectively shifting the build-up region closer to the surface.

Design and Materials

Beam spoilers are typically made of materials such as acrylic or polystyrene, which are chosen for their ability to scatter radiation effectively without significantly absorbing it. The thickness and material of the spoiler are selected based on the energy of the beam and the desired modification of the dose distribution.

Clinical Applications

Beam spoilers are commonly used in the treatment of:

• Skin cancer
• Head and neck cancer
• Breast cancer

In these cases, the tumors are often located close to the surface, and the use of a beam spoiler helps ensure that the prescribed dose is delivered to the tumor while minimizing exposure to deeper tissues.

Advantages and Limitations

The use of beam spoilers offers several advantages:

• Improved dose distribution for superficial tumors
• Enhanced control over the depth of maximum dose

However, there are also limitations:

• Increased scatter can lead to higher doses to surrounding tissues
• Requires careful planning and verification to ensure optimal results

Also see

• Radiation therapy
• Linear accelerator
• Radiation dose
• Radiation oncology