A.10 External Beam Therapy

• Completed on March 19, 2014.

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Objective

• Coordinate the dosimetry protocols and establish new ones if so needed for different modalities of beam sources used for therapy:
  • A.10.0a X-ray beam therapy
  • A.10.0b Small photon beam therapy
  • A.10.0c Electron beam therapy

Actions

• In collaboration with cancer treatment centers, NIST and the ADCLs should harmonize protocols for external beam dose determinations. This will involve a selection of appropriate dosimeters for use in a clinical environment and studies amongst the existing external beam treatment center as to the inter-center precision of such dosimeter systems.

Requirements

• A minimum of 2 person-years per year over the next three year time period is required to launch into these objectives. Partnerships between NIST, ADCLs and the medical community are essential in this area.

Background

High energy electron beams (typically 4 to 25 MeV) are used for the treatment of certain cancers, i.e. skin, prostate and breast cancers. X-rays derived for such electron beam sources are also used in these areas for treatment purposes to attain greater depth of beam penetration. Such photon beams can also be delivered by directed gamma sources. Depending upon the cancer being treated, each of the source modalities have been proven to be effective. However, each source differs in dose-rate and a cross-correlation needs to be established amongst the dosimetry protocols developed for each of these modalities.