Standardization in Radiobiology

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Objective for A.19.0

  • Establish dosimetry standards for use in x-ray and radionuclide-based radiation biology programs.

Background: With the increasing accuracy in radiation therapy and radiation biology techniques, the accuracy of clinical radiation therapy dosimetry has far outpaced the accuracy in radiobiology laboratories. Recent advances include the introduction of highly sophisticated small-field preclinical irradiators such as the irradiator shown in Figure 1. Field sizes as narrow as 0.5 mm in diameter are being implemented for small-animal biology studies. It has been shown that doses delivered in radiation biology laboratories are being delivered with innacuracies of up to 50% and sometimes more. Typical radiobiology irradiators include radionuclide-based systems (Cs-137 or Co-60) and x-ray based cabinet irradiators. Standard measurement protocols do not exist for either of these systems and users are assuming the nominal dose rates are accurate.

Evidence shows that the presumed doses delivered in radiation biology irradiators are not in agreement with the auditing doses measured by experienced radiation therapy dosimetry labs. Additionally, the articles being published do not report adequate details to reproduce the experiments performed.

With better accuracy in radiation biology experiments, applications of this would reach into other specialties such as radiation protection, homeland security, and the industry.

Figure 1 - Schematic of the XSTRAHL SAARP irradiator platform (image obtained from

Action Items:

1 – With cooperation between NIST, AAPM, AACR, and the NIH, standard measurement techniques need to be established through the use of standard operationg procedures (SOPs) and dosimetry equipment validation. The measurement techniques must include NIST-traceability and appropriate primary standard development / utilization.

Resource Requirements:

1 – Undetermined dollar amount - Partnerships between NIST, AAPM, AACR, and the medical community are essential in this area.