What is an Advanced Credentialing Audit?

An Advanced Credentialing Audit verifies a centre’s ability to accurately plan and deliver advanced radiotherapy techniques, such as IMRT, SBRT, VMAT, and Helical photon deliveries, or protons. It provides an assessment of the accuracy of dose calculation, delivery, and verification.

Scope and methodology

Advanced credentialing is typically performed using a complex dosimetry check involving irradiation of either a third-party anthropomorphic or dosimetric phantom, or a validated in-house phantom, in accordance with protocol-defined requirements. Measured dose distributions are compared with corresponding treatment planning system calculations to assess agreement using established metrics (e.g. distance-to-agreement or gamma analysis).

Credentialing validity and repeat requirements

Credentialing is granted for a specific combination of treatment planning system (including algorithm), treatment unit, and delivery technique. Treatment units are currently distinguished by delivery platform (e.g. linear accelerator or other rotational system), and advanced techniques are categorised according to delivery modality (static IMRT, dynamic IMRT, rotational techniques or SBRT). Beam distinctions, including flattened and flattening-filter-free modes, are considered where relevant to the trial.

A successfully completed Advanced Credentialing Audit is valid for participation in an individual trial. Repeat credentialing may be required when:

  • any component of the credentialed combination changes (e.g. treatment planning system, algorithm, treatment unit, or technique); or
  • credentialing results do not meet the trial-specific acceptance criteria; or
  • the disease site or treatment complexity is not considered comparable to that of the trial for which participation is sought.

Results provided by the audit provider are forwarded to the EORTC RTQA team and form the basis for credentialing decisions.

Advanced Credentialing Auditors

The EORTC does not provide a dose measurement/credentialing service. The following providers are suggested: