QIBA Profiles and protocols
A QIBA Profile is a document used to organize and record the results of collaborative work by QIBA members.
The process specifies what should be achieved, rather than how to achieve it. The document includes one or more performance claims, which tell users what quantitative results can be achieved by following the Profile.
Profile details serve two purposes:
- Advise vendors what must be implemented in their product.
- Communicate the necessary procedures to users.
For each biomarker, QIBA Coordinating Committees initially determine what Profiles to pursue and what key scientific precursor questions and concepts need validation. The committee then coordinates the research and resolves any identified issues through the public comment period.
Profile development addresses:
- Clinical context
- Profile claims
- Profile details
These processes and Profiles are intended to increase acceptance of quantitative imaging biomarkers by the imaging community, clinical trial industry, and regulatory agencies as proof of biological, proof of changes in pathophysiology, and surrogate end-points for changes in the health status of patients. The process also addresses obstacles faced by suppliers seeking to commercialize imaging biomarker tests, which should lead to wider availability and use of imaging biomarkers.
Biomarker Committee and Task Forces, comprised of clinicians and medical physicists, define the clinical context (such as disease staging, clinical manifestations, etc.) to determine which biomarkers and correlating Profiles to pursue.
Biomarker Committees define the Profile claims by characterizing the currently accepted standard, stating how the new imaging biomarker will do better, and adopting a statistically rigorous framework. Results are recorded in the Profile, outlining the various claims in terms of science and supporting issues, such as interoperability or system support issues.
- Claim #1 (CT Volumetry): A measured volume change of more than 30% for a tumor provides at least a 95% probability that there is a true volume change; P(true volume change > 0% | measured volume change >30%) > 95%.
- Claim #2 (DCE-MRI): Quantitative microvascular properties, specifically transfer constant (Ktrans) and blood-normalized initial-area-under-the-gadolinium-concentration curve (IAUGCBN), can be measured from DCE-MRI data obtained at 1.5T using low-molecular-weight extracellular gadolinium-based contrast agents with a 20% within-subject coefficient of variation for solid tumors at least 2 cm in diameter.
Groundwork activities may include:
- Quality control metrics
- Rationale for covariates (such as patient preparation)
- Software version tracking
- Determination of performance claims (e.g., decide on what limits of variability to include in a claim)
Profile details bring together the results of clinical context, Profile claims, and groundwork to specify what is necessary to achieve the claim.
QIBA protocols are developed in conjunction with QIBA Profiles and clearly describe standardized imaging procedures to achieve reproducible quantitative endpoints on tests performed using systems that meet specific performance claims outlined in QIBA profiles. QIBA protocols follow the Uniform Protocols in Clinical Trials (UPICT) template and conventions.
UPICT facilitates development and maintenance of widely acceptable, consistent imaging protocols for use in clinical trials across a range of disease states, anatomic sites, and imaging modalities.
For more information explore the QIBA Wiki.