Medical Physics Seminar – Monday, September 12, 2022
Design and Analysis Considerations for Clinical Trials Using Quantitative Imaging Biomarkers
Dr. Nancy Obuchowski
Vice Chairman, Quantitative Health Sciences Cleveland Clinic Lerner College of Medicine
Quantitative imaging is being increasingly used to diagnose disease, predict patients' outcomes, monitor treatment response, and identify eligible subjects for clinical trials. The technical performance characteristics of quantitative imaging measurements, namely bias, and precision, drive their utility at the bedside and in clinical trials. Precision describes the closeness of replicate measurements, while bias describes how the measurements differ from the true value. In this presentation, I first describe methods for the estimation and comparison of biomarkers' technical performance, then examine how these performance characteristics are used to design and analyze clinical trial and identify eligible trial subjects. Several examples illustrate the methods, including a trial with ultrasound shear wave speed measurements to diagnose liver cirrhosis, specific binding ratio measured on SPECT imaging to identify eligible subjects for a new Parkinson's disease intervention, and CT measured nodule volume changes to estimate doubling time.