title: A virtual clinical trial comparing static versus dynamic PET imaging in measuring response to breast cancer therapy.
abstract: We developed a method to evaluate variations in the PET imaging process in order to characterize the relative ability of static and dynamic metrics to measure breast cancer response to therapy in a clinical trial setting. We performed a virtual clinical trial by generating 540 independent and identically distributed PET imaging study realizations for each of 22 original dynamic fluorodeoxyglucose (18F-FDG) breast cancer patient studies pre- and post-therapy. Each noise realization accounted for known sources of uncertainty in the imaging process, such as biological variability and SUV uptake time. Four definitions of SUV were analyzed, which were SUVmax, SUVmean, SUVpeak, and SUV50%. We performed a ROC analysis on the resulting SUV and kinetic parameter uncertainty distributions to assess the impact of the variability on the measurement capabilities of each metric. The kinetic macro parameter, Ki, showed more variability than SUV (mean CV Ki=  17%, SUV  =  13%), but Kipre- and post-therapy distributions also showed increased separation compared to the SUV pre- and post-therapy distributions (mean normalized difference Ki=  0.54, SUV  =  0.27). For the patients who did not show perfect separation between the pre- and post-therapy parameter uncertainty distributions (ROC AUC  <  1), dynamic imaging outperformed SUV in distinguishing metabolic change in response to therapy, ranging from 12 to 14 of 16 patients over all SUV definitions and uptake time scenarios (p  <  0.05). For the patient cohort in this study, which is comprised of non-high-grade ER+  tumors, Kioutperformed SUV in an ROC analysis of the parameter uncertainty distributions pre- and post-therapy. This methodology can be applied to different scenarios with the ability to inform the design of clinical trials using PET imaging.
authors.affiliation: Department of Bioengineering, University of Washington, 3720 15th Avenue NE, Seattle, 98195 WA, United States of America.
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Wangerin
authors.forename: Mark
authors.initials: M
authors.lastname: Muzi
authors.forename: Lanell M
authors.initials: LM
authors.lastname: Peterson
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Linden
authors.forename: Alena
authors.initials: A
authors.lastname: Novakova
authors.forename: David A
authors.initials: DA
authors.lastname: Mankoff
authors.forename: Paul E
authors.initials: PE
authors.lastname: Kinahan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D003198:Computer Simulation; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods* / Q000592:standards; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18