The SONImage Study

SONImage is a multicenter prospective imaging side study, in which a baseline FES-PET is added to conventional work up, in 100 patients with ER+ MBC who will receive endocrine treatment ± CDK 4/6 inhibition within the SONIA study (NCT03425838). SONImage will be executed in two Dutch centers: UMCG and Amsterdam UMC-location VUMC. The aim of the SONImage study is to (1) assess the relationship between FES/FDG-PET heterogeneity patterns at baseline and PFS for first-line endocrine treatment ± CDK 4/6 inhibition in ER+ MBC, and (2) to further improve that by developing a prediction model, within the SONIA study. This molecular imaging based multivariable prediction model may provide a unique measure of benefit of adding CDK 4/6 inhibition to first-line endocrine treatment, allowing patients and providers to weigh individual benefits and (long term) burden for optimized treatment decisions.