the sonimage study

Conditions: Breast Cancer

Summary: 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.

estrogen receptor positive (er+) breast cancer is the most common cancer and the most frequent cause of cancer-related death in women in the western world. cyclin-dependent kinase 4 and 6 (cdk 4/6) inhibitors improve outcome, when added to standard first- and second-line endocrine therapy. however, they also add patient- and financial burden due to (long term) increased toxicity and hospital visits. therefore, benefits of additional cdk 4/6 inhibitors should be weighed against their burden. tools to support such treatment decisions by patients and providers are currently lacking. whole body heterogeneity of er expression, measured by 16α-\[18f\]fluoro-17β-estradiol (fes)-pet scan and 18f-fluorodeoxyglucose (fdg)-pet scan was related to time to progression on combined treatment in previous work. therefore in sonimage a baseline fes-pet is added to conventional work up, in 100 patients with er+ mbc who will receive first line endocrine treatment ± cdk 4/6 inhibition within the sonia study. the objectives are 1. to correlate pfs1 (according to sonia criteria) to baseline fes/fdg-pet heterogeneity; 2. to assess interaction between baseline fes/fdg-pet heterogeneity, treatment allocation, and pfs1 (according to sonia criteria); 3. to correlate response measurements of individual lesions to baseline fes/fdg heterogeneity and detailed fes/fdg imaging features; 4. to develop a multivariable model to predict individual pfs benefit to first-line ai ± cdk 4/6 inhibition, based on detailed fes/fdg image features and standard clinicopathological information, in n=100 sonia patients; 5. to validate this prediction model in two independent patient cohorts with baseline fes/fdg-pet scans (dutch impact-mbc trial; international et-transcan trial). 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. particularly for the approximately 25% of patients with er+ mbc who have an excellent- or poor outcome despite cdk 4/6 inhibition in the first-line, this could have profound implications, as they may refrain from combined treatment. ultimately, this could potentially contribute to fes/fdg-pet based treatment decisions in clinical practice, reduction of unnecessary toxicity and costs, while improving patient outcome and qol.

Eligibility criteria:
inclusion criteria: 1. patient is eligible and participates in the sonia trial for er+ mbc. 2. able to give written informed consent and to comply with the sonimage protocol. 3. documentation of histologically confirmed diagnosis of estrogen receptor (er) expression \>10% breast cancer based on local results. the receptor status can be determined on the primary tumor or on a tumor biopsy of a metastatic lesion. exclusion criteria: 1. a patient who meets the exclusion criteria of the sonia trial (see sonia protocol). 2. contra-indication for pet imaging. 3. use of estrogen receptor ligands (i.e. tamoxifen or fulvestrant) ≤ 5 weeks before fes-pet imaging.