A pilot study for early evaluation and estimation of prognosis of patients with advanced and/or relapsed breast cancer by endocrine and/or CDK4/6 inhibitor combined therapy using estrogen receptor PET - A pilot study for breast cancer by endocrine and/or CDK4/6 inhibitor combined therapy using estrogen receptor PET

We compared the values of the positive therapy response (RP) group (lesions with a decrease in the FDG SUVmax >=30% after treatment) and the negative therapy response (RN) group (lesions with a decrease in the FDG SUVmax <30%). The FES SUVmax was significantly different in both groups before (RPpre and RNpre) and after (RPpost and RNpost) treatment. The FES value was high before treatment and low after treatment. A decrease trend like FES changes was observed for the FDG SUVmax).