18F-FFNP

This phase II trial tests the accuracy of functional imaging (FFNP)-positron emission tomography (PET)/computed tomography (CT) to predict response to abemaciclib plus endocrine therapy. Abemaciclib is a drug used to treat certain types of hormone receptor positive (HR+), HER2 negative breast cancer. Abemaciclib blocks certain proteins, which may help keep tumor cells from growing. Endocrine therapy adds, blocks, or removes hormones that can cause cancer to grow. FFNP PET imaging is a form of x-ray that uses FFNP as an imaging agent that may provide more precise information about the location of tumors that "light up" with FFNP than a PET scan alone can provide.

Purpose: The purpose of this study is to evaluate FFNP PET/MRI's utility for predicting response to Levonorgestrel-releasing Intrauterine Device (LR-IUD) hormonal therapy for Complex Atypical hyperplasia (CAH) and Endometrial Cancer (EC).
Participants: Eight women with histologically confirmed CAH or Grade 1 EC who have planned treatment with LR-IUD will be recruited..
Procedures (methods): The is a prospective, single arm, pilot study of 8 participants who will receive one FFNP PET/MRI scan. Medical records will be followed for 6 months.