Intratumoral Heterogeneity of Primary Breast Cancer on 18F-FES PET/CT and dbPET Anticipated a Heterogeneous Response to Chemotherapy

Yurika Kitano; Kanae K Miyake; Yoichi Shimizu; Masahiro Kawashima; Yuji Nakamoto

doi:10.1097/RLU.0000000000005660

Intratumoral Heterogeneity of Primary Breast Cancer on 18F-FES PET/CT and dbPET Anticipated a Heterogeneous Response to Chemotherapy

Clin Nucl Med. 2025 Jan 20. doi: 10.1097/RLU.0000000000005660. Online ahead of print.

Authors

Yurika Kitano¹, Kanae K Miyake², Yoichi Shimizu¹, Masahiro Kawashima³, Yuji Nakamoto¹

Affiliations

¹ From the Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine Kyoto University, Kyoto, Japan.
² Department of Advanced Imaging in Medical Magnetic Resonance, Graduate School of Medicine Kyoto University, Kyoto, Japan.
³ Department of Breast Surgery, Graduate School of Medicine Kyoto University, Kyoto, Japan.

PMID: 39848225
DOI: 10.1097/RLU.0000000000005660

Abstract

A 59-year-old woman with cT3N3M1 invasive breast cancer (ER low positive, PgR positive, HER2 negative) underwent PET/CT and dedicated breast PET scans using 18F-FDG and 18F-fluoroestradiol (18F-FES). While most primary tumor regions displayed low FES uptake, regions of high FES uptake were also identified. Following chemotherapy with the paclitaxel and bevacizumab, 18F-FDG PET/CT demonstrated a favorable response, but residual disease was noted in areas with high FES uptake on the pretreatment images. This case illustrated that 18F-FES PET can depict intratumoral heterogeneity within the primary tumor, which was strongly associated with a heterogeneous response to subsequent chemotherapy.