Head-to-Head Comparison of [¹⁸F]PSMA-1007 and [¹⁸F]FDG PET/CT in Patients with Triple-Negative Breast Cancer

Simple Summary: This study investigates a promising avenue for improving the diagnosis and treatment of triple-negative breast cancer (TNBC), a highly aggressive form of breast cancer with limited therapeutic options. The researchers focus on the prostate-specific membrane antigen (PSMA), known for its presence in prostate cancer but also identified in breast cancer. Using F-18-PSMA-1007 PET/CT, the study aims to assess PSMA's in vivo expression in TNBC patients and compare it with the standard [F-18]FDG PET/CT. The findings suggest that [F-18]PSMA-1007 PET/CT may outperform current methods in detecting distant metastases, especially in the brain. This research not only enhances our understanding of PSMA expression in TNBC but also hints at potential advancements in diagnostic imaging and targeted therapies for this challenging cancer type. Background: Triple-negative breast cancer (TNBC) exhibits high aggressiveness and a notably poorer prognosis at advanced stages. Nuclear medicine offers new possibilities, not only for diagnosis but also potentially promising therapeutic strategies. This prospective study explores the potential of prostate-specific membrane antigen (PSMA) as a diagnostic and therapeutic target in TNBC. Methods: the research investigates PSMA expression in vivo among TNBC patients using [F-18]PSMA-1007 PET/CT and compares it head-to-head with the standard-of-care [F-18]FDG PET/CT. Results: The study involves 10 TNBC patients, revealing comparable uptake of [F-18]PSMA-1007 and [F-18]FDG in primary and metastatic lesions. Nodal metastases were found in eight patients, showing similar SUVmax values in both modalities. Two patients had uncountable lung metastases positive in both [F-18]FDG and [F-18]PSMA-1007 scans. PET-positive bone metastases were identified by F-18-PSMA in four patients, while elevated [F-18]FDG uptake was found only in three of them. Distant metastases displayed higher SUVmax values in the [F-18]PSMA-1007 PET/CT, as compared to [F-18]FDG. Additionally, brain metastases were exclusively detected using [F-18]PSMA-1007. Conclusions: the findings provide valuable insights into the expression of PSMA in TNBC and underscore the potential clinical significance of [F-18]PSMA-1007 PET/CT in enhancing both diagnostic and therapeutic approaches for this aggressive breast cancer subtype.