SNMMI: New Study Suggests Merits of FAPI PET/CT for Breast Cancer Staging

Can fibroblast activation protein inhibitor (FAPI) PET/CT have an impact in staging for women with newly diagnosed breast cancer?

For the study, which was presented at the 2024 Society of Nuclear Medicine and Molecular Imaging (SNMMI) Annual Meeting, researchers compared clinical TNM staging between FAPI PET/CT and ¹⁸F-FDG PET/CT, which is commonly utilized in breast cancer staging. The cohort was comprised of 121 women with breast cancer. According to the study, 53 women had ⁶⁸Ga-FAPI-04 PET/CT, 68 study participants had A118F-FAPI-04 PET/CT and all patients had ¹⁸F-FDG PET/CT scans.

The researchers found that FAPI PET/CT, in comparison to TNM staging with ¹⁸F-FDG PET/CT, restaged 19.8 percent of patients (24/121). Assessment of axillary lymph node (ALN) status by FAPI PET/CT was a significant factor for 17 of 24 patients (70.8 percent) who had TNM restaging, according to the study authors.

Noting the challenges with 18F-FDG PET/CT with respect to reduced sensitivity in certain breast cancer subtypes and false positives with inflammatory breast lesions, the researchers said the study findings show that FAPI PET/CT can be a viable alternative.

“This study is significant as it has the potential to advance personalized treatment strategies for breast cancer patients,” noted lead study author Zhixin Hao, M.D., a nuclear medicine physician affiliated with Peking Union Medical College Hospital in Beijing, China. “FAPI PET/CT for the initial staging of breast cancer has the potential to reduce unnecessary treatments and improve patient outcomes.”

The researchers also pointed out that FAPI PET/CT down-staged 20.6 percent of women (7/34) with initial IIB staging andupstaged 21.7 percent of patients (10/46) with initial IIA staging.

“Patients with stage IIA (breast cancer) should be considered for systemic staging with FAPI PET/CT at the time of initial diagnosis,” emphasized Hao and colleagues.

Reference

1. Hao Z, Pan B, Yao R, Zhou Y, Sun Q, Huo L. FAPI versus 18F-FDG PET/CT for systemic staging of newly diagnosed breast cancer. Presented at the 2024 Society of Nuclear Medicine and Molecular Imaging Annual Meeting, June 8-11, Toronto, Canada. Available at: https://www.xcdsystem.com/snmmi/program/10OD8Tq/index.cfm . Accessed June 11, 2024.