Summary: A study presented at the 2024 Society of Nuclear Medicine and Molecular Imaging Annual Meeting found FAPI PET/CT more accurate than 18F-FDG PET/CT in staging newly diagnosed breast cancer, restaging about 20% of patients and improving clinical management.

Key Takeaways:

  1. Increased Accuracy: FAPI PET/CT was found to be more accurate in staging newly diagnosed breast cancer patients compared to 18F-FDG PET/CT, restaging nearly 20% of patients.
  2. Improved Management: The use of FAPI PET/CT led to optimized management plans for patients, including the additional detection of bone lesions and internal mammary lymph nodes.
  3. Potential for Better Outcomes: The study suggests that FAPI PET/CT could advance personalized treatment strategies, reduce unnecessary treatments, and improve outcomes for breast cancer patients, particularly those in stage IIA.


A study comparing fibroblast activation protein inhibitor (FAPI) and 18F-FDG PET/CT for staging newly diagnosed breast cancer found FAPI PET/CT to be more accurate. About 20% of patients were restaged using FAPI PET/CT, highlighting its clinical benefits. This research was presented at the 2024 Society of Nuclear Medicine and Molecular Imaging Annual Meeting.

Enhancing Breast Cancer Staging

18F-FDG PET/CT, while commonly used in breast cancer staging, has limitations, such as false positives in inflammatory breast lesions and reduced sensitivity in specific breast cancer subtypes. Previous small-sample retrospective studies suggest that 68Ga-FAPI might outperform 18F-FDG PET/CT with its high sensitivity in the detection of primary tumors and metastases among breast cancer patients.

“There is currently a lack of evidence on the efficacy of FAPI PET/CT, especially in large sample cohorts,” says Zhixin Hao, MD, a nuclear medicine physician atPeking Union Medical College Hospital in Beijing, China. “Our study sought to add to the literature by assessing FAPI PET/CT for the systemic staging of newly diagnosed breast cancer compared with 18F-FDG PET/CT.”

Inside the Study

A total of 121 patients newly diagnosed with breast cancer were included in the study. All patients underwent 18F-FDG imaging. In addition, 53 patients were imaged with 68Ga-FAPI-04 PET/CT and 68 patients were imaged with A118F-FAPI-04 PET/CT. Data was analyzed and lesions were recorded as positive if their uptake exceeded that of the adjacent background tissue. The TNM clinical stage was determined from 18F-FDG and FAPI PET/CT, according to the American Joint Committee on Cancer Staging Manual.

Compared to the clinical TNM stage determined by 18F-FDG PET/CT, FAPI re-staged 19.8% of patients. Management plans were optimized in six patients due to the additional detection of bone lesions and internal mammary lymph nodes.

Advancing Personalized Breast Cancer Treatment

Of note, FAPI PET/CT upstaged 21.7% of stage IIA patients by 18F-FDG PET/CT. According to Hao, patients with stage IIA BC should be considered for systemic staging with FAPI PET/CT at the time of initial diagnosis.

“This study is significant as it has the potential to advance personalized treatment strategies for breast cancer patients,” notes Hao. “FAPI PET/CT for the initial staging of breast cancer has the potential to reduce unnecessary treatments and improve patient outcomes.”

Featured image: Clinical stage changed by FAPI PET/CT categorized by 18F-FDG PET/CT in newly diagnosed breast cancer.