Promising PET FAPI Tracer for Diagnosing Breast Cancer

A new PET tracer based on gallium-68 (Ga-68) and targeting fibroblast activation protein has shown promise in detecting primary and metastatic tumors in women with advanced breast cancer using whole-body MRI, according to a German study published in Radiology.

“Simultaneous gallium 68 (68Ga) fibroblast-activation protein (FAP) inhibitor–46 breast PET/MRI followed by whole-body scanning targeting the FAP showed excellent imaging characteristics and added diagnostic value to local breast cancer, lymph nodes, and whole-body staging,” wrote the team, based in the University of Muenster.

“‘[Ga-68 FAPI-46] PET/MRI showed strong and reliable accumulation in invasive cancer … and provided contrast even for the detection of subcentimeter lesions,’ wrote first authors Drs. Philipp Backhaus and Matthias Burg,” according to Morton.

“Overall…the research shows considerable promise for the application of Ga-68 FAPI-46 PET in breast cancer for staging and possibly for primary breast cancer diagnosis, the authors wrote,” according to Morton.


Backhaus, Philipp; Burg, Matthias C.; Roll, Wolfgang; Büther, Florian; Breyholz, Hans-Jörg; Weigel, Stefanie; Heindel, Walter; Pixberg, Michaela; Barth, Peter; Tio, Joke; Schäfers, Michael. Simultaneous FAPI PET/MRI Targeting the Fibroblast-Activation Protein for Breast Cancer. Radiology. Published online October 12, 2021, at Accessed October 30,2021.

Morton, Will. PET tracer shows promise for diagnosing breast cancer. October 14, 2021, at Accessed October 30, 2021.

Illustrative of typical breast MRI. Not an image from the study cited.