PT  - JOURNAL ARTICLE
AU  - Demmert, Tristan T.
AU  - Pomykala, Kelsey L.
AU  - Lanzafame, Helena
AU  - Pabst, Kim M.
AU  - Lueckerath, Katharina
AU  - Siveke, Jens
AU  - Umutlu, Lale
AU  - Hautzel, Hubertus
AU  - Hamacher, Rainer
AU  - Herrmann, Ken
AU  - Fendler, Wolfgang P.
TI  - Oncologic Staging with <sup>68</sup>Ga-FAPI PET/CT Demonstrates a Lower Rate of Nonspecific Lymph Node Findings Than <sup>18</sup>F-FDG PET/CT
AID  - 10.2967/jnumed.123.265751
DP  - 2023 Sep 21
TA  - Journal of Nuclear Medicine
PG  - jnumed.123.265751
4099  - http://jnm.snmjournals.org/content/early/2023/09/21/jnumed.123.265751.short
4100  - http://jnm.snmjournals.org/content/early/2023/09/21/jnumed.123.265751.full
AB  - Nonspecific lymph node uptake on 18F-FDG PET/CT imaging is a significant pitfall for tumor staging. Fibroblast activation protein α expression on cancer-associated fibroblasts and some tumor cells is less sensitive to acute inflammatory stimuli, and fibroblast activation protein–directed PET may overcome this limitation. Methods: Eighteen patients from our prospective observational study underwent 18F-FDG and 68Ga fibroblast activation protein inhibitor (FAPI) PET/CT scans within a median of 2 d (range, 0–22 d). Lymph nodes were assessed on histopathology and compared with SUV measurements. Results: On a per-patient basis, lymph nodes were rated malignant in 10 (56%) versus 7 (39%) patients by 18F-FDG PET/CT versus 68Ga-FAPI PET/CT scans, respectively, with a respective accuracy of 55% versus 94% for true lymph node metastases. Five of 6 (83%) false-positive nodes on the 18F-FDG PET/CT scans were rated true negative by the 68Ga-FAPI PET/CT scans. On a per-lesion basis, tumor detection rates were similar (85/89 lesions, 96%). Conclusion: 68Ga-FAPI PET/CT imaging demonstrated higher accuracy for true nodal involvement and therefore has the potential to replace 18F-FDG PET/CT imaging for cancer staging.