Work

Clinical significance of diffuse [18F] AlF-NOTA-FAPI-04 uptake in the thyroid on PET/CT imaging

Year: 2025

Type: article

Abstract: Many patients undergoing [ 18 F] AlF-NOTA-FAPI-04 ( 18 F-FAPI) PET/CT demonstrated diffuse thyroid uptake. These findings created challenges for accurate interpretation due to the limited understanding of physiological and non-oncologic causes of diffuse 18 F-FAPI uptake in the thyroid. This retrospective study examined patients who underwent 18 F-FAPI PET/CT imaging with diffuse thyroid uptake. It quantitatively assessed normal thyroid uptake, compared 18 F-FAPI uptake between normal and diseased thyroids, and explored potential associations with diffuse thyroid uptake. The study may improve the accuracy of 18 F-FAPI PET/CT interpretation for thyroid and facilitate appropriate management of diffuse thyroid uptake on 18 F-FAPI PET/CT. A total of 38 patients were included in this study based on the inclusion criteria. The mean SUVmax, SUVmean, and TBR of normal thyroid were 7.09 ± 3.83, 4.24 ± 2.25 and 3.93 ± 1.73, respectively. Quantitative analysis revealed no significant asymmetry in 18 F-FAPI uptake between the right and left thyroid lobes (SUVmax: right 6.69 ± 2.96 vs. left 6.54 ± 3.28, p = 0.84; SUVmean: right 4.19 ± 1.73 vs. left 4.18 ± 1.97, p = 0.98), consistent with the diffuse uptake pattern observed. There was no significant correlation between Hashimoto thyroiditis, serum TSH levels, and the degree of diffuse thyroid uptake (all p > 0.05 for SUVmax, SUVmean, and TBR). Furthermore, no association was observed between sex, age, immunotherapy, and diffuse thyroid uptake ( p > 0.05). Diffuse uptake of 18 F-FAPI in the thyroid may not significantly relate to Hashimoto thyroiditis or abnormal serum TSH levels. Lesions on 18 F-FAPI PET/CT scans might be hard to detect due to the moderate uptake in normal thyroid tissue.

Source: EJNMMI Research

DOI: 10.1186/s13550-025-01231-9

Authors: Ying Kou, Wei Diao, Zhuzhong Cheng, Yutang Yao

Institutions: University of Electronic Science and Technology of China, Sichuan Cancer Hospital

Language: English

Topic: Peptidase Inhibition and Analysis

Subfield: Oncology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $3,190