⁶⁸Ga-FAPI-04 PET/CT has high diagnostic efficacy in Tg-positive and Tg-negative differentiated thyroid cancer
6 affiliations
- 1Department of Nuclear Medicine, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
- 2Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province, Luzhou, Sichuan, China
- 3Laboratory for Targeted Radiopharmaceuticals Creation, Luzhou, Sichuan, China
- 4Institute of Nuclear Medicine, Southwest Medical University, Luzhou, Sichuan, China
- 5Department of General Practice, Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China
- 6Department of Pathology, Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan, China
Abstract
Background: Thyroglobulin (Tg) is a standard biomarker for monitoring differentiated thyroid carcinoma (DTC) after radioiodine therapy, yet its reliability is compromised by false-positive and false-negative results. This study aimed to evaluate the diagnostic performance of 68Ga-FAPI-04 PET/CT, an emerging imaging modality, for detecting recurrence and metastasis in DTC patients, regardless of their Tg status. Methods: This retrospective study included patients with suspected or confirmed metastatic DTC who underwent 68Ga-FAPI-04 PET/CT between October 2022 and May 2025. All participants underwent 68Ga-FAPI-04 PET/CT and Tg testing, with histopathology or clinical follow-up as the reference standard. The sensitivity, specificity, and accuracy of both methods were compared. Quantitative analysis was performed using the target-to-background ratio (TBR). Results: Among 99 patients in a TSH-suppressed state, 68Ga-FAPI-04 PET/CT demonstrated superior diagnostic accuracy (95.96%) compared to Tg testing (91.92%). In 48 TSH-stimulated patients, PET/CT maintained perfect accuracy (100%), outperforming Tg (97.92%). Notably, PET/CT successfully identified metastatic lesions in eight Tg-negative patients, primarily lymph node metastases. Using the mediastinum as a background for TBR calculation further enhanced the diagnostic efficacy for lymph node metastases, with the optimal threshold being 1.428, and achieving an accuracy and true positive rate of 0.98. Conclusion: 68Ga‑FAPI‑04 PET/CT exhibits high accuracy for diagnosing recurrence and metastasis in DTC, and importantly can identify lesions in Tg‑negative patients.
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BibTeX
@article{mou2026⁶⁸gafapi04,
title = {{⁶⁸Ga-FAPI-04 PET/CT has high diagnostic efficacy in Tg-positive and Tg-negative differentiated thyroid cancer}},
author = {Lixian Mou and Ting Zhang and Xiaoling Zhang and Jian Zhou and Yue Chen and Wei Wang},
journal = {PLOS One},
year = {2026},
month = sep,
doi = {10.1371/journal.pone.0355343},
url = {https://doi.org/10.1371/journal.pone.0355343},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - ⁶⁸Ga-FAPI-04 PET/CT has high diagnostic efficacy in Tg-positive and Tg-negative differentiated thyroid cancer
AU - Lixian Mou
AU - Ting Zhang
AU - Xiaoling Zhang
AU - Jian Zhou
AU - Yue Chen
AU - Wei Wang
PY - 2026
DA - 2026/09/03
JO - PLOS One
DO - 10.1371/journal.pone.0355343
UR - https://doi.org/10.1371/journal.pone.0355343
AB - Background: Thyroglobulin (Tg) is a standard biomarker for monitoring differentiated thyroid carcinoma (DTC) after radioiodine therapy, yet its reliability is compromised by false-positive and false-negative results. This study aimed to evaluate the diagnostic performance of 68Ga-FAPI-04 PET/CT, an emerging imaging modality, for detecting recurrence and metastasis in DTC patients, regardless of their Tg status. Methods: This retrospective study included patients with suspected or confirmed metastatic DTC who underwent 68Ga-FAPI-04 PET/CT between October 2022 and May 2025. All participants underwent 68Ga-FAPI-04 PET/CT and Tg testing, with histopathology or clinical follow-up as the reference standard. The sensitivity, specificity, and accuracy of both methods were compared. Quantitative analysis was performed using the target-to-background ratio (TBR). Results: Among 99 patients in a TSH-suppressed state, 68Ga-FAPI-04 PET/CT demonstrated superior diagnostic accuracy (95.96%) compared to Tg testing (91.92%). In 48 TSH-stimulated patients, PET/CT maintained perfect accuracy (100%), outperforming Tg (97.92%). Notably, PET/CT successfully identified metastatic lesions in eight Tg-negative patients, primarily lymph node metastases. Using the mediastinum as a background for TBR calculation further enhanced the diagnostic efficacy for lymph node metastases, with the optimal threshold being 1.428, and achieving an accuracy and true positive rate of 0.98. Conclusion: 68Ga‑FAPI‑04 PET/CT exhibits high accuracy for diagnosing recurrence and metastasis in DTC, and importantly can identify lesions in Tg‑negative patients.
SN - 1932-6203
ER -