Clinical Report: Characterization of FAPI Uptake Patterns in Advanced DTC

Overview

This study evaluates the use of 99mTc-FAPI-YQ3 SPECT/CT in characterizing FAPI uptake and metabolic-stromal diversity in advanced differentiated thyroid carcinoma (DTC). Further validation is necessary.

Background

Advanced differentiated thyroid carcinoma (DTC) poses significant treatment challenges, particularly in cases that are radioactive iodine (RAI)-refractory. The ability to accurately characterize tumor biology and heterogeneity is crucial for guiding treatment decisions. Molecular imaging techniques, such as FAPI-targeted imaging, may enhance the understanding of tumor microenvironments and improve patient management.

Data Highlights

Key Findings

• 99mTc-FAPI-YQ3 SPECT/CT demonstrated a mean tumor-to-background ratio (TBR) of 6.8.
• Out of 103 lesions, 52.4% were concordant FDG-positive/FAPI-positive.
• High detection rates were observed for thyroid-bed lesions (90.5%) and bone lesions (87.5%).
• The logistic-regression model for exploratory radiomics analysis showed AUC values of 0.951 in the training set.
• No FDG-negative/FAPI-negative lesions were found in the study.

Clinical Implications

The use of 99mTc-FAPI-YQ3 SPECT/CT may provide insights into the metabolic-stromal characteristics of advanced DTC.

Conclusion

Further studies are required for validation of 99mTc-FAPI-YQ3 SPECT/CT in evaluating FAPI uptake in advanced DTC.

Related Resources & Content

1. American Thyroid Association, ATA Guidelines & Statements, 2023 -- Professional Guidelines
2. SNMMI, SNMMI procedure standard/EANM practice guideline for nuclear medicine evaluation and therapy of differentiated thyroid cancer, 2022 -- Joint DTC Guidelines
3. Frontiers in Endocrinology — Comparison of 68Ga-FAPI and 18F-DOPA PET/CT in patients with medullary thyroid cancer
4. European Radiology — Role of Dual-Tracer PET/CT with [68Ga]FAPI-04 and [18F]FDG in the Initial Assessment of Gastric Cancer
5. The ASCO Post — Molecular Imaging May Improve the Staging and Treatment of Pancreatic Ductal Adenocarcinoma
6. European Radiology — Assessing the Diagnostic Accuracy of [18F]ALF-NOTA-FAPI-04 PET/CT in Gastric Cancer Compared to [18F]FDG PET/CT: A Comparative Analysis
7. Comparison of 68Ga-FAPI and 18F-DOPA PET/CT in patients with medullary thyroid cancer
8. Role of Dual-Tracer PET/CT with [68Ga]FAPI-04 and [18F]FDG in the Initial Assessment of Gastric Cancer
9. Molecular Imaging May Improve the Staging and Treatment of Pancreatic Ductal Adenocarcinoma
10. ATA Guidelines & Statements | American Thyroid Association
11. SNMMI procedure standard/EANM practice guideline for nuclear medicine evaluation and therapy of differentiated thyroid cancer
12. GUEST | SNMMI