False-Negative 68Ga-FAPI PET/CT in Pediatric Thyroid Medullary Carcinoma Seen With 68Ga-DOTATOC PET/CT and 18F-FDG PET/CT

Mohamad B Haidar; Farah A Abou Zeid; Zarouhie Z Meguerian; Akram N Al-Ibraheem; Peter E Noun

doi:10.1097/RLU.0000000000005259

False-Negative 68Ga-FAPI PET/CT in Pediatric Thyroid Medullary Carcinoma Seen With 68Ga-DOTATOC PET/CT and 18F-FDG PET/CT

Clin Nucl Med. 2024 May 8. doi: 10.1097/RLU.0000000000005259. Online ahead of print.

Authors

Mohamad B Haidar¹, Farah A Abou Zeid¹, Zarouhie Z Meguerian², Akram N Al-Ibraheem³, Peter E Noun⁴

Affiliations

¹ From the Department of Diagnostic Radiology, American University of Beirut, Beirut, Lebanon.
² Department of Pathology, Saint George, Hospital University Medical Center, Beirut, Lebanon.
³ Department of Nuclear Medicine and PET/CT, King Hussein Cancer Center, Amman, Jordan.
⁴ Department of Pediatrics, Hematology Oncology, Saint George, Hospital University Medical Center, Beirut, Lebanon.

PMID: 38717245
DOI: 10.1097/RLU.0000000000005259

Abstract

In adults, 68Ga-FAP inhibitor (68Ga-FAPI) PET/CT outperforms 68Ga-radiolabeled somatostatin analog peptides (68Ga PET/CT) and 18F-FDG PET/CT in detecting thyroid lesions. This is the case of a 13-year-old boy newly diagnosed with medullary thyroid cancer with high calcitonin level. 68Ga PET/CT revealed the presence of only a primary thyroid lesion. Proven to be superior in detecting metastasis, 68Ga-FAPI PET/CT was performed. The results came out negative for primary and potential metastatic lesions. This case sheds shed light on false-negatives reported in 68Ga-FAPI PET/CT scans in pediatric patients, emphasizing the need for alternate radiotracers when a negative study is met.