COMPARISON OF ⁶⁸Ga-FAPI AND ¹⁸F-FDG PET/CT IN THE DIAGNOSIS OF SOLITARY FIBROUS TUMORS

 

Koroleva E.S., Tulin P.E., Urtenova A.А., Solomyany V.V., Filimonov A.V.

 

N.N. Blokhin National Medical Research Center of Oncology. Moscow, Russia.

P

urpose. To perform a comparative analysis of the diagnostic capabilities of ¹⁸F-FDG and ⁶⁸Ga-FAPI PET/CT in five patients with solitary fibrous tumor (SFT).

Materials and Methods. This study presents clinical case reports of five patients with Solitary Fibrous Tumors of soft tissue at various sites. To assess the extent of the disease, all patients underwent PET/CT with ¹⁸F-FDG and ⁶⁸Ga-FAPI.

Results. ⁶⁸Ga-FAPI PET/CT identified 37 tumor lesions with a median SUVmax of 45.19. These included primary tumors, local recurrences, and metastases to soft tissue, bone, liver, kidneys, and peritoneum. In contrast, ¹⁸F-FDG PET/CT detected only 8 of the 37 lesions (21%), with a significantly lower median SUVmax 6,24. ⁶⁸Ga-FAPI PET/CT demonstrated a significant advantage in visualizing peritoneal, bone, and parenchymal (liver, kidney) metastases, which showed no elevated ¹⁸F-FDG uptake above background levels.

Discussion. Our findings indicate superior diagnostic efficacy of PET/CT with ⁶⁸Ga-FAPI compared to ¹⁸F-FDG in staging Solitary Fibrous Tumors, as it identified a greater number of tumor lesions. This directly impacts disease staging and treatment planning. The intense fibroblast activation protein (FAP) expression in tumors, revealed by PET/CT with ⁶⁸Ga-FAPI, not only confirms the diagnostic value of this method but also opens prospects for developing theranostic approaches in the management of Solitary Fibrous Tumors.

Conclusion. PET/CT with ⁶⁸Ga-FAPI is a promising imaging modality for SFT, surpassing ¹⁸F-FDG in both sensitivity and image contrast. Its integration into routine clinical practice could significantly improve the diagnosis and management of patients with this disease. Prospective studies with larger patient cohorts are warranted to validate these findings.

 

Keywords: PET, positron emission tomography, 68Ga-FAPI, 18F-Fluorodeoxyglucose, Solitary Fibrous Tumor.

 

Corresponding author: Koroleva E.S., e-mail: Этот e-mail адрес защищен от спам-ботов, для его просмотра у Вас должен быть включен Javascript

 

For citation: Koroleva E.S., Tulin P.E., Urtenova A.А., Solomyany V.V., Filimonov A.V. Comparison of ⁶⁸GA-FAPI and ¹⁸F-FGD PET/CT in the diagnosis of solitary fibrous tumors. REJR 2025; 15(4):136-144. DOI: 10.21569/2222-7415-2025-15-4-136-144.

Received:        14.11.25                 Accepted: 18.12.25