Akademik Veri Yönetim Sistemi
European journal of nuclear medicine and molecular imaging, 2026 (SCI-Expanded, Scopus)
Objective: This study aimed to evaluate the diagnostic value of [⁶⁸Ga]Ga-FAPI PET compared with [¹⁸F]FDG PET in patients with sarcoma. Materials and methods: Thirty patients with histologically confirmed sarcoma who had previously undergone [¹⁸F]FDG PET imaging were prospectively enrolled and subsequently imaged with [⁶⁸Ga]Ga-FAPI-04 PET. [⁶⁸Ga]Ga-FAPI PET and [¹⁸F]FDG PET scans were visually assessed by three independent readers for the presence and anatomical distribution of lesions. In addition, both modalities were compared semi-quantitatively in terms of uptake intensity. Biopsy and follow-up imaging served as the reference standard. Sensitivity, specificity, positive predictive value (PPV), and accuracy were calculated on both lesion-based and patient-based analyses. Results: On a lesion-based analysis, [⁶⁸Ga]Ga-FAPI PET detected a greater number of true-positive lesions than [¹⁸F]FDG PET (149 vs. 118), demonstrating significantly higher overall sensitivity (74.5% vs. 59.0%, p < 0.001) and accuracy (71.0% vs. 58.7%, p < 0.001), particularly for bone (77.8% vs. 53.3%, p < 0.005) and lung metastases (61.6% vs. 31.4%, p < 0.001). Although specificity was slightly higher with [¹⁸F]FDG PET, the difference between the two modalities was not statistically significant (57.1% vs. 54.8%, p > 0.001). On a patient-based analysis, both imaging techniques showed similarly high sensitivity (93.1% vs. 100%), PPV (96.4% vs. 96.7%), and accuracy (90% vs. 96.7%). Quantitatively, [⁶⁸Ga]Ga-FAPI PET yielded significantly higher values for mean SUVmax, tumor SUVmax, SUVmean, SULpeak, as well as tumor-to-background ratios (TBR) in both liver and blood pool compared with [¹⁸F]FDG PET. When stratified by tumor grade (low, high, or indeterminate), SUVmax values were consistently higher with [⁶⁸Ga]Ga-FAPI PET than with [¹⁸F]FDG PET, most notably in low-grade sarcomas, although the difference did not reach statistical significance. Inter-reader agreement for [⁶⁸Ga]Ga-FAPI PET interpretation was excellent. Conclusion: [⁶⁸Ga]Ga-FAPI PET demonstrated higher sensitivity than [¹⁸F]FDG PET in sarcoma patients. Intense FAPI uptake was observed not only in low-grade sarcomas, where [¹⁸F]FDG PET is known to have relatively limited sensitivity, but also in high-grade sarcomas. These findings suggest that [⁶⁸Ga]Ga-FAPI PET may serve as a valuable diagnostic tool and holds promise as a theranostic approach in the management of sarcoma.