Tumor Imaging With 68Ga-DOTA-FAPI-04 PET/CT: Comparison With 18F-FDG PET/CT in 22 Different Cancer Types.

Cancer-associated fibroblasts, which are densely found in tumor tissue, express high levels of fibroblast activation protein (FAP), and FAP inhibitors (FAPIs) labeled with radionuclides can be used in the diagnosis and treatment of cancer. In this study, the role of 68Ga-DOTA-FAPI-04 PET/CT in imaging of primary, metastatic, and recurrent cancers was investigated. A total of 42 patients (16 females, 26 males; mean age, 58.5 years; range, 31-84 years) with 22 different types of malignant diseases were included in the study. 68Ga-DOTA-FAPI-04 PET/CT imaging was performed 1 to 7 days after 18F-FDG PET/CT. Pathological uptake levels in primary tumoral lesions, lymph nodes, skeletal system, liver, peritoneal surfaces, and other body parts were compared between 2 PET/CTs. In addition, physiological uptake levels of 18F-FDG and 68Ga-FAPI were defined measuring the liver, thoracic aorta, gluteal muscle activities, and uterus activity in female patients. Of the 42 patients in the study group, 33 patients were included for staging, 8 patients for restaging, and 1 patient for evaluation of treatment response. 68Ga-DOTA-FAPI-04 PET/CT showed intense uptake in 94.2% of primary tumoral lesions. In patients with multiple myeloma, 18F-FDG uptake in the bone marrow was significantly higher than 68Ga-FAPI uptake, whereas in gastric signet ring cell tumors, 68Ga-FAPI uptake was found to be significantly higher than 18F-FDG uptake. It was observed that 68Ga-DOTA-FAPI-04 PET/CT detected bone, liver, and peritoneum metastases with higher sensitivity and accuracy compared 18F-FDG PET/CT. The preliminary findings of this study showed that 68Ga-DOTA-FAPI-04 PET/CT can contribute to the diagnostic process in solid tumors. Especially in malignancies with mild uptake on 18F-FDG PET/CT, it stands out in diagnosis, staging, and restaging. It is also predicted that FAPI molecules can be used for radionuclide therapy in patients with metastatic disease and unresponsive to other treatments showing intense uptake on 68Ga-DOTA-FAPI-04 PET/CT.

Çermik TF ，Ergül N ，Yılmaz B ，Mercanoğlu G ... -  《-》

[(68)Ga]Ga-DOTA-FAPI-04 PET/CT in the evaluation of gastric cancer: comparison with [(18)F]FDG PET/CT.

This study aimed to compare the performance of [68Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT in the evaluation of primary and metastatic lesions of gastric cancer. Fifty-six patients with histologically proven gastric carcinomas were enrolled in this study, including 45 patients for staging and 11 patients for restaging after surgery. Each patient underwent both [18F]FDG and [68Ga]Ga-DOTA-FAPI-04 PET/CT within 1 week. The activity of tracer accumulation in lesions was assessed by maximum standardized uptake value (SUVmax) and TBR (lesions SUVmax/ascending aorta SUVmean). Histological workup served as a standard of reference. If tissue diagnosis was not applicable, the follow-up data including the results of laboratory tests and medical imaging could also serve as a reference. [68Ga]Ga-DOTA-FAPI-04 PET/CT was comparable to [18F]FDG on detecting primary tumors and lymph node (LN) metastases, whereas [68Ga]Ga-DOTA-FAPI-04 outperformed [18F]FDG in detecting peritoneal (159 vs. 47, P < 0.001) and bone metastases (64 vs. 55, P = 0.003) by the lesion-based analysis. [68Ga]Ga-DOTA-FAPI-04 showed higher SUVmax (10.3 vs. 8.1, P = 0.004) and TBR (11.6 vs. 5.8, P < 0.001) in primary tumor, and higher TBR in LN involvement (8.0 vs. 3.7, P < 0.001) and peritoneal metastases (8.1 vs. 3.2, P < 0.001), compared with [18F]FDG PET/CT. The specificity and positive predictive value of [68 Ga]Ga-DOTA-FAPI-04 were significantly higher than that of [18F]FDG (100.0% vs. 97.7%, P < 0.001; 100.0% vs. 57.1%, P = 0.001) in determining the LN status. [68Ga]Ga-DOTA-FAPI-04 was comparable to [18F]FDG in evaluating N-staging (47.1% vs. 23.5%, P = 0.282). [68Ga]Ga-DOTA-FAPI-04 PET/CT detected more positive recurrent lesions in all restaging patients and showed clearer tumor delineation. Two patients underwent follow-up [68Ga]Ga-DOTA-FAPI-04 PET/CT scans after chemotherapy, which both showed remission. [68Ga]Ga-DOTA-FAPI-04 PET/CT can better evaluate primary gastric cancer and metastatic lesions in the peritoneum, abdominal LNs, and bone. Furthermore, [68Ga]Ga-DOTA-FAPI-04 PET/CT provided more information for patients with recurrent disease and had the potential in monitoring response to treatment.

Lin R ，Lin Z ，Chen Z ，Zheng S ，Zhang J ，Zang J ，Miao W ... -  《-》

The potential utility of [(68) Ga]Ga-DOTA-FAPI-04 as a novel broad-spectrum oncological and non-oncological imaging agent-comparison with [(18)F]FDG.

This study aimed to compare the detection performance of [68 Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT in the patients with various oncological and non-oncological lesions. A total of 123 patients underwent contemporaneous [68 Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT were included in this prospective study. The maximum standard uptake value (SUVmax) was measured to compare oncological and non-oncological lesion uptake. The sensitivity, specificity, predictive values, and accuracy of [18F]FDG and [68 Ga]Ga-DOTA-FAPI-04 PET/CT for detecting primary, metastatic, and non-oncological lesions were calculated and compared to evaluate the detection efficacy. The study subjects consisted of 123 patients (69 men and 54 women; mean age 56.11 ± 11.94 years). Among the 102 patients with either newly diagnosed (82 patients) or previously treated solid tumor (20 patients), a total of 88 solid primary malignant tumors in 84/102 patients were detected. Two patients had two primary tumors each and 1 patient had three primary tumors. Among them, 58/102 and 43/102 patients had nodal (376 lesions) and distant metastases (406 lesions), respectively. Eight patients had hematological neoplasm. No malignant oncological diseases were detected in the remaining 13 patients. A total of 145 non-oncological lesions and benign tumors in 52/123 patients were detected incidentally. [68 Ga]Ga-DOTA-FAPI-04 PET/CT demonstrated a significantly higher uptake and detection rate for the primary (SUVmax 10.98 ± 5.83 vs. 8.36 ± 6.43, p < 0.001; sensitivity 97.67 vs. 84.89%; and accuracy 96.59 vs. 82.95%, X2 = 0.538, p = 0.021), nodal (SUVmax 10.50 ± 5.98 vs. 8.20 ± 6.29, p = 0.011; sensitivity 97.59 vs. 84.72%; and accuracy 97.34 vs. 84.31%, X2 = 2.067, p < 0.001), and distant metastatic lesions (SUVmax 9.64 ± 6.45 vs. 6.74 ± 4.83; p < 0.001; sensitivity 98.01 vs. 65.59%; and accuracy 97.04 vs. 65.51%, X2 = 4.897, p < 0.001) of solid tumor than did [18F]FDG PET/CT. [68 Ga]Ga-DOTA-FAPI-04 PET/CT demonstrated a lower activity (SUVmax: 6.84 ± 4.67 vs. 13.09 ± 7.29, p < 0.001) and detection rate (sensitivity 50.65 vs. 96.75%, and accuracy 51.28 vs. 95.51%, X2 = 5.166, p < 0.001) for multiple myeloma and lymphoma compared to [18F]FDG PET/CT. [68 Ga]Ga-DOTA-FAPI-04 and [18F]FDG PET/CT PET/CT demonstrated a comparative activity (SUVmax 6.40 ± 3.95 vs. 5.74 ± 15.78, p = 0.729) and detection efficacy (sensitivity 86.52 vs. 72.34%, and accuracy 84.83 vs. 72.41%, X2 = 9.460, p = 0.007) for non-oncological lesion and benign tumor detection. Except for myeloma and lymphoma, [68 Ga]Ga-DOTA-FAPI-04 PET/CT showed a superior detection efficacy for detecting various primary and metastatic lesions than [18F]FDG PET/CT. A comparative detection utility for non-oncological lesion was obtained with both tracers. [68 Ga]Ga-DOTA-FAPI-04 could be used as a broad-spectrum tumor and inflammatory imaging agent in the clinical especially for various solid tumors and non-oncological lesions.

Lan L ，Liu H ，Wang Y ，Deng J ，Peng D ，Feng Y ，Wang L ，Chen Y ，Qiu L ... -  《-》

Comparison of [(68)Ga]Ga-DOTA-FAPI-04 and [(18)F] FDG PET/CT for the diagnosis of primary and metastatic lesions in patients with various types of cancer.

Chen H ，Pang Y ，Wu J ，Zhao L ，Hao B ，Wu J ，Wei J ，Wu S ，Zhao L ，Luo Z ，Lin X ，Xie C ，Sun L ，Lin Q ，Wu H ... -  《-》

Comparison of 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT in the staging and restaging of gastric adenocarcinoma.

In this study, we aimed to evaluate the diagnostic sensitivities of 68Ga-FAPI-04 PET/CT and 18F-FDG PET/CT in the primary tumor, and nodal, peritoneal and distant organ metastases of primary and recurrent gastric adenocarcinoma (GAc) with patient and lesion-based comparison. Twenty-one patients with histopathologically proven newly diagnosed or recurrent GAc who underwent 18F-FDG and 68Ga-FAPI-04 imaging were included in the study. Both imaging techniques were evaluated visually according to the intensity of organ-based uptake. SUVmax and tumor-to-background ratio (TBR) values obtained from primary tumor/relapse and metastatic organs were compared statistically. 68Ga-FAPI-04 uptake was positive in all 15 newly diagnosed patients, while two patients among them who had mucinous and signet ring cell carcinoma did not exhibit 18F-FDG uptake. The sensitivity and specificity of 68Ga-FAPI-04 PET/CT in detecting primary gastric were 100%, while the sensitivity and specificity of 18F-FDG were 86.6 and 100%, respectively. 68Ga-FAPI-04 imaging revealed diffuse stomach uptake in seven patients, while 18F-FDG could only show two of them. The sensitivity and specificity of in-patient-based detection of lymph node metastases were 100 and 95.2%, respectively, while these values were 71.4 and 93.7%, respectively, for 18F-FDG. For peritoneal involvement 68Ga-FAPI-04 had a sensitivity and specificity of 100%, whereas 18F-FDG had a sensitivity of 40% and a specificity of 100%. 68Ga-FAPI-04 PET/CT is an imaging modality with the potential of yielding more sensitive and specific findings 18F-FDG PET/CT. This modality may help avoid invasive diagnostic procedures that may be frequently required in GAc.

Gündoğan C ，Kömek H ，Can C ，Yildirim ÖA ，Kaplan İ ，Erdur E ，Poyraz K ，Güzel Y ，Oruç Z ，Çakabay B ... -  《-》