ABSTRACT
Objective:To prepare 68Ga-fibroblast activation protein inhibitor (FAPI)-04, and evaluate its biodistribution and imaging characteristics in animals and healthy volunteers, in order to investigate the clinical translation potential. Methods:68Ga-FAPI-04 was synthesized by a manual method and its radiolabeling yield, radiochemical purity, and stability ( in vivo and in vitro) were analyzed. ICR mice ( n=16) were scarified at 5, 30, 60 and 120 min postinjection of 68Ga-FAPI-04 (1.11 MBq) to measure radioactive counts in main organs. The dynamic mircoPET imaging was acquired for 60 min on 3 ICR mice, and tumor imaging capabilities were examined with nude mice bearing HepG2 tumors. Furthermore, 2 healthy volunteers (1 male with age of 64 years, 1 female with age of 56 years) were recruited for the investigation of probe biodistribution in humans. A serial whole-body dynamic PET/CT scan was performed immediately following injection. Results:68Ga-FAPI-04 was synthesized within 20 min with the radiochemical yield of (68.7±4.0)% (decay corrected). The radiochemical purities of 68Ga-FAPI-04 were over 99% and the products were stable for 180 min in vitro and for 90 min in blood. 68Ga-FAPI-04 was mainly cleared through urinary tracts, while other organs only showed mild tracer accumulation. MicroPET imaging showed high uptake of 68Ga-FAPI-04 in the tumor tissue of mice, and the ratio of tumor/liver was 2.14±0.01 (35 min). The PET/CT imaging results of healthy volunteers revealed 68Ga-FAPI-04 could be quickly cleared. Conclusion:68Ga-FAPI-04 has many advantages for PET imaging, such as easy labeling, good stability, quick clearance and low background signals in the liver, which can be used as an attractive PET tracer for detection hepatocellular carcinoma.
ABSTRACT
Objective To compare the application of ultrasound and positron emission tomography/computed tomography (PET/CT) in diagnosis and lymph node staging of breast cancer. Methods Using automated breast volume scanner (ABVS) and PET/CT examination of 40 lesions in 38 patients, and for comparison with the pathological findings, the diagnostic accuracy of PET/CT and ABVS in breast cancer was comparatively analyzed. Results The sensitivity of ABVS in the diagnosis of breast cancer was 95.65%, the specificity was 70.59%, and the accuracy rate was 85.00%; the sensitivity of PET/CT in the diagnosis of breast cancer was 86.96%, the specificity was 82.35%, and the accuracy rate was 85.00%;the diagnostic sensitivity of their combined application was 86.96%, the specificity was 94.12%, and the accuracy rate was 90.00%. In 10 cases of breast cancer patients with lymph node metastasis, the sensitivity、specificity and accuracy rate of PET/CT in the diagnosis of metastatic lymph nodes were 90.0%, 92.8%, and 92.1% respectively; the sensitivity, specificity and accuracy rate of ultrasound in the diagnosis of metastatic lymph nodes were 70.0%, 96.4% and 89.5%, respectively. Conclusions The ABVS and PET/CT are both effective approaches in the diagnosis of breast cancer. Their combined application may significantly improve the specificity and accuracy of diagnosis. For patients with lymph node metastases, the sensitivity of PET/CT for lymph node metastases was high and conducive to clinical staging, which is an important implication in guiding the choice of clinical treatment and prognosis of patients.