| Objective:Fibroblast cell activation protein has become an emerging target for tumor diagnosis,and various radiotracers based on fibroblast cell activation protein inhibitors have been developed and applied in the clinical detection of tumors.However,the FAPI tracers used for SPECT are rarely reported in clinical imaging.The tracers used in SPECT is made easily and cheap,and SPECT is more common.Therefore,we developed HFAPI,which was used and prepared as a 99mTc labeling kit for clinical evaluation and application.Therefore,through the experimental study using 99mTc-HFAPI in Patients with breast lesions,the in vivo biological distribution characteristics and safety analysis were obtained.On this basis,compared with 18F-FDG PET/CT imaging,to explore the diagnostic value of 99mTc-HFAPI SPECT/CT imaging in breast cancer and axillary lymph node metastasis.Materials and Methods:[99mTc]sodium acid injection was added to the HFAPI lyophilized reagent box to prepare 99mTc-HFAPI.The quality control of the new imaging molecular probe was analyzed by ITLC and HPLC.Patients with breast lesions stratified as BI-RADS 4b-5 by ultrasound and with scheduled undergo breast surgery or puncture were recruited from 2020-9 to 2022-9.Each subject signed a written informed consent form before performing 99mTc-HFAPI SPECT/CT imaging.Inclusion criteria:1)all patients were initially detected and diagnosed with breast lesions,without surgery,radiotherapy or chemotherapy;2)ultrasound grade BI-RADS 4b-5;Exclusion criteria:1)patients with liver and renal insufficiency;2)patients in pregnancy or lactation;3)patients with clinical diagnosis of wound healing,arthritis or cirrhosis.Finally,10 subjects were included in this study.The injection dose of 99mTc-HFAPI was 11.1 MBq per kilogram.Whole body planar scans and Chest SPECT/CT were initiated 60 min post injection,assessment and outline the organs of interest were used to explore the biological distribution of 99mTc-HFAPI.The various vital signs and clinical test results were observed before and after the injection.On this basis,the pathological diagnosis was used as the gold standard,compared with 18F-FDG PET/CT imaging,to explore the diagnostic value of 99mTc-HFAPI SPECT/CT imaging in breast cancer and axillary lymph node metastasis.Results:The 99mTc-labeling procedure was completed within 20 min with an overall yield of>98%.The 10 patients with breast lesions did not show significant discomfort.The biological distribution showed that the liver,gallbladder,kidney,bladder,and biliary tract showed high uptake,a small physiological uptake of salivary glands and thyroid gland,and other organs showed low uptake.Finally,10 patients with breast lesions were confirmed by pathology.Eight patients with malignant breast cancer and one patients with fibroadenoma and one was breast adenosis with fibroadenomatoid hyperplasia.In eight patients with malignant breast cancer,has sixteen axillary lymph node metastases,none of them had a distant organ metastases.All eight patients with malignant breast cancer showed a high radioactive distribution at the primary lesion,one patient with breast fibroadenoma also showed a high radioactive distribution,and one patient with fibroadenomatoid hyperplasia showed did not significant uptake 99mTc-HFAPI.99m Tc-HFAPI SPECT/CT detected all axillary lymph node metastases.Conclusion:99mTc-HFAPI can be prepared conveniently for clinical using.As a new radioactive molecular probe,HFAPI is safe and feasible for clinical application.Preliminary study in breast indicates 99mTc-HFAPI has a high detection sensitivity for primary,but also is comparable to the 18F-FDG PET/CT in the detection of distant lymph node metastases. |
