PET Scan

Previous studies have shown that compared with conventional 18F-FDG PET/CT, 68Ga-FAPI PET/CT has the characteristics of not being affected by blood glucose, good tumor specificity, and high tumor-to-background ratio, and studies have shown that 68Ga- FAPI PET/CT can detect parts of breast cancer primary lesions and lymph node metastases with low 18F-FDG uptake, thereby increasing the lesion detection rate and improving the sensitivity of imaging examinations. Therefore, 68Ga-FAPI PET/CT may be used as a new effective methods for evaluating axillary lymph node efficacy after neoadjuvant treatment for breast cancer. Therefore, we plan to conduct this study to explore the ability of 68Ga-FAPI PET/CT to detect residual disease in axillary lymph nodes in patients with clinically positive axillary node (cN+) breast cancer after neoadjuvant treatment. By this way, we may explore an accurate and non-invasive assessment of axillary lymph node status after neoadjuvant therapy in breast cancer patients.

Carbonic anhydrase IX (CAIX) is a transmembrane protein which is highly expressed in approximately 95% of clear cell renal cell carcinomas, and it is closely related to tumor progression, patients prognosis and treatment response. Here, we developed a CAIX specific small molecule probe 68Ga-C1, which has shown a good diagnostic accuracy in PET/CT imaging in our preclinical mouse model of clear cell renal cell carcinoma. This enables high-contrast imaging of clear cell renal carcinoma, providing a new imaging method for the precise diagnosis of clear cell renal carcinoma. In this clinical trail, we will compare the diagnostic value of 68Ga-C1 PET/CT and 18F-FDG PET/CT in Chinese patients with indeterminate renal masses or confirmed clear cell renal cell carcinoma.

The morbidity and mortality of malignant tumors are increasing. It is one of the major diseases that affect human health. At present, the conventional imaging diagnosis methods of a variety of malignant tumors are mainly CT and MRI based on anatomical imaging. Different from traditional imaging methods to visually display the lesion, nuclear medicine molecular imaging can not only locate the tumor location, but also image the expression and activity of specific molecules and biological processes. This molecular imaging method integrating anatomy and function is a noninvasive imaging to realize the early diagnosis and differential diagnosis, curative effect evaluation and follow-up observation of a variety of tumors. Positron emission tomography/computed tomography (PET/CT) uses specific molecular probes to target tumor. It can provide detailed information about the biochemical changes of tumor tissues at the cellular and molecular levels. It has better sensitivity and specificity than conventional imaging methods. At present, the most commonly used imaging agent in clinic is 18F-fluorodeoxyglucose (18F-FDG). 18F-FDG PET/CT is a valuable imaging modality in the management of patients with malignant tumors, but it is not a specific imaging agent for tumor application. The physiological uptake of gastrointestinal tract, infected tissues, or inflammatory cells can cause high 18F-FDG uptake resulting in a significant increase of the false positive rate; in addition, some tumors including well-differentiated hepatocellular carcinoma, renal cell carcinoma, and gastric signet ring cell carcinoma have low 18F-FDG uptake resulting in a high false negative rate. Therefore, it is very important to develop new molecular probes for targeting tumor. Fibroblast-activation protein (FAP) is a type Ⅱ transmembrane serine protease and is overexpressed in cancer-associated fibroblasts (CAFs). CAFs are the predominant component in the stroma of epithelial neoplasms. FAP can be detected in various of malignant neoplasms and is associated to tumor cell migration, invasion, and angiogenesis. Recently, a novel molecular probe, gallium 68-labelled FAP inhibitor (68Ga-FAPI), has been developed and used for visualization of tumor stroma by targeting FAP. Recent studies show favorable diagnosis efficiency in a variety of tumors, especially in gastrointestinal cancer, but the previous studies were all small-sample data or case reports. Therefore, further large-size research is necessary to confirm the advantages of 68Ga-FAPI in various of malignant tumors.

As a new dual receptor (SSTR2 and FAP) targeting PET radiotracer, 68Ga-FAPI-LM3 is promising as an excellent imaging agent applicable to SSTR2 positive diseases In this research, we investigate the safety, biodistribution and radiation dosimetry of 68Ga-FAPI-LM3 in healthy volunteers. Moreover, subjects with SSTR2 positive diseases underwent contemporaneous 68Ga-FAPI-LM3 and 18F-FDG PET/CT for diseases assessment. Lesions uptakes were quantified by the maximum standard uptake value (SUVmax). The numbers of positive lesions of 18F-FDG and 68Ga-FAPI-LM3 PET/CT were recorded by visual interpretation. The diagnostic accuracy of 68Ga-FAPI-LM3 were calculated and compared to 18F-FDG PET/CT.

Currently, there are limited methods available in clinical practice to distinguish pseudoprogression after immunotherapy. Most patients rely on follow-up observations to monitor the disease, which does not meet clinical needs. 68Ga-grazytracer is a novel imaging agent targeting granzyme B. By detecting the concentration of granzyme B, it reflects the localization of cytotoxic T cells in the tumor region and their potential ability to kill tumor cells. This study aims to leverage the simplicity, non-invasiveness, visualization, and semi-quantitative advantages of 68Ga-grazytracer PET imaging to evaluate its effectiveness and feasibility in diagnosing pseudoprogression.

As a new trophoblast cell-surface antigen 2 (Trop-2) targeting PET radiotracer, 68Ga-MY6349 is promising as an excellent imaging agent applicable to various cancers. In this research, subjects with various types of tumors underwent contemporaneous 68Ga-MY6349 and standard-of-care imaging (18F-FDG) either for an initial assessment or for recurrence detection. Tumor uptake was quantified by the maximum standard uptake value (SUVmax). The numbers of positive tumor lesions of standard-of-care imaging and 68Ga-MY6349 PET/CT were recorded by visual interpretation. The diagnostic accuracy of 68Ga-MY6349 was calculated and compared to standard-of-care imaging.

As a new dual receptor (PSMA and FAP) targeting PET radiotracer, 68Ga-PSFA is promising as an excellent imaging agent applicable to PSMA/FAP positive diseases. In this research, we investigate the safety, biodistribution and potential usefulness of 68Ga-PSFA positron emission tomography (PET) for the diagnosis of lesions in PSMA/FAP positive diseases.

The primary research purpose is to evaluate the diagnostic efficacy of 68Ga-PSMA PET in metastatic lesions of locally advanced and advanced renal cell carcinoma, and to compare with that of enhanced CT. The second purpose is to evaluate whether 68Ga-PSMA PET can change the treatment decision of patients with locally advanced and advanced renal cell carcinoma

Conventional 18F-FDG PET/CT has important diagnostic value in cell metabolism level, early metastasis, judging malignant potential and prognosis of tumors. It has been routinely used for staging and restaging of most tumors, but there are still some tumors with low uptake of 18F-FDG PET/CT. Receptor imaging with a single target also has some limitations in clinical application. For example, not all diseased cells express a large amount of single receptor on the surface, which greatly affects the judgment of the nature of the lesion. The dual-target molecular imaging based on GRPr expressed in the lesion site and integrin αvβ3 receptor highly expressed on the surface of the lesion neovascularization will overcome the above limitations and make full use of the advantages of the dual-target molecular imaging, which will greatly assist the diagnosis of malignant tumors such as breast\\brain\\prostate tumor which have high GRPr and αvβ3 receptor expression . In this study, a novel dual-target imaging agent 68Ga-RM26-RGD was used for PET/CT imaging of breast\\brain\\prostate cancer, compared with conventional 18F-FDG, or single target imaging agent 68Ga-RGD or 68Ga-RM26 PET/CT imaging.

Surgery remains the only curative option for MTC, yet the current imaging-based method (ultrasound, CT, MRI, 18F-FDG PET/CT) or calcitonin-based method are insufficient to map the extent of disease. In the previous studies, TCR-FAPI can covalently bind to FAP that increase tumor uptake and tumor retention, and better diagnosed MTC than the current radiotracers. This is a phase II clinical trial to evaluate the capability of 68Ga-labeled targeted covalent radiopharmaceutical (TCR) fibroblast activation protein inhibitor (FAPI) PET/CT to guide the surgical treatment of medullary thyroid carcinoma (MTC). The surgical extent of MTC is determined based on the lesion range revealed by 68Ga-TCR-FAPI PET/CT, and the principles of surgery remains the same with differentiated thyroid carcinoma (i.e., lymph node dissection of level II-IV is required if lateral neck lymph node is considered metastasis). The primary endpoint of the study is 1-month post-surgical calcitonin level, and the secondary endpoints include the 2-year event free survival (EFS), the ratio of patient that change surgical plan, and the accuracy, sensitivity, specificity of 68Ga-TCR-FAPI PET/CT in identifying MTC lesions. Patient will be divided into three arms: 1) newly diagnosed MTC and all 68Ga-TCR-FAPI PET/CT avid lesions are resected; 2) recurrent/persistent MTC and all 68Ga-TCR-FAPI PET/CT avid lesions are resected; 3) distant metastasis or unresectable lesions shown by 68Ga-TCR-FAPI PET/CT imaging but still recommended for surgical treatment. The three arms will not be compared between each other but will be separately analyzed.