PT - JOURNAL ARTICLE AU - Guanyun Wang AU - Yachao Liu AU - Jing Ning AU - Mu Lin AU - Yue Wu AU - Baixuan Xu AU - Jiangping Gao TI - <strong>To access the clinical value of combined<sup> 18</sup>F-FDG and <sup>18</sup>F-DCFPyL PET/CT in postoperative recurrent or metastasis renal cell carcinoma</strong> DP - 2020 May 01 TA - Journal of Nuclear Medicine PG - 478--478 VI - 61 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/61/supplement_1/478.short 4100 - http://jnm.snmjournals.org/content/61/supplement_1/478.full SO - J Nucl Med2020 May 01; 61 AB - 478Objectives: Positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG), although not part of the standard protocol in RCC staging, shows promise for restaging and monitoring of treatment. Many studies reported high accuracy in the follow-up or suspected local recurrence/metastatic disease of patients with RCC. Meanwhile, although PSMA refers to prostate origin, it has been found in many other types of tumors and related neovascular endothelial cells, including transitional cell carcinoma, malignant melanoma, lung cancer soft tissue sarcoma, and kidney tumors. Clinically, people are increasingly interested in the diagnosis of suspected recurrence of RCC using PSMA PET/CT, especially in terms of bone metastases. Therefore, the combination of the 18F-labeled low-molecular weight PSMA ligand 2-(3-{1-carboxy-5-[(6-[18F]fluoro-pyridine-3-car-bonyl)-amino]-pentyl}-ureido)-pentanedioic acid, commonly known as 18F-DCFPyL and 18F-FDG will help to diagnose suspected postoperative recurrent or metastasis renal cell carcinoma. By using 18F-FDG and 18F-DCFPyL PET/CT, this study aims to diagnose the patients who were suspected with renal clear cell carcinoma recurrence or metastasis after surgery for ccRCC. Materials and Methods: We retrospectively analyzed 15 consecutive patients (14 males and 1 female, mean age 58.3±11.8 years old) who were suspected with postoperative recurrent or metastasis ccRCC, and underwent18F-FDG PET/CT scans and 18F-DCFPyL PET/CT scans. 13 patients were finished 18F-FDG PET/CT scans and followed by additional 18F-DCFPyL PET/CT scans within a week,and 1 patient were followed by additional 18F-DCFPyL PET/CT scans within half year,1 patient only finished 18F-DCFPyL PET/CT scans.We reviewed PET/CT findings and compared the ability of 18F-FDG PET/CT and 18F-DCFPyL PET/CT to detect lesions in the same patients, and judged their ability to comprehensively diagnose lesions. Histopathological findings were used as the reference standard. Results: There were 58 and 63 lesions on 18F-FDG and 18F-DCFPyL PET/CT images, respectively (Table 1). Biopsies of all patients were analyzed for histopathological correlation. Pathological assessments of biopsy specimens confirmed three patients associated with local recurrence , the other 10 were associated with metastatic lesions in the lymph nodes, lungs, pancreas, soft tissues and bones, and 1 patient was a benign lesion, respectively. Two patients with FDG positive lesions were finally confirmed as postoperative changes, but 18F-DCFPyL showed better diagnostic accurracy(Table 2). The TBR value of SUVmax of the patient’s erector spinae beside the first lumbar vertebra of PSMA and FDG are 0.53±0.18 and 0.86±0.18, respectively (p&lt;0.001, Table 3). For metastatic lesions in lung, pancreas and soft tissue other than lymph nodes and bones, uptake of PSMA and FDG exhibited no significances showed (SUVmax: 6.52±6.40 vs 3.63±1.54, p=0.387, Table 4). But in bone metastatic, PSMA found more lesions (PSMA: 22 vs FDG:14) and had higher SUV than FDG(SUVmax: 6.41±3.86 vs 2.78±1.50, p&lt;0.001, Table 5). One patient was found with multiple lymph node metastasis. There were statistically significant differences in SUVmax between PSMA and FDG (3.56±1.09 vs 13.12±2.45, p&lt;0.001, Table 6). Conclusions: According to our results, 18F-DCFPyL PET/CT is better than 18F-FDG PET/CT in detecting bone metastasis and distinguishing benign and malignant lesions, but in the diagnosis of lymph node metastasis, FDG has advantages over PSMA. Our preliminary experience suggests that 18F-DCFPyL PET/CT may play a complementary role to 18F-FDG in detecting postoperative recurrent and metastasis of ccRCC. Acknowledgement: Finally, I would like to express my sincere gratitude to the anonymous reviewers for their significant contributions to the publication and improvement of my thesis.