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Objective:To investigate the clinical utility of 68Ga-labeled fibroblast activation protein inhibitor (FAPI) PET/CT in the detection of primary and metastatic gastric signet-ring cell carcinoma (GSRCC) and compared the results with those of 18F-FDG PET/CT. Methods:A total of 21 patients (10 males, 11 females, average age 52 years) with primary and metastatic GSRCC who underwent 68Ga-FAPI and 18F-FDG PET/CT at the First Affiliated Hospital of Xiamen University from June 2020 to May 2022 were retrospectively analyzed. Pathological results of surgery and (or) biopsy were used as the " gold standard" for final diagnosis. In cases whose surgery or tissue biopsies were not available, clinical and radiographic follow-up results were used as the reference standards. Wilcoxon signed-rank test was used to compare the SUV max of 18F-FDG and 68Ga-FAPI. McNemar χ2 test was used to compare the detection rate between 18F-FDG and 68Ga-FAPI PET/CT. Results:68Ga-FAPI PET/CT showed higher SUV max than 18F-FDG in primary tumors (5.3(2.4, 15.7) vs 2.4(1.8, 2.5); z=2.31, P=0.021), local recurrences (7.8(6.0, 8.9) vs 2.4(1.9, 3.4); z=2.20, P=0.028), lymph nodes metastases (7.7(4.5, 12.2) vs 2.4(1.9, 3.6); z=6.01, P<0.001) and bone/visceral metastases (6.7(5.3, 11.1) vs 2.4(2.0, 3.4); z=11.36, P<0.001). Regarding diagnostic accuracy, 68Ga-FAPI PET/CT showed higher sensitivities than 18F-FDG for primary tumors (7/9 vs 2/9; χ2=3.20, P=0.063) and local recurrences (7/7 vs 2/7; χ2=3.20, P=0.063). It also demonstrated higher lesion detection rates than 18F-FDG for suspicious lymph node metastases (86%(65/76) vs 32%(24/76); χ2=31.37, P<0.001) and bone/visceral metastases (99%(184/185) vs 39%(73/185); χ2=107.08, P<0.001). Conclusions:68Ga-FAPI PET/CT showed higher tumor uptake and lesion detection rate than 18F-FDG in the primary and metastatic GSRCC. 68Ga-FAPI PET/CT demonstrates good diagnostic performance for tumor detection, staging, and restaging of GSRCC, which is helpful to further guide clinical treatment strategy.
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Objective To investigate the value of 18F-FDG PET/CT in the phasing and grading of renal cell carcinoma (RCC) complicated with vena cava tumor thrombus (VCTT).Methods From December 2011 to September 2015,a total of 72 patients (52 males,20 females,age:36-74 years) were enrolled in this retrospectively study.All patients underwent 18F-FDG PET/CT and contrast-enhanced CT studies,and were diagnosed as RCC.The RCC patients combined with VCTT were classified by Mayo-level.Wilcoxon rank sum test was used to compare the grading of VCTT by PET/CT and contrast-enhanced CT.NM staging on abdominal area level was performed and the results were compared with x2 test.Results VCTT was identified in 18 RCC patients and the grading results by PET/CT were as follows:9 cases in Level 0,4 cases in Level Ⅰ,2 cases in Level Ⅱ,1 case in Level Ⅲ,and 2 cases in Level Ⅳ.When evaluated by PET/CT,20 cases were in N0M0,21 were in N1M0,9 were in N0M1,and 22 were in N1M1.NM staging results by contrast-enhanced CT were as follows:50 cases in N0M0,10 in N1M0,10 in N0M1,and 2 in N1M1.In addition,2 N1 and 2 M1 were found by the whole body PET/CT.The classification results of VCTT and staging of abdominal level by PET/CT were significantly better than those by contrast-enhanced CT (z=-2.462,P＜0.05;x2=32.806,P＜0.01).Conclusion 18F-FDG PET/CT is not only valuable for detecting primary RCC and local metastasis,but also useful for finding where the VCTT extends,which is conducive to therapeutic planning and further clinical treatment.
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Objective To explore the clinical value of 18F-FDG PET/CT in the diagnosis of cardiac neoplasm.Methods Between January 2007 and December 2011,18F-FDG PET/CT was performed in 8649 patients in our hospital,and 14 (0.16％ ; 11 males,3 females,average age 46.9 (35-68) years) patients were diagnosed with cardiac neoplasm.18F-FDG PET/CT data of those 14 patients were retrospectively analyzed.Final diagnoses were confirmed by either histopathology (n =5) or follow-up (n =9).Results Accurate tumor localization and diagnoses were made by 18 F-FDG PET/CT in all 14 patients.Among them,13 were malignant (2(14.3％,2/14) primary and 11(78.6％,11/14) metastatic tumors (8 HCC,2 lung cancer,1 esophageal cancer) ; SUVmax 3.2-10.7) and 1 (7.1％,1/14) was benign (myxoma).Conclusion 18F-FDG PET/CT is useful for the detection and staging of primary malignant and metastatic cardiac neoplasms.