The Value Of ¹⁸F-FCH Combined With ¹⁸F-FDG PET/CT Imaging In Hepatocellular Carcinoma

Background and ObjectiveHepatocellular carcinoma?HCC?is a common type of malignant liver tumors.Early diagnosis and accurate staging are particularly important for the treatment and prognosis of HCC patients.PET/CT could provides accurate information for staging and treatment,and ¹⁸F-FDG is the most widely used imaging agent for PET/CT.However,its sensitivity in HCC detection is relatively low.There was few studies on the application of 18F-FCH PET/CT in HCC.The purpose of this study was to investigate the value of 18F-FCH combined with 18F-FDG PET/CT in HCC.Materials and Methods?1?The subject of the present study selected 26 cases suspected HCC or recurrence of HCC from September 2016 to October 2017,all of them underwent CT or MRI examinations.All patients aged greater than 18years old,and had no previous history of cancer.There were 20 male patients and 6 female patients,aged 38-70years with an average age of 52 years.?2?All patients underwent both ¹⁸F-FDG PET/CT and ¹⁸F-FCH PET/CT imaging.The interval between the two examinations was 1-3 days,and all of them did not receive any treatment between the two examinations.All patients signed informed consent before the examinations.?3?The distribution of radioactivity lesion site compared with the surrounding normal liver tissue.Radioactive concentrated stoves are considered as"+",similar to the surrounding normal liver tissue are considered as"0",less than those surrounding normal liver tissue are considered as"-".Select the 3D region of interest?ROI?at the intrahepatic lesion to obtain the maximum normalized uptake value?SUVmax?,calculate the SUVmax lesion/SUV mean normal liver tissue to obtain the T/L value.?4?All patients had surgery or liver biopsy based on the results of PET/CT imaging after PET/CT examination.All specimens were pathologically examined by our department of pathology.All patients were followed up for 6 months.?5?Statistical analysis was performed by SPSS17.0 software.The sensitivity of¹⁸F-FCH and ¹⁸F-FDG PET/CT in different differentiation of HCC will be compared by Paired Fisher test.The differences in SUVmax,and T/L for HCCs of different degrees of differentiation will be compared by the independent sample t-test.Using the receiver operating characteristic?ROC?curves comparing the diagnostic efficacy of different pathological grade,and calculates the threshold value.The relationship between the semi-quantitative indices of the two imaging agents and the tumor diameter was compared.Semi-quantitative data were expressed as mean±standard deviation;when P<0.05,the difference was considered statistically significant.Results?1?In 26 patients,11 cases of well-differentiated HCC,9 cases of moderately differentiated HCC,6 cases of poorly differentiated HCC,confirmed by pathology.?2?The sensitivity of HCC detected by ¹⁸F-FDG PET/CT was 53.8%,compared with moderately differentiated and poorly differentiated HCC,the sensitivity to highly differentiated HCC was lower?77.8%vs18.2%and 83.3%vs18.2%,P?0.05?;When the distribution of radioactivity higher or lower than normal liver tissue are all regarded as abnormal,the sensitivity of ¹⁸F-FCH PET/CT for detecting HCC was 80.8%;the sensitivity to well-differentiated,moderately differentiated,and poorly differentiated HCC was approximately 63.6%,100%,and83.3%,respectively?P>0.05?.?3?¹⁸F-FDG imaging showed that the SUVmax and T/L of well-differentiated HCC were lower than those of moderately differentiated and poorly differentiated HCC,and the differences were statistically significant?P?0.05?.¹⁸F-FCH PET/CT imaging showed that the SUVmax and T/L of poorly differentiated HCC were lower than those of well-differentiated and moderately differentiated HCC,and the differences were statistically significant?P?0.05?.¹⁸F-FDG imaging had lower SUVmax than ¹⁸F-FCH in well-differentiated HCC?P?0.05?;¹⁸F-FDG imaging showed lower T/L in ¹⁸F-FCH than poorly differentiated HCC?P?0.05?.¹⁸F-FDG PET/CT:Using SUVmax=3.55 to distinguish well-differentiated HCC and the others,the sensitivity was 80%,and the specificity was 81.8%.Using T/L=1.38 to distinguish well-differentiated HCC and the others,The sensitivity was 73.3%,and the specificity was 81.8%.¹⁸F-FCH PET/CT imaging:Using SUVmax=6.65 to distinguish poorly differentiated HCC and the others,the sensitivity was 80.0%,and the specificity was 83.3%;Using T/L=1.12 to distinguish poorly differentiated HCC and the others.,the sensitivity was 80.0%and the specificity was 83.3%.The SUVmax and T/L values of both imaging agents were not significantly related to tumor diameter.?4?In 1/3 of the patients,additional lesions not found on the abdomen with CT or MRI were found on PET/CT scans,they were distributed in the lungs,retroperitoneum,skull,axial skeleton,and ribs,and all showed high uptake of¹⁸F-FDG and ¹⁸F-FCH,thus changed the patient's staging and treatment.All patients were followed up for 6 months.Patients with active ¹⁸F-FCH metabolism and no abnormalities in ¹⁸F-FDG metabolism showed no progress during follow-up.Patients?7/9?with reduced ¹⁸F-FCH metabolism and active ¹⁸F-FDG metabolism appear early recurrence or metastasis.Conclusion?1?¹⁸F-FCH PET/CT imaging provides a valuable method for the diagnosis of HCC,which can be a useful supplement to ¹⁸F-FDG PET/CT imaging.But still need to expand the number of cases for research.?2?Compared with poorly differentiated HCC,the uptake of ¹⁸F-FCH by well differentiated HCC appears to be higher.While ¹⁸F-FDG is the opposite;The metabolic parameters of the two imaging agents have potential application value for assessing the differentiation of HCC.?3?¹⁸F-FDG PET/CT and ¹⁸F-FCH PET/CT imaging are helpful for the staging and treatment plan of HCC patients;Choline metabolism is associated with the prognosis of HCC,and the value of choline metabolism in HCC prognosis needs to be further studied.