TY - JOUR T1 - Assessment of dual phase 18F-FDG PET/CT with contrast-enhanced CT for evaluation of primary renal neoplasms JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1567 LP - 1567 VL - 57 IS - supplement 2 AU - ENTAO LIU AU - Tao-Tao Sun AU - Si-Yun Wang AU - Shu-Xia Wang Y1 - 2016/05/01 UR - http://jnm.snmjournals.org/content/57/supplement_2/1567.abstract N2 - 1567Objectives The aim of our retrospective study was to evaluate the efficacy of dual-phase 18F-FDG PET/CT with renal contrast-enhanced CT (CE-CT) in the detection of primary renal neoplasms.Methods Between January 2014 and December 2015, seventy-three consecutive patients (mean age:55.0±12.2 years; male/female:53/20) with renal masses were included in this retrospective study. All patients underwent whole-body (from the top of the head to the mid-thigh) 18F-FDG PET/CT (Biograph 16 HR+, Siemens, Germany) examination 1 hour after injection of 18F-FDG. Three phases (precontrast phase, corticomedullary phase, and nephrographic phase) renal CE-CT was performed after acquisition of PET and low-dose CT datasets. Furosemide was given as an intravenous injection to remove the excreted 18F-FDG from the renal pelvis. Delayed abdominal 18F-FDG PET/CT images were acquired 3 hours after injection of 18F-FDG. All patients underwent surgical resection (62/73)or biopsy (11/73)of the renal mass after imaging acquisition and the final diagnoses were based on histopathology. The maximum standardized uptake value (SUVmax) of the renal mass (SUVmax-early and SUVmax-delayed) and liver were measured. The retention index (RI) was calculated. Taking the liver uptake as reference, lesion-to-background (tumor/liver uptake, T/L) ratios were calculated. SUVmax-early, SUVmax-delayed and T/L ratios were compared between histopathological types. The sensitivity, specificity, accuracy, and negative and positive predictive values in 18F-FDG PET/CT for the early and the delayed scanning and combined contrast-enhanced renal CT were calculated.Results Of 73 renal masses, 62 were renal cell carcinoma (RCC), 6 were transitional cell carcinoma (TCC) of the renal pelvis, and 5 were angiomyolipoma (4 AML with minimal fat). In 62 RCC, 49 were clear cell RCC (ccRCC, Fuhrman grade: Grade I,5 lesions; Grade II,31 lesions; Grade III,10 lesions; Grade IV,3 lesions), 5 were chromophobe RCC, 6 were papillary RCC, and 2 were carcinoid tumor (Table 1). In 68 primary malignant tumor, 12 extra-renal metastasis lesions were detected (Table 2). Average tumor sizes were 5.52±2.70, 5.40±2.77, and 5.44±2.67. The average SUVmax-early, SUVmax-delayed, and T/L ratios was 4.40±3.11, 3.76±3.31,and 1.71±1.34, respectively. There was a statistically significant difference in average SUVmax-early, SUVmax-delayed, and T/L ratios between low grade ccRCC and high grade ccRCC (Table 3). Of 73 renal lesions, 57 were RI<0 (Table 4).Sensitivity, specificity, positive predictive value, negative predictive value,and accuracy of 18F-FDG PET/CT (mono-phase scanning) were 48.5%, 60.0%, 94.3%, 7.9% and 49.3%, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT (dual-phase scanning ) were 57.4%, 80.0%, 97.5%, 12.1% and 58.9%, respectively. Sensitivity, specificity, positive predictive value, negative predictive value,and accuracy of 18F-FDG PET/CT (mono-phase scanning with renal CE-CT) were 94.1%, 20.0%, 94.1%, 20.0% and 89.0%, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 18F-FDG PET/CT (dual-phase scanning with renal CE-CT) were 94.1%, 20.0%, 94.1%, 20.0% and 89.0%, respectively (Table 5).Conclusions 18F-FDG PET/CT with reanl CE-CT shows high diagnostic accuracy and sensitivity for the detection of the renal tumor. Renal CE-CT helps in detection faint uptake and moderate uptake renal lesions. 18F-FDG PET/CT with CE-CT has more useful than dual phase 18F-FDG PET/CT. ER -