Abstract
1604
Objectives The aim of our retrospective study was to assess the utility of 18F-FDG PET/CT in the re-staging of patients affected by clear cell renal cell carcinoma (RCC).
Methods 68 pts (mean age 62,8 yrs) affected by clear cell RCC after nephrectomy (TNM at staging: T1 42 pts; T2 10 pts; T3 13 pts; T4 3 pts; Fuhrman Grade: G2 42 pts, G3 24 pts; G4 2 pts) underwent 18F-FDG PET/CT due to a clinical or diagnostic suspicion of metastases. Images were interpreted visually by two experienced readers. Areas of abnormal uptake were classified, taking the liver uptake as reference, as follow: 1=faint uptake, lower than liver ; 2=moderate uptake, equal to liver; 3= high uptake, higher than liver. Validation of results was established by: 1) biopsy; 2) BS, CT or MRI; 3) subsequent 18F-FDG PET/CT.
Results PET/CT was positive in 41 pts and negative in 27 pts. On a lesion basis, positive findings were detected in: bone (11 pts), lung (8 pts), bone and lung (5 pts), lymph nodes (4 pts), bone and pleura (1 pt), lung and lymph nodes (3 pts), lymph nodes, liver and bone (1 pt), liver, lung and bone (1 pt), local relapse (2 pts), local relapse and lymph nodes (1 pt), local relapse and contralateral kidney (1 pt), contralateral kidney (1 pt), contralateral kidney and lymph nodes (2 pts). Results were confirmed by: biopsy (n=17); other imaging modalities (n=42) ; PET/CT (n=9). 40 pts resulted true positive, 1patient false positive, 17 pts true negative and 10 pts false negative. Sensitivity and specificity were 80% and 94%, respectively. Uptake of the lesions resulted faint in 4 pts, moderate in 7 pts and high in 29 pts. No correlation between size of positive findings and intensity of the uptake was found.
Conclusions PET/CT demonstrated a good sensitivity in the re-staging of clear cell RCC. Most of the lesions showed intense tracer uptake. According to our results it seems that the use of 18F-FDG PET/CT in the restaging of RCC is feasible.