Efficiency of [ 18 F]FDG PET in characterising renal cancer and detecting distant metastases: a comparison with CT

Abstract

The purpose of this study was to assess the efficiency of fluorine-18 fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) in the characterisation and primary staging of suspicious renal masses, in comparison with computed tomography, the current standard imaging modality. Fifty-three FDG PET studies were performed within the framework of a prospective study: 35 for both characterisation and staging of a suspicious mass, and 18 for staging early after surgical removal of a renal cancer. In the characterisation of renal masses, a high rate of false negative results was observed, leading to a sensitivity, specificity and accuracy of 47%, 80% and 51% respectively, versus 97%, 0/5 and 83% respectively for CT. FDG PET detected all the sites of distant metastasis revealed by CT, as well as eight additional metastatic sites, leading to an accuracy of 94% versus 89% for CT. However, 36/53 patients (68%) did not have any distant metastasis on either CT or on PET. All but one of these patients had a low Fuhrman histological grade and a limited local stage (< or =pT2). We conclude that FDG PET does not offer any advantage over CT for the characterisation of renal masses but that it appears to be an efficient tool for the detection of distant metastasis in renal cancer. However, our data suggest that a selection process could be implemented to determine which patients should undergo PET. FDG PET could be performed in the event of a solitary metastasis or doubtful images on CT. Selection could also be based on adverse histological findings from nephrectomy specimens in order to perform staging early after nephrectomy.

Comparison of 18F-FDG PET/CT and ceCT Results in the Assessment of RCC Recurrence

“…The accuracy of 18 F-FDG PET/CT in detecting distant metastasis was 94%, while the accuracy of ceCT was 89%. They emphasized that 18 F-FDG PET is especially needed for metabolic characterization if there is a solitary suspected lesion in a local advanced case [10]. In our study, although a detailed analysis of disease stage was not possible in all patients, 3 patients with distant metastasis had extensive lymphovascular invasion reported in the nephrectomy material.…”

“…The data reported by Aide et al, revealed that 18 F-FDG PET/ CT is an effective method for evaluation of distant metastasis in the early postoperative staging of RCC [10]. The accuracy of 18 F-FDG PET/CT in detecting distant metastasis was 94%, while the accuracy of ceCT was 89%.…”

“…18 for the primary diagnosis of RCC, because of urinary excretion of the radioisotope [7][8][9][10][11][12]. However, it seems to be more effective in the detection of distant metastases [8,10]. The patients were allowed to breathe normally during the procedure.…”

Radiologic Imaging of Renal Masses

“…Previous studies also noted that oncocytomas can yield false positive results on F-18 FDG-PET/CT [21,41]. [180,181] In a study by Goldberg et al [182], patients with indeterminate renal cysts were examined and F-18 FDG-PET/CT accurately detected 10 cysts as benign with no false positive results.…”

Metastatic renal cell cancer

“…FDG is excreted by the kidney, which may mask pathologic uptake. In a prospective study, Aide et al [31] found a high rate of false-negative results when localized RCC was considered (Fig. 4).…”