Evaluation of role of FDG-PET/CT in staging and restaging of patients with renal cell carcinoma

In our study, we aimed to evaluate the sensitivity and specificity of 18F-FDG PET/CT in demonstration of the primary lesion, recurrences and/or metastasis, to compare of the findings in 18F-FDG PET/CT with the other conventional imaging modalities and to evaluate the relationship of the tumor with the histopathological subtypes and their degrees in patients with RCC.Patients having either prediagnosis or diagnosis of RCC who underwent 18F-FDG PET/CT examination in Nuclear Medicine Department of Gazi University Hospital, had diagnosis of RCC consequently and were clinically followed in GUFM were examined in our scope of study. Maximum SUV (SUV max) values of visually detected lesions were obtained from PET/CT data of patients. Moreover, results of routine histopathological evaluation, results of routine other conventional imaging modalities and clinical findings of patients were noted. In our study, total 43 18F-FDG PET/CT examinations of 36 patients were evaluated.In our study, we observed correct evaluation of primary mass using PET/CT in 6 patients whom we have done primary staging. We found sensitivity, specificity, PPV, NPV, accuracy ratio of PET/CT as 93%, 82%, 94%, 78% and 91%, accordingly and sensitivity, specificity, PPV, NPV, accuracy ratio of conventional imaging modalities as 90%, 42%, 85%, 53% and 79, accordingly in detecting recurrences and/or metastasis of RCC. Superiority in evaluation of primary renal mass and high diagnostic performance in evaluation of RCC recurrences and/or metastasis of PET/CT are assumed to be related to achievement of anatomical localization due to PET/CT hybrid system and fewer number of patients included in our study. No significant difference between histopathological subtypes regarding diagnostic performance of PET/CT was found, but increased diagnostic accuracy ratio of PET/CT was observed parallel to increased Fuhrman grade.As a conclusion, PET/CT is an imaging modality having high diagnostic performance without any risk of functional damage of kidneys and contrast allergy which also makes it possible to image whole body anatomically and functionally/metabolically in a single examination and to make correlations in-between the findings.