Differentiating renal pelvic cancer from renal cell carcinoma with 18-fluorodeoxyglucose positron emission tomography-computed tomography.

Background: The differential diagnosis of pelvis renalis cancer (PRC) from renal cell cancer (RCC) is difficult. Because of that, in this study, we compared the standardized uptake value (SUV) with positron emission tomography-computed tomography (PET-CT) of the RCC and PRC.

Methods: Twenty-one patients (12 males, 9 females; age range: 33-74 years; mean age ± standard deviation [SD]: 57.14 ± 17.6) with suspected primary renal cell cancer as Group 1 and 8 patients (6 male, 2 female; age range, 61-81; mean age ± SD, 71.5 ± 5.65) with suspected renal pelvis cancer as Group 2 detected by conventional imaging techniques (CT, magnetic resonance [MR] imaging, ultrasound, intravenous urogram, CT urography, MR urography) underwent fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT imaging between August 2010 and October 2012.

Results: Mean age is 57.14 (33-74) years in Group 1 and 71.5 (61-81) years in Group 2, respectively. The mean maximum SUV (SUV) value was 4.6 ± 2.1 in RCC group and 16.6 ± 6.9 in PRC group. At the 18-FDG PET/CT scanning, SUV value higher in patients with PRC than in the patients with RCC. It was statistically different (P < 0.001).

Conclusion: We suggested that PET/CT can be used for the differential diagnosis of renal pelvis tumor and RCC. However, further studies with larger patient number are needed to confirm our suggestion. To clarify the mechanisms of underlying these differences, molecular advanced molecular studies are needed.