Background: PET with 18F-FDG has been considered of limited value for the detection of bladder cancer because of the urinary excretion of the tracer. Purpose: To investigate the clinical value of dual phase 18F-FDG PET/CT with oral diuretic in the diagnosis of bladder cancer. Methods: 107 patients with suspected bladder cancer were enrolled in the present study from May

2003 to May

2012. Each patient underwent the whole body 18F-FDG PET/CT scans routinely. After that

all patients received the forced diuresis by orally administration of furosemide (40mg) and drinking a lot of water. Two hours later

after several times of urination

the patients underwent an additional delayed pelvic PET/CT scans. The intravesical radioactivity was compared between the routine and delayed the scans and the visualization of the tumor was evaluated. The diagnostic efficacy was determined based on the pathological examinations and the clinical following-up. Results: With the forced diuresis

intravesical 18F-FDG activity decreased significantly in 96.3% of the patients. The lesions on the wall of urinary bladder were visualized clearly in the delayed PET images

which weren’t seen in the routine PET images. 18F-FDG PET/CT was positive in 75 patients who all then received the operation. 69 patients were diagnosed pathologically to have the bladder cancer and 6 patients to have benign diseases. 18F-FDG PET/CT was negative in another 32 patients. Four patients of them were then diagnosed to be bladder cancer. Another 28 patients were clinically followed up more than 6 months and none of them was found to have bladder cancer. The sensitivity

specificity and accuracy of the dual phase PET/CT imaging for diagnosing the bladder cancer were 94.5%(69/73)

82.4%(28/34) and 90.7%(97/107)

respectively. Conclusion: The forced diuresis using oral furosemide can significantly reduce the intravesical radioactivity and improve the detectability of 18F-FDG PET/CT for the bladder cancer.Cited