Abstract:
Objective To evaluate the clinical diagnostic value and optimum delay time of 18F-fluorodeoxyglucose (FDG) PET/CT delayed imaging after diuresis in prostate cancer (PCa).
Methods The clinical data of 235 male patients with prostate diseases who underwent 18F-FDG PET/CT whole-body imaging at the Characteristic Medical Center of the Chinese People's Armed Police Force from March 2009 to December 2018, including 77 patients with malignant prostate diseases and 158 patients with benign prostate diseases were retrospectively analyzed, aged 50–87(69.6±13.6) years old. All patients underwent delayed imaging before and after diuresis(1, 2, 3, and 4 h) to obtain the maximum standardized uptake value (SUVmax) of lesions before and after diuresis. SUVmax>2.5 after diuresis and a retention index>15% of SUVmax before and after diuresis were used as the criteria to judge as benign or malignant. Independent sample t-test was used to compare the data between the two groups in accordance with normal distribution.
Results The SUVmax of patients with prostate malignant lesions delayed 1, 2, and 3 h imaging after diuresis was significantly higher than that before diuresis (5.57±1.58 vs. 4.32±1.01, 7.04±3.03 vs. 4.62±1.84, 7.28±2.90 vs. 4.73±1.8; t=3.399, 3.676, 2.660; all P<0.05). No significant difference in SUVmax existed between prediuretic and delayed 4 h imaging after diuresis (t=1.103, P=0.286). In patients with benign prostate diseases, no significant difference existed in SUVmax delayed 1, 2, 3, and 4 h imaging after diuresis compared with that before diuresis (t=0.268–0.865, all P>0.05). The SUVmax of malignant lesions delayed 1, 2, and 3 h imaging after diuresis was higher than that in benign lesions (t=2.013, 3.910, 3.554; all P<0.05). However, no significant difference in SUVmax delayed 4 h imaging existed between the two groups (t=1.379, P=0.181). The SUVmax of patients with malignant lesions delayed 2 and 3 h was higher than that for diuretic imaging delayed 1 h (t=2.220, 2.400; both P<0.05). Diagnostic efficiency of 18F-FDG PET/CT delayed imaging (1, 2, 3, and 4 h) after diuresis in Pca, the specificity (74.5%, 38/51) and accuracy (76.3%, 61/80) of 2 h delayed imaging were the highest, while the sensitivity (84.6%, 11/13) of 3 h delayed imaging was the highest.
Conclusions Delayed imaging after diuresis can improve the imaging effect and clinical diagnostic efficacy of PCa patients. The diagnostic effect of delayed imaging after diuresis for 2 h was better.