The Added-value of Staging F-FDG PET/CT in the Prediction of Overall Survival in the Patients with Bladder Cancer.

Objectives: This retrospective study aimed to evaluate the prognostic importance of F-fluorodeoxyglucose (F-FDG)-positive pelvic lymph nodes (LNs) and extra-pelvic disease on staging F-FDG positron emission tomography/computed tomography (PET/CT) in patients with bladder cancer.

Methods: Bladder cancer patients who underwent staging F-FDG PET/CT were included in the study. Histopathologic features of tumors, therapy histories, presence of distinguishable tumors on CT and PET images, sizes and maximum standardized uptake value (SUV) of primary tumors, total numbers, sizes, and SUV of F-FDG-positive pelvic and extra-pelvic LNs, and total numbers and SUV of distant metastases (M1a/1b) were recorded. Patients were followed up until death or the last medical visit. Factors predicting overall survival were determined using Cox regression analysis.

Results: Fifty-five patients [median age: 70 (53-84), 48 (87.3%) male, 7 (12.7%) female] with bladder cancer were included in this study. Twenty-nine (52.7%) patients had F-FDG positive pelvic LNs, while 24 (43.7%) patients had F-FDG positive extra-pelvic disease. Patients with F-FDGpositive pelvic LNs had a higher rate of extra-pelvic disease (p=0.003). The median follow-up duration was 13.5 months. The median overall survival was 16.3 months [95% confidence interval (CI) 8.9-23.7]. The primary tumor distinguishability on PET (p=0.011) and CT (p=0.009) images, the presence of F-FDG-positive pelvic LNs (p<0.001) and F-FDG-positive extra-pelvic disease/distant metastases (M1a/M1b) (p<0.001), and the number of distant metastases (p=0.034) were associated with mortality. The F-FDG-positive extra-pelvic disease/distant metastases [p=0.029, odds ratio: 4.15 (95% CI 1.16-14.86)] was found to be an independent predictor of mortality in patients with bladder cancer.

Conclusion: The presence of F-FDG-positive extra-pelvic disease in pretreatment F-FDG PET/CT is an important prognostic factor in bladder cancer patients.