Integrated analysis of F-FDG PET/CT improves preoperative lymph node staging for patients with invasive bladder cancer.

OBJECTIVES

Preoperative F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) is controversial to assess lymph node (LN) staging in patients with invasive bladder cancer. We proposed to use the maximum standardized uptake value (SUV) associated with axial-based LN size to improve the detection of regional LN metastasis.

METHODS

From May 2015 to May 2017, we prospectively included patients with urothelial bladder cancer who underwent radical cystectomy with extended pelvic LN dissection. All patients underwent preoperative F-FDG PET/CT staging before surgery. The gold standard comparator was the pathological examination of resected LNs. The data were reported on a regional per area- and patient-based model according to SUV values and axial-based LN size criteria.

RESULTS

In total, 1012 LNs were identified in 61 patients with clinically localized invasive bladder cancer who underwent radical cystectomy and extended pelvic LN dissection. Loco-regional involvement of 24 LN areas was confirmed in 17 patients. In per area analysis, diagnostic accuracy of PET/CT and CT alone were respectively 84% and 78% (p = 0.039). On patient-based analysis, combined PET/CT correctly classified pelvic LN status in 5/61 (+ 8%) additional patients using optimal thresholds compared to CT alone, with accuracies of 82% and 74%, respectively (p = 0.13).

CONCLUSION

Combining SUV and axial-based LN size criteria using F-FDG PET/CT improved the diagnostic accuracy for preoperative LN staging in patients with invasive bladder cancer, in per area analysis.

KEY POINTS

• Combining metabolical and morphological features usingF-FDG PET/CT improves the detection of malignant lymph node in patients with bladder cancer. • F-FDG PET/CT may help for initial staging of patients with muscle invasive bladder cancer.