Detection of Lymph Node Metastasis in Patients with Bladder Cancer using Maximum Standardised Uptake Value and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: Results from a High-volume Centre Including Long-term Follow-up

Abstract

Background: Preoperative staging with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) combined with computed tomography (CT) is used for the evaluation of metastatic disease in patients with invasive bladder cancer. The use of quantification with maximum standardized uptake value (SUVmax) of regional lymph nodes (LNs) has been suggested to increase the diagnostic ability for detection of malignancy.

Objective: Assessment of the utility and clinical relevance of SUVmax in ¹⁸F-FDG PET in detecting regional nodal metastases in patients considered for radical cystectomy.

Design, setting, and participants: From 2011 to 2014, we identified a total of 119 patients with urothelial carcinoma who underwent radical cystectomy with extended LN dissection; additionally, 12 patients were identified by preoperative biopsy. All patients underwent ¹⁸F-FDG PET/CT before treatment recommendation. Pathological findings were compared with preoperative PET/CT staging and analysed in a regional- or patient-based model according to SUVmax values.

Outcome measurements and statistical analysis: In total, 2291 LNs were identified in 131 patients; locoregional involvement of 85 LNs were confirmed in 34 patients.

Results and limitations: SUVmax >2 analysis: sensitivity±95% confidence interval of 79.4% (62.1-91.3) and specificity 66.5% (55.7-75.3). SUVmax >4 based analysis: sensitivity was 61.8% (43.6-77.8) and specificity was 84.5% (75.8-91.1). Two years of follow-up implied that higher SUVmax is correlated with higher recurrence risk, independent of conventional pathological findings.

Conclusions: ¹⁸F-FDG PET/CT using SUVmax of LNs is a useful tool for preoperative evaluation of pelvic LN metastases from invasive bladder cancer and contributes to the selection of patients for personalized treatment.

Patient summary: In this report, we establish that it is possible to identify disease from bladder cancer in the lymphatic tissue surrounding the bladder using a scan analysis. This assists in the selection of treatment for patients with bladder cancer and may spare patients from unnecessary procedures.

Keywords: FDG-PET/CT; Fluorodeoxyglucose F18; Invasive bladder cancer; Lymph node staging; PET-CT.