Comparing fluorodeoxyglucose positron emission tomography with computed tomography in staging for nodal and distant metastasis in urothelial/bladder cancer

Mohammed Al-Zubaidi; Katherine Ong; Pravin Viswambaram; Haider Bangash; Glenn Boardman; Steve P McCombie; Oliver Oey; Nicole Swarbrick; Andrew Redfern; Jeremy Ong; Richard Gauci; Ronny Low; Dickon Hayne

doi:10.1002/bco2.304

Comparing fluorodeoxyglucose positron emission tomography with computed tomography in staging for nodal and distant metastasis in urothelial/bladder cancer

BJUI Compass. 2024 Feb 20;5(4):473-479. doi: 10.1002/bco2.304. eCollection 2024 Apr.

Authors

Mohammed Al-Zubaidi^{1

2}, Katherine Ong¹, Pravin Viswambaram^{1

2}, Haider Bangash¹, Glenn Boardman³, Steve P McCombie^{1

2}, Oliver Oey², Nicole Swarbrick⁴, Andrew Redfern⁵, Jeremy Ong⁶, Richard Gauci⁶, Ronny Low⁷, Dickon Hayne^{1

2}

Affiliations

¹ Department of Urology Fiona Stanley Hospital Murdoch Australia.
² UWA Medical School University of Western Australia Crawley Australia.
³ Research Support and Development Unit Fiona Stanley Hospital Murdoch Australia.
⁴ Pathwest Fiona Stanley Hospital Murdoch Australia.
⁵ Department of Medical Oncology Fiona Stanley Hospital Murdoch Australia.
⁶ Department of Nuclear Medicine Fiona Stanley Hospital Murdoch Australia.
⁷ Department of Radiology Fiona Stanley Hospital Murdoch Australia.

Abstract

Objectives: We aim to assess the clinical value of ¹⁸F-fluorodeoxyglucose positron (¹⁸F-FDG-PET) scan in detecting nodal and distant metastasis compared with computed tomography (CT) scan in patients with urothelial carcinoma or bladder cancer, aiming to improve staging accuracy and thereby better prognosticate and determine therapy.

Methods: A retrospective review of 75 patients with invasive bladder cancer (≥T1) who were staged with both CT and ¹⁸F-FDG-PET within an 8-week interval was performed for the period between 2015 and 2020. Seventy-two per cent (54/75) had formal pelvic lymph node (LN) dissection or biopsy of lesions suspicious for metastases. FDG-PET definitions for positive sites were assessed depending on SUV Max (nodes with SUVmax >4 at any size, SUV > 2 for lymph nodes >8 mm, or any SUV if the lymph node was >10 mm on axial images). For CT scanning, enlarged LN by RECIST 1.1 criteria (>10 mm) as well as qualitative findings suggesting metastasis were considered positive. The analysis was based on the comparison of CT and ¹⁸F-FDG-PET findings to histopathology results from LN dissection or biopsies.

Results: Sensitivity, specificity, positive predictive values (PPV) and negative predictive value (NPV) of CT versus FDG-PET for detecting metastasis, in patients who underwent pelvic LN dissection or biopsy of lesions suspicious of metastases, were 46.6% (95% CI: 21%-70%) versus 60% (95% CI: 32%-84%), 100% (95% CI: 91%-100%) versus 83.78% (95% CI: 69%-94%), 100% (95% CI: 63%-100%) versus 60% (95% CI: 32%-84%), and 82.2% (95% CI: 68%-92%) versus 83.78% (95% CI: 69%-94%), respectively. 7/75 (9.3%) patients avoided cystectomy due to ¹⁸F-FDG-PET features of metastases that were not detected by CT.

Conclusion: FDG-PET may be more sensitive than CT for metastases in the staging of bladder cancer, which resulted in significant avoidance of aggressive local management in cases with occult metastasis.

Keywords: CT scan; FDG‐PET; bladder cancer; metastasis; neoadjuvant chemotherapy; radical cystectomy; urothelial carcinoma.