Commentary on “Outpatient laser ablation of non-muscle-invasive bladder cancer_ Is it safe, tolerable and cost-effective?” Wong KA, Zisengwe G, Athanasiou T, O׳Brien T, Thomas K, The Urology Centre, Guys and St. Thomas' NHS Foundation Trust

Objective: To evaluate the clinical impact of (18) F-fluorodeoxyglucose (FDG)-positron-emission tomography/computed tomography (PET/CT) scanning, compared with conventional staging with contrast-enhanced CT imaging (CECT). Patients and methods: The FDG-PET/CT results of 96 consecutive patients with bladder cancer were analysed. Patients included in this study underwent standard CECT imaging of the chest and abdomen/pelvis o4 weeks before FDG-PET/CT. Based on the original imaging reports and recorded tumour stage before and after FDG-PET/CT imaging, the preferred treatment strategies before FDG-PET/CT and after FDG-PET/CT were determined for each patient using an institutional multidisciplinary guideline. One of the following treatment strategies was chosen: (i) local curative treatment; (ii) neoadjuvant/induction chemotherapy; or (iii) palliation. The changes in management decisions before and after FDG-PET/CT were assessed. Results: The median (range) interval between CECT and FDG-PET/CT was 0 (029) days. In 21.9% of the patients, stage on FDG-PET/ CT and CECT were different. Upstaging by FDG-PET/CT was more frequent than downstaging (19.8 vs 2.1%). Clinical management changed for 13.5% of patients as a result of FDG-PET/CT upstaging. In eight patients, FDG-PET/CT detected second primary tumours. This led to changes of bladder cancer treatment in another four of 96 patients (4.2%). All the management changes were validated by tissue confirmation of the additional lesions. Conclusions: FDG-PET/CT provides important additional staging information, which influences the treatment of carcinoma invading bladder muscle in almost 20% of cases. Patient selection for neoadjuvant/induction chemotherapy was improved and futile attempts at curative treatment in patients found to have metastases were avoided.