To evaluate the accuracy of 11C-acetate Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) in bladder cancer (BC) staging and monitoring response to neoadjuvant chemotherapy (NAC).
Eighteen patients were prospectively enrolled. Fifteen treatment naive patients underwent 11C-acetate PET/MRI before transurethral resection of bladder tumor (TUR-BT) for primary tumor evaluation. Five patients with muscle invasive BC were imaged after NAC and prior to radical cystectomy (RC) with extended pelvic lymph node dissection (ePLND) for NAC treatment response evaluation. Two patients were part of both cohorts. 11C-acetate PET/MRI findings were correlated with histopathology. Accuracy for lymph node detection was evaluated on patient and the ePLND template (10 regions) levels.
The sensitivity, specificity and accuracy of 11C-acetate PET/MRI for the detection of muscle invasive BC was 1.00, 0.69 and 0.73 while the area under the receiver operating characteristic curve (95% confidence interval) was 0.85 (0.55-1.0), respectively. All five NAC patients underwent chemotherapy as planned and 11C-acetate PET/MRI correctly staged three patients, overstaged one and understaged one patient compared with RC and ePLND findings. A total of 175 lymph node were removed, median of 35 (range, 27-43) per patient in five patients who had RC and ePLND while 12 (7%) harboured metastases. Sensitivity, specificity, accuracy and AUC for N-staging were 0.20, 0.96, 0.80 and 0.58 on the ePLND template (10 regions) level.
11C-acetate PET/MRI is feasible for staging of BC although sensitivity for the detection of nodal metastases is low. Monitoring response to NAC shows promise and warrants evaluation in larger studies.
ClinicalTrials.gov Identifier: NCT01918592 , registered August 8 2013.
Cancer imaging : the official publication of the International Cancer Imaging Society. 2018 Aug 02*** epublish ***
Antti Salminen, Ivan Jambor, Harri Merisaari, Otto Ettala, Johanna Virtanen, Ilmari Koskinen, Erik Veskimae, Jukka Sairanen, Pekka Taimen, Jukka Kemppainen, Heikki Minn, Peter J Boström
Department of Urology, University of Turku and Turku University hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland. ., Department of Radiology, University of Turku and Turku University Hospital, Turku, Finland., Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, USA., Department of Urology, University of Turku and Turku University hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland., Department of Urology, University of Helsinki and Helsinki University hospital, Helsinki, Finland., Department of Urology, University of Tampere and Tampere University hospital, Tampere, Finland., Department of Pathology, Institute of Biomedicine, University of Turku and Turku University hospital, Turku, Finland., Department of Clinical Physiology and nuclear imaging, University of Turku and Turku University hospital, Turku, Finland., Department of Oncology and Radiotherapy, University of Turku and Turku University hospital, Turku, Finland.