Background: Current imaging criteria for categorising disease response in metastatic renal cell carcinoma (mRCC) correlate poorly with overall survival (OS) in patients on anti-angiogenic therapies.
We prospectively assess diffusion-weighted and multiphase contrast-enhanced (MCE) MR imaging (MRI) as markers of outcome.
Methods: Treatment-naive mRCC patients on a phase II trial using sunitinib completed an MRI substudy. Whole-tumour apparent diffusion coefficient (ADC) maps and histograms were generated, and mean ADC and AUClow (proportion of the tumour with ADC values lying below the 25th percentile of the ADC histogram) recorded. On MCE-MRI, regions of interest were drawn around the most avidly enhancing components to analyse enhancement parameters. Baseline (n=26) and treatment-related changes in surviving patients (n=20) were correlated with OS. Imaged metastases were also analysed.
Results: Forty-seven per cent of the patients showed significant changes in whole-tumour mean ADC following therapy, but there was no correlation with outcome. Patients with a high baseline AUClow and greater-than-median AUClow increase had reduced OS (HR=3.67 (95% confidence interval (CI)=1.23-10.9), P=0.012 and HR=3.72 (95% CI=0.98-14.21), P=0.038, respectively). There was no correlation between MCE-MRI parameters and OS. Twenty-eight metastases were analysed and showed positive correlation with primary tumour mean ADC for individual patients (r=0.607; P< 0.001).
Conclusion: Primary RCC ADC histogram analysis shows dynamic changes with sunitinib. Patients in whom the tumour ADC histogram demonstrated high baseline AUClow or a greater-than-median increase in AUClow with treatment had reduced OS.
Written by:
Bharwani N, Miquel ME, Powles T, Dilks P, Shawyer A, Sahdev A, Wilson PD, Chowdhury S, Berney DM, Rockall AG. Are you the author?
Department of Radiology, Barts Health NHS Trust, St Bartholomew's Hospital, King George V Building, West Smithfield, London EC1A 7BE, UK; Department of Clinical Physics, Barts Health NHS Trust, St Bartholomew's Hospital, 4th Floor Dominion House, 60 St Bartholomew's Close, London EC1A 7BE, UK; Barts and the London NIHR Cardiovascular Biomedical Research Unit, Centre for Advanced Cardiovascular Imaging, Queen Mary University of London, Bonner Road, London E2 9JX, UK; Barts Cancer Institute, Experimental Cancer Medicine Centre, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK; Department of Medical Oncology, St Bartholomew's Hospital, 7th Floor Gloucester House, London EC1A 7BE, UK; Department of Medical Oncology, Guys and St Thomas' NHS Foundation Trust, Great Maze Pond, London SE1 9RT, UK; Barts Cancer Institute, Molecular Oncology and Cellular Pathology, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
Reference: Br J Cancer. 2014 Feb 4;110(3):616-24.
doi: 10.1038/bjc.2013.790
PubMed Abstract
PMID: 24366299
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