title: Dynamic contrast-enhanced MRI in patients with muscle-invasive transitional cell carcinoma of the bladder can distinguish between residual tumour and post-chemotherapy effect.
abstract: BACKGROUND
  Treatment of muscle-invasive bladder cancer with chemotherapy results in haemorrhagic inflammation, mimicking residual tumour on conventional MR images and making interpretation difficult. The aim of this study was to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to estimate descriptive and tracer kinetic parameters post-neoadjuvant chemotherapy and to investigate whether parameters differed in areas of residual tumour and chemotherapy-induced haemorrhagic inflammation (treatment effect, Tr-Eff).
  
  
  METHODS
  Twenty-one patients underwent DCE-MRI scans with 2.5s temporal resolution before and following neoadjuvant chemotherapy. Regions-of-interest (ROIs) were defined in areas suspicious of residual tumour on T2-weighted MRI scans. Data were analysed semi-quantitatively and with a two-compartment exchange model to obtain parameters including relative signal intensity (rSI80s) and plasma perfusion (Fp) respectively. The bladder was subsequently examined histologically after cystectomy for evidence of residual tumour and/or Tr-Eff. Differences in parameters measured in areas of residual tumour and Tr-Eff were examined using Student's t-test.
  
  
  RESULTS
  Twenty-four abnormal sites were defined after neoadjuvant chemotherapy. On pathology, 10 and 14 areas were identified as residual tumour and Tr-Eff respectively. Median rSI80s and Fp were significantly higher in areas of residual tumour than Tr-Eff (rSI80s = 2.9 vs 1.7, p < 0.001; Fp = 20.7 vs 9.1 ml/100ml/min, p = 0.03). The sensitivity and specificity for differentiating residual tumour from Tr-Eff were 70% and 100% (rSI80s), 60% and 86% (Fp), and 75% and 100% when combined.
  
  
  CONCLUSIONS
  DCE-MRI parameters obtained post-treatment are capable of distinguishing between residual tumour and treatment effect in patients treated for bladder cancer with neoadjuvant chemotherapy.
authors.affiliation: School of Cancer and Enabling Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Wilmslow Road, Manchester M20 4BX, UK. Electronic address: Stephanie.donaldson1@nhs.net.
authors.forename: Stephanie B
authors.initials: SB
authors.lastname: Donaldson
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Bonington
authors.forename: Lucy E
authors.initials: LE
authors.lastname: Kershaw
authors.forename: Richard
authors.initials: R
authors.lastname: Cowan
authors.forename: Jeanette
authors.initials: J
authors.lastname: Lyons
authors.forename: Tony
authors.initials: T
authors.lastname: Elliott
authors.forename: Bernadette M
authors.initials: BM
authors.lastname: Carrington
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy* / Q000473:pathology*; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019042:Muscle Neoplasms / Q000473:pathology* / Q000517:prevention & control; D009220:Myositis / Q000139:chemically induced* / Q000473:pathology*; D009361:Neoplasm Invasiveness; D018365:Neoplasm, Residual; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000473:pathology
chemical_list: D003287:Contrast Media
keywords: Bladder cancer; Magnetic resonance imaging; Neoadjuvant chemotherapy; Perfusion; Tracer kinetic model; Treatment effects