title: CT texture analysis: a potential tool for prediction of survival in patients with metastatic clear cell carcinoma treated with sunitinib.
abstract: BACKGROUND
  To assess CT texture based quantitative imaging biomarkers in the prediction of progression free survival (PFS) and overall survival (OS) in patients with clear cell renal cell carcinoma undergoing treatment with Sunitinib.
  
  
  METHODS
  In this retrospective study, measurable lesions of 40 patients were selected based on RECIST criteria on standard contrast enhanced CT before and 2 months after treatment with Sunitinib. CT Texture analysis was performed using TexRAD research software (TexRAD Ltd, Cambridge, UK). Using a Cox regression model, correlation of texture parameters with measured time to progression and overall survival were assessed. Evaluation of combined International Metastatic Renal-Cell Carcinoma Database Consortium Model (IMDC) score with texture parameters was also performed.
  
  
  RESULTS
  Size normalized standard deviation (nSD) alone at baseline and follow-up after treatment was a predictor of OS (Hazard ratio (HR) = 0.01 and 0.02; 95% confidence intervals (CI): 0.00 - 0.29 and 0.00 - 0.39; p = 0.01 and 0.01). Entropy following treatment and entropy change before and after treatment were both significant predictors of OS (HR = 2.68 and 87.77; 95% CI = 1.14 - 6.29 and 1.26 - 6115.69; p = 0.02 and p = 0.04). nSD was also a predictor of PFS at baseline and follow-up (HR = 0.01 and 0.01: 95% CI: 0.00 - 0.31 and 0.001 - 0.22; p = 0.01 and p = 0.003). When nSD at baseline or at follow-up was combined with IMDC, it improved the association with OS and PFS compared to IMDC alone.
  
  
  CONCLUSIONS
  Size normalized standard deviation from CT at baseline and follow-up scans is correlated with OS and PFS in clear cell renal cell carcinoma treated with Sunitinib.
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Center, University of Toronto, Rm AG-46, 2075 Bayview Ave, Toronto, Onatrio, M4N 3M5, Canada. masoom.haider@sunnybrook.ca.
authors.forename: Masoom A
authors.initials: MA
authors.lastname: Haider
authors.affiliation: Department of Radiology, North Bristol NHS Trust, Southmead Hospital, Bristol, UK.
authors.forename: Alireza
authors.initials: A
authors.lastname: Vosough
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Center, University of Toronto, Rm AG-46, 2075 Bayview Ave, Toronto, Onatrio, M4N 3M5, Canada.
authors.forename: Farzad
authors.initials: F
authors.lastname: Khalvati
authors.affiliation: Sunnybrook Health Sciences Center, Toronto, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kiss
authors.affiliation: Institute of Nuclear Medicine, University College London, London, UK.
authors.forename: Balaji
authors.initials: B
authors.lastname: Ganeshan
authors.affiliation: Sunnybrook Odette Cancer Centre, Division of medical Oncology, University of Toronto, Toronto, ON, Canada.
authors.forename: Georg A
authors.initials: GA
authors.lastname: Bjarnason
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D005260:Female; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011237:Predictive Value of Tests; D011758:Pyrroles / Q000627:therapeutic use*; D011856:Radiographic Image Enhancement / Q000379:methods*; D000077210:Sunitinib; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D011758:Pyrroles; D000077210:Sunitinib
keywords: CT image features; CT texture analysis; Metastatic clear cell carcinoma; Prediction of outcome; Quantitative imaging biomarkers