title: CT texture analysis in colorectal liver metastases: A better way than size and volume measurements to assess response to chemotherapy?
abstract: BACKGROUND
  Response Evaluation Criteria In Solid Tumors (RECIST) are known to have limitations in assessing the response of colorectal liver metastases (CRLMs) to chemotherapy.
  
  
  OBJECTIVE
  The objective of this article is to compare CT texture analysis to RECIST-based size measurements and tumor volumetry for response assessment of CRLMs to chemotherapy.
  
  
  METHODS
  Twenty-one patients with CRLMs underwent CT pre- and post-chemotherapy. Texture parameters mean intensity (M), entropy (E) and uniformity (U) were assessed for the largest metastatic lesion using different filter values (0.0 = no/0.5 = fine/1.5 = medium/2.5 = coarse filtration). Total volume (cm(3)) of all metastatic lesions and the largest size of one to two lesions (according to RECIST 1.1) were determined. Potential predictive parameters to differentiate good responders (n = 9; histological TRG 1-2) from poor responders (n = 12; TRG 3-5) were identified by univariable logistic regression analysis and subsequently tested in multivariable logistic regression analysis. Diagnostic odds ratios were recorded.
  
  
  RESULTS
  The best predictive texture parameters were Δuniformity and Δentropy (without filtration). Odds ratios for Δuniformity and Δentropy in the multivariable analyses were 0.95 and 1.34, respectively. Pre- and post-treatment texture parameters, as well as the various size and volume measures, were not significant predictors. Odds ratios for Δsize and Δvolume in the univariable logistic regression were 1.08 and 1.05, respectively.
  
  
  CONCLUSIONS
  Relative differences in CT texture occurring after treatment hold promise to assess the pathologic response to chemotherapy in patients with CRLMs and may be better predictors of response than changes in lesion size or volume.
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Sheng-Xiang
authors.initials: SX
authors.lastname: Rao
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Doenja Mj
authors.initials: DM
authors.lastname: Lambregts
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Roald S
authors.initials: RS
authors.lastname: Schnerr
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Rianne Cj
authors.initials: RC
authors.lastname: Beckers
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Monique
authors.initials: M
authors.lastname: Maas
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Radiology, S. Anna Hospital, University of Ferrara, Ferrara, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Albarello
authors.affiliation: Department of Pathology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Riedl
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Cornelis Hc
authors.initials: CH
authors.lastname: Dejong
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Milou H
authors.initials: MH
authors.lastname: Martens
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands; Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Luc A
authors.initials: LA
authors.lastname: Heijnen
authors.affiliation: Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Walter H
authors.initials: WH
authors.lastname: Backes
authors.affiliation: Department of Surgery, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Geerard L
authors.initials: GL
authors.lastname: Beets
authors.affiliation: Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Meng-Su
authors.initials: MS
authors.lastname: Zeng
authors.affiliation: Department of Radiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands; Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Regina Gh
authors.initials: RG
authors.lastname: Beets-Tan
keywords: CT texture; Colorectal cancer; chemotherapy; liver metastases; response assessment