title: The Attenuation Distribution Across the Long Axis (ADLA): Preliminary Findings for Assessing Response to Cancer Treatment.
abstract: Novel image analysis methods may be useful adjuncts to standard cancer treatment response assessment techniques. The attenuation distribution across the long axis (ADLA) is a simple measure of lesion heterogeneity that can be obtained while measuring the long axis diameter of a target lesion. The purpose of this study was to obtain preliminary validation of the ADLA method for predicting treatment response in a small clinical trial.
  
  
  
  Under an Institutional Review Board waiver, we obtained de-identified imaging and clinical data from a phase 2 trial of an investigational anticancer therapy at our institution. We retrospectively analyzed all patients with at least one liver metastasis measuring ≥15 mm on baseline contrast-enhanced computed tomography. For each patient at every imaging time point, up to two target liver lesions were evaluated using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and ADLA measurements. The ADLA was obtained as the standard deviation of the post-contrast computed tomography attenuation values in the portal venous phase across a linear function spanning the long-axis diameter. Using Kaplan-Meier survival analysis, the log-rank test was used to evaluate the ability of RECIST 1.1 and ADLA measurements to discriminate patients with longer overall survival (OS).
  
  
  
  Fifteen patients met inclusion criteria. Median survival was 149 days (range 57-487). Best overall response by the ADLA method successfully separated patients with longer OS (p = .04). Best overall response by RECIST 1.1 did not discriminate patients with longer survival (P > .05).
  
  
  
  In retrospective data analysis from a phase 2 clinical trial, the ADLA method was more predictive of OS than RECIST 1.1. Further studies are needed to explore the utility of this measurement in predicting response to cancer treatment.
authors.affiliation: Department of Radiology and Radiological Sciences, 1161 21st Ave. Nashville, TN 37232, Vanderbilt University, Nashville, TN 37235-3779, USA.
authors.forename: Nikita
authors.initials: N
authors.lastname: Lakomkin
authors.affiliation: Department of Biostatistics, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Hakmook
authors.initials: H
authors.lastname: Kang
authors.affiliation: College of Arts and Science, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Bennett
authors.initials: B
authors.lastname: Landman
authors.affiliation: College of Arts and Science, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: M Shane
authors.initials: MS
authors.lastname: Hutson
authors.affiliation: Department of Radiology and Radiological Sciences, 1161 21st Ave. Nashville, TN 37232, Vanderbilt University, Nashville, TN 37235-3779, USA; Institute of Imaging Science, Vanderbilt University, Nashville, Tennessee, USA. Electronic address: richard.abramson@vanderbilt.edu.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Abramson
mesh_terms: D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology; D003287:Contrast Media; D006801:Humans; D007091:Image Processing, Computer-Assisted; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000556:secondary; D011169:Portal Vein / Q000000981:diagnostic imaging; D066066:Response Evaluation Criteria in Solid Tumors; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media
keywords: Imaging biomarker; bevacizumab; cancer imaging; overall survival; quantitative imaging; response assessment