title: Assessing response to treatment in non--small-cell lung cancer: role of tumor volume evaluated by computed tomography.
abstract: BACKGROUND
  We set out to investigate whether volumetric tumor measurements allow for a prediction of treatment response, as measured by patient survival, in patients with advanced non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  Patients with nonresectable NSCLC (stage III or IV, n = 100) who were repeatedly evaluated for treatment response by computed tomography (CT) were included in a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. Tumor response was measured by comparing tumor volumes over time. Patient survival was compared with Response Evaluation Criteria in Solid Tumors (RECIST) using Kaplan-Meier survival statistics and Cox regression analysis.
  
  
  RESULTS
  The median overall patient survival was 553 days (standard error, 146 days); for patients with stage III NSCLC, it was 822 days, and for patients with stage IV disease, 479 days. The survival differences were not statistically significant (P = .09). According to RECIST, 5 patients demonstrated complete response, 39 partial response, 44 stable disease, and 12 progressive disease. Patient survival was not significantly associated with RECIST class, the change of the sum of tumor diameters (P = .98), nor the change of the sum of volumetric tumor dimensions (P = .17).
  
  
  CONCLUSIONS
  In a group of 100 patients with advanced-stage NSCLC, neither volumetric CT measurements of changes in tumor size nor RECIST class significantly predicted patient survival. This observation suggests that size response may not be a sufficiently precise surrogate marker of success to steer treatment decisions in individual patients.
authors.affiliation: Department of Radiology, University of California, Davis, Sacramento, CA. Electronic address: friedrich.knollmann@ucdmc.ucdavis.edu.
authors.forename: Friedrich D
authors.initials: FD
authors.lastname: Knollmann
authors.affiliation: Department of Radiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Rohan
authors.initials: R
authors.lastname: Kumthekar
authors.affiliation: Department of Radiology, University of Pittsburgh, Pittsburgh, PA.
authors.forename: David
authors.initials: D
authors.lastname: Fetzer
authors.affiliation: University of Pittsburgh, Hillman Cancer Center, Pittsburgh, PA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Socinski
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D005500:Follow-Up Studies; D020408:Health Insurance Portability and Accountability Act; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden; D014481:United States
keywords: CT; Carcinoma; Imaging; Outcome; Survival