title: Quantitative CT variables enabling response prediction in neoadjuvant therapy with EGFR-TKIs: are they different from those in neoadjuvant concurrent chemoradiotherapy?
abstract: OBJECTIVE
  To correlate changes of various CT parameters after the neoadjuvant treatment in patients with lung adenocarcinoma with pathologic responses, focused on their relationship with different therapeutic options, particularly of EGFR-TKI and concurrent chemoradiation therapy (CCRT) settings.
  
  
  METHODS
  We reviewed pre-operative CT images of primary tumors and surgical specimens obtained after neoadjuvant therapy (TKI, n = 23; CCRT, n = 28) from 51 patients with lung adenocarcinoma. Serial changes in tumor volume, density, mass, skewness/kurtosis, and size-zone variability/intensity variability) were assessed from CT datasets. The changes in CT parameters were correlated with histopathologic responses, and the relationship between CT variables and histopathologic responses was compared between TKI and CCRT groups.
  
  
  RESULTS
  Tumor volume, mass, kurtosis, and skewness were significant predictors of pathologic response in CCRT group in univariate analysis. Using multivariate analysis, kurtosis was found to be independent predictor. In TKI group, intensity variability and size-zone variability were significantly decreased in pathologic responder group. Intensity variability was found to be an independent predictor for pathologic response on multivariate analysis.
  
  
  CONCLUSIONS
  Quantitative CT variables including histogram or texture analysis have potential as a predictive tool for response evaluation, and it may better reflect treatment response than standard response criteria based on size changes.
authors.affiliation: Department of Radiology and Center for Imaging Science, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yousun
authors.initials: Y
authors.lastname: Chong
authors.affiliation: Department of Radiology and Center for Imaging Science, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae-Hun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Radiology and Center for Imaging Science, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Ahn
authors.affiliation: Department of Radiology and Center for Imaging Science, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.affiliation: Division of Hemato-Oncology, Department of Internal Medicine, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Myung-Ju
authors.initials: MJ
authors.lastname: Ahn
authors.affiliation: Department of Thoracic Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jhingook
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Thoracic Surgery, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Young Mog
authors.initials: YM
authors.lastname: Shim
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joungho
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yoon-La
authors.initials: YL
authors.lastname: Choi
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000532:radiotherapy; D000368:Aged; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D066246:ErbB Receptors / Q000037:antagonists & inhibitors*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D066246:ErbB Receptors