title: Role of CT and PET Imaging in Predicting Tumor Recurrence and Survival in Patients with Lung Adenocarcinoma: A Comparison with the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society Classification of Lung Adenocarcinoma.
abstract: BACKGROUND
  Recently, a new lung adenocarcinoma classification scheme was published. The prognostic value of this new classification has not been elaborated together with the value of imaging biomarkers including computed tomography (CT) and positron emission tomography (PET).
  
  
  METHODS
  We reviewed pathologic specimens and imaging characteristics of primary tumors from 723 consecutive patients who underwent surgical resection for lung adenocarcinoma. On pathology, the predominant histologic subtype and pattern group were quantified. Tumor-shadow disappearance ratio (TDR) on CT and maximum standardized uptake value (SUVmax) on PET were assessed. The relationships between those variables and survival (overall survival [OS] and disease-free survival) were analyzed by using Kaplan-Meier curves and Cox regression analyses.
  
  
  RESULTS
  The median follow-up period was 3.8 years. There were 137 patients (19%) with recurrence and 167 patients (23%) with metastasis after surgical resection. Among 723 patients, 35 patients (4.8%) had adenocarcinoma in situ, 34 patients (4.7%) had minimally invasive adenocarcinoma, 125 patients (17.3%) had lepidic predominant, 314 patients (43.4%) had acinar predominant, 65 patients (9.0%) had papillary predominant, 23 patients (3.2%) had micropapillary predominant, 113 patients (15.6%) had solid predominant, and 14 patients (1.9%) had variant adenocarcinomas. OS and disease-free survival rates were significantly different according to TDR on CT and SUVmax on PET, predominant subtypes, and pattern groups. On multivariate analysis, the SUVmax (p < 0.001), TDR (p = 0.038), and pattern group (p = 0.015) were independent predictors of OS.
  
  
  CONCLUSIONS
  TDR on CT, SUVmax on PET, and the new histologic classification schemes appear to be promising parameters for the prognostic stratification of patients with lung adenocarcinomas, allowing for the triage of patients who necessitate further staging workup and adjuvant therapy.
authors.affiliation: *Department of Radiology and Center for Imaging Science, †Department of Pathology, ‡Department of Nuclear Medicine, §Division of Respiratory and Critical Medicine of the Department of Internal Medicine, ‖Department of Thoracic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; and ¶Department of Pathology, Kyungpook National University Hospital, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.forename: So Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Ji Yun
authors.initials: JY
authors.lastname: Jeong
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.forename: O Jung
authors.initials: OJ
authors.lastname: Kwon
authors.forename: So Hee
authors.initials: SH
authors.lastname: Song
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Kim
authors.forename: Jhingook
authors.initials: J
authors.lastname: Kim
authors.forename: Young Mog
authors.initials: YM
authors.lastname: Shim
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*