title: Doubling times and CT screen–detected lung cancers in the Pittsburgh Lung Screening Study.
abstract: BACKGROUND
  As computed tomography (CT) screening for lung cancer becomes more widespread, volumetric analyses, including doubling times, of CT-screen detected lung nodules and lung cancers may provide useful information in the follow-up and management of CT-detected lung nodules and cancers.
  
  
  OBJECTIVE
  To analyze doubling times in CT screen detected lung cancers and compare prevalent and nonprevalent cancers and different cell types on non small cell lung cancer.
  
  
  METHODS
  We performed volumetric and doubling time analysis on 63 non–small cell lung cancers detected as part of the Pittsburgh Lung Screening Study using a commercially available VITREA 2 workstation and VITREA VITAL nodule segmentation software.
  
  
  RESULTS
  Doubling times (DT) were divided into three groups: rapid (DT<183 d), typical (DT 183–365 d), and slow (DT>365 d). Adenocarcinoma/bronchioloalveolar carcinoma comprised 86.7% of the slow DT group compared with 20% of the rapid DT group. Conversely, squamous cell cancer comprised 60% of the rapid DT group compared with 3.3% of the slow DT group. Twenty-eight of 42 (67%) prevalent and 2 of 21 (10%) nonprevalent cancers were in the slow DT group (P<0.0001; Fisher's exact test). Twenty-four of 32 (75%) prevalent and 1 of 11 (9%) nonprevalent adenocarcinomas were in the slow DT group (P<0.0002; Fisher's exact test).
  
  
  CONCLUSIONS
  Volumetric analysis of CT-detected lung cancers is particularly useful in AC/BAC. Prevalent cancers have a significantly slower DT than nonprevalent cancers and a higher percentage of adenocarcinoma/bronchioloalveolar carcinoma. These results should affect the management of indeterminant lung nodules detected on screening CT scans.
authors: Department of Medicine, Heart, Lung and Esophageal Surgery Institute, University of Pittsuburgh, Pittsburgh, PA 15232, USA. wilsondo@upmc.edu
authors: David O
authors: DO
authors: Wilson
authors: Adam
authors: A
authors: Ryan
authors: Carl
authors: C
authors: Fuhrman
authors: Matthew
authors: M
authors: Schuchert
authors: Steven
authors: S
authors: Shapiro
authors: Jill M
authors: JM
authors: Siegfried
authors: Joel
authors: J
authors: Weissfeld
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging*; D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000000981:diagnostic imaging*; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging*; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D010414:Pennsylvania; D012720:Severity of Illness Index; D013997:Time Factors; D036542:Tomography, Spiral Computed / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*