title: Computed tomography attenuation predicts the growth of pure ground-glass nodules.
abstract: OBJECTIVE
  Cases of lung cancer with pure ground-glass nodules (GGNs) have been detected with increasing frequency since the advent of computed tomography (CT), and growth is sometimes noted during follow-up. The objective of this study was to evaluate the potential predictive factors for pure GGN growth.
  
  
  METHODS
  We retrospectively examined 124 cases involving pure GGNs. Patients were monitored for > 2 years using high-resolution CT. After a median follow-up period of 57.0 months, GGNs showed growth in 64 of the 124 cases. We compared the patient characteristics and tumor properties of cases with and without growth. The predictive value of the mean CT attenuation for GGN growth was evaluated using receiver operating characteristic curve analysis.
  
  
  RESULTS
  Univariate analysis revealed significant differences between mean CT attenuation values in patients with and without growth (-602.9 ± 90.7 Hounsfield units [HU] vs -705.7 ± 77.7HU, P < 0.0001). The final incidence of growth was estimated to be significantly higher for lesions with a mean CT attenuation value of ≥ -670HU (n = 62; 93.2%) than for lesions with values of < -670HU (n = 62; 31.6%; P < 0.0001). The sensitivity and specificity for predicting tumor growth using this cutoff value were 78.1% and 80.0%, respectively (area under the curve, 0.81).
  
  
  CONCLUSIONS
  The mean CT attenuation value could be useful in predicting the growth of GGNs.
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan. Electronic address: tks1976@shinshu-u.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Eguchi
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kondo
authors.affiliation: Department of Radiology, Shinshu University, Matsumoto, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kawakami
authors.affiliation: Department of Radiology, Shinshu University, Matsumoto, Japan.
authors.forename: Mina
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Department of Pathology, Shinshu University, Matsumoto, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yoshizawa
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hara
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Shunichiro
authors.initials: S
authors.lastname: Matsuoka
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Takeda
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Miura
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Agatsuma
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Sakaizawa
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tominaga
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Saito
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Toishi
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Hamanaka
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hashizume
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shiina
authors.affiliation: Division of Cardiovascular Surgery, Department of Surgery, Shinshu University, Asahi 3-1-1, 390-8621 Matsumoto, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Amano
authors.affiliation: Comprehensive Cancer Center, Shinshu University, Matsumoto, Japan.
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Koizumi
authors.affiliation: Division of Thoracic Surgery, Department of Surgery, Shinshu University, Matsumoto, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D000368:Aged; D019540:Area Under Curve; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
keywords: Adenocarcinoma; Computed tomography; Ground glass nodule; Lung cancer; Region of interest; Tumor growth