title: Radiological prediction of tumor invasiveness of lung adenocarcinoma on thin-section CT.
abstract: To evaluate thin-section computed tomography (CT) (TSCT) features that differentiate adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IVA), and to determine the size of solid portion on CT that correlates to pathological invasive components. Forty-eight patients were included. Nodules were classified into ground-glass nodule (GGN), part-solid, solid, and heterogeneous. Visual density of GGNs was subjectively evaluated using reference standard images: faint GGN (Ga), <-700 Hounsfield unit (HU); intermediate GGN (Gb), from -700 to -400 HU; dense GGN (Gc), >-400 HU; and mixed (Ga + Gb, Ga + Gc, and Gb + Gc). The evaluated TSCT findings included margin of nodule, distribution of solid portion, distribution of air bronchiologram, and pleural indentation. The longest diameters of the solid portion and the entire tumor were measured. Invasive diameters were measured in pathological specimens. Twenty-two AISs (16 GGNs [7 Ga, 5 Gb, 2 Gc, 1 Ga + Gc, 1 Gb + Gc], 4 part-solids, and 2 heterogeneous), 6 MIAs (1 GGN [Gb + Gc], 3 part-solids, and 2 solids), and 20 IVAs (1 GGN [Gb], 3 part-solids, and 16 solid) were found. The longest diameter (mean ± standard deviation) of the solid portion and total tumor were 9.7 ± 9.7 and 18.9 ± 5.6 mm, respectively. Significant differences in TSCT findings between AIS and IVA were margin of nodule (Pearson chi-squared test, P = 0.004), distribution of air bronchiologram (P = 0.0148), and pleural indentation (P = 0.0067). A solid portion >5.3 mm on TSCT indicated MIA or IVA, and >7.3 mm indicated IVA (receiver operating characteristic analysis, P < 0.0001). Irregular margin, air bronchiologram with disruption and/or irregular dilatation, and pleural indentation may distinguish IVA from AIS. A 5.3 to 7.3 mm solid portion on TSCT indicates MIA/IVA, and a solid portion >7.3 mm on TSCT indicates IVA.
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, Itami, Hyogo Department of Diagnostic Pathology, University of Tsukuba, Tsukuba, Ibaraki Department of Pathology Department of Respiratory Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yanagawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Morii
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shintani
authors.forename: Meinoshin
authors.initials: M
authors.lastname: Okumura
authors.forename: Akinori
authors.initials: A
authors.lastname: Hata
authors.forename: Maki
authors.initials: M
authors.lastname: Fujiwara
authors.forename: Osamu
authors.initials: O
authors.lastname: Honda
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tomiyama
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D000077192:Adenocarcinoma of Lung; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*