Predictive accuracy of lepidic growth subtypes in early-stage adenocarcinoma of the lung by quantitative CT histogram and FDG-PET

Daisuke Eriguchi; Yoshihisa Shimada; Kentaro Imai; Hideyuki Furumoto; Tetsuya Okano; Ryuhei Masuno; Jun Matsubayashi; Naohiro Kajiwara; Tatsuo Ohira; Norihiko Ikeda

doi:10.1016/j.lungcan.2018.08.027

Predictive accuracy of lepidic growth subtypes in early-stage adenocarcinoma of the lung by quantitative CT histogram and FDG-PET

Lung Cancer. 2018 Nov:125:14-21. doi: 10.1016/j.lungcan.2018.08.027. Epub 2018 Sep 3.

Affiliations

¹ Department of Surgery, Tokyo Medical University, Tokyo, Japan.
² Department of Surgery, Tokyo Medical University, Tokyo, Japan. Electronic address: zenkyu@za3.so-net.ne.jp.
³ Department of Radiology, Tokyo Medical University, Tokyo, Japan.
⁴ Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.

PMID: 30429012
DOI: 10.1016/j.lungcan.2018.08.027

Abstract

Objectives: The aim of this study was to analyze the accuracy of computed tomography (CT) and F-18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) to distinguish lepidic growth adenocarcinoma (LGA), including adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic-predominant adenocarcinoma, all of which have favorable survival outcomes, from the more aggressive and invasive non-LGA subtypes.

Materials and methods: We identified 225 patients with c-0/I adenocarcinoma of the lung who underwent PET/CT and 3DCT followed by complete resection. Maximum standardized uptake values (SUVmax) of FDG and several histogram parameters were analyzed. Histological grades were classified according to the predominant subtype (G1: lepidic; G3: micropapillary or solid; and G2: subtypes other than G1/G3).

Results: The proportion of pathological invasive factors (lymphatic vessel involvement/blood vessel invasion/pleural invasion/lymph node metastasis) of patients with preinvasive adenocarcinoma, G1, G2, and G3 tumors were 0%, 3.6%, 48.0%, and 100%, respectively; p < 0.001). Multivariate analysis with CT-related parameters demonstrated that 75^th percentile CT attenuation value (75^th%, p < 0.001) and maximum CT attenuation value (maxCT, p = 0.009) were associated with incidence of non-LGA, whereas the value of SUVmax demonstrated a significant correlation (p < 0.001). When all patients were dichotomized according to ground-glass opacities (GGO)/solid-dominancy for CT maximum diameter, a significant correlation with non-LGA was shown in patients with solid-dominant tumor on SUVmax (p < 0.001) and with GGO-dominant tumor on 75^th% (p = 0.006) and maxCT (p = 0.007). The combination of one of the two significant histogram parameters and SUVmax revealed higher predictive performance for pathological high malignant features (positive pathological invasive factors, non-LGA, and the highly malignant subtype covering G2 with moderately or poorly-differentiated carcinoma and G3) than the individual use of either factor.

Conclusion: The 75^th%, maxCT, and SUVmax were highly useful in distinguishing LGA from non-LGA in c-0/I adenocarcinoma.

Keywords: Adenocarcinoma; Histogram; PET/CT; Stage I; Three-dimensional CT.

MeSH terms

Adenocarcinoma of Lung / pathology*
Adult
Aged
Aged, 80 and over
Female
Fluorodeoxyglucose F18 / administration & dosage
Humans
Lung Neoplasms / pathology*
Lymph Nodes / pathology
Lymphatic Metastasis / pathology
Lymphatic Vessels / pathology
Male
Middle Aged
Positron Emission Tomography Computed Tomography / methods
Radiopharmaceuticals / administration & dosage
Retrospective Studies
Young Adult

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18