Radiology. 2016 May;279(2):590-6. doi: 10.1148/radiol.2015151120. Epub 2015 Dec 10.
Hsu JS1, Han IT1, Tsai TH1, Lin SF1, Jaw TS1, Liu GC1, Chou SH1, Chong IW1, Chen CY1.
Purpose
To evaluate the association of pleural tags with visceral pleural invasion of non-small cell lung cancer (NSCLC) that does not abut the pleural surface.
Materials and Methods
This retrospective study was approved by the institutional review board. Informed consent was waived. The study of NSCLC that does not abut the pleura in 141 patients (44 patients [31.2%] with visceral pleural invasion proved by pathologic analysis and 97 patients [68.8%] without pleural invasion) was conducted at a single tertiary center. The pleural tags were classified into three types (type 1, one or more linear pleural tag; type 2, one or more linear pleural tag with soft tissue component at the pleural end; and type 3, one or more soft tissue cord-like pleural tag) and prioritized into types 3, 2, and 1 when more than one type was present. Diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (LR) were calculated.
Results
In the absence of pleural tags, no pleural invasion was found. The presence of type 2 pleural tags was moderately associated with visceral pleural invasion with the following results: positive LR, 5.06; accuracy, 71%; sensitivity, 36.4%; specificity, 92.8%; PPV, 76.2%; and NPV, 69.6%. Type 1 pleural tags provided weak evidence to rule out visceral pleural invasion (positive LR, 0.38). Type 3 pleural tags indicated minimal increase in the likelihood of visceral pleural invasion (positive LR, 1.68).
Conclusion Type 2 pleural tags on conventional CT images can increase the accuracy of early diagnosis of visceral pleural invasion by NSCLC that does not abut the pleura. (©) RSNA, 2015.