Lepidic Predominant Pulmonary Lesions (LPL): CT-based Distinction From More Invasive Adenocarcinomas Using 3D Volumetric Density and First-order CT Texture Analysis.

RATIONALE AND OBJECTIVES: This study aimed to differentiate pathologically defined lepidic predominant lesions (LPL) from more invasive adenocarcinomas (INV) using three-dimensional (3D) volumetric density and first-order texture histogram analysis of surgically excised stage 1 lung adenocarcinomas. MATERIALS AND METHODS: This retrospective study was institutional review board approved and Health Insurance Portability and Accountability Act compliant. Sixty-four cases of pathologically proven stage 1 lung adenocarcinoma surgically resected between September 2006 and October 2015, including LPL (n = 43) and INV (n = 21), were evaluated using high-resolution computed tomography. Quantitative measurements included nodule volume, percent solid volume (% solid), and first-order texture histogram analysis including skewness, kurtosis, entropy, and mean nodule attenuation within each histogram quartile. Binomial logistic regression models were used to identify the best set of parameters distinguishing LPL from INV. RESULTS: Univariate analysis of 3D volumetric density and histogram features was statistically significant between LPL and INV groups (P < .05). Accuracy of a binomial logistic model to discriminate LPL from INV based on size and % solid was 85.9%. With optimized probability cutoff, the model achieves 81% sensitivity, 76.7% specificity, and area under the receiver operating characteristic curve of 0.897 (95% confidence interval, 0.821-0.973). An additional model based on size and mean nodule attenuation of the third quartile (Hu_Q3) of the histogram achieved similar accuracy of 81.3% and area under the receiver operating characteristic curve of 0.877 (95% confidence interval, 0.790-0.964). CONCLUSIONS: Both 3D volumetric density and first-order texture analysis of stage 1 lung adenocarcinoma allow differentiation of LPL from more invasive adenocarcinoma with overall accuracy of 85.9%-81.3%, based on multivariate analyses of either size and % solid or size and Hu_Q3, respectively.

Initial experience with endobronchial ultrasound in an academic thoracic surgery program.

BACKGROUND: Mediastinoscopy is considered the gold standard for evaluating mediastinal lymph nodes. However, endobronchial ultrasound-guided transbronchial needle aspiration has lately offered a less invasive alternative, with the ability to obtain nodal samples under direct visualization. Recent literature found an early learning curve for this technique. We present the initial experience of 4 thoracic surgeons with the procedure. MATERIALS AND METHODS: A retrospective chart review was performed on the first 51 patients on whom an endobronchial ultrasound-guided transbronchial needle aspiration was performed from January 5, 2007, to July 24, 2008. This group included 43 patients with a history or known diagnosis of malignancy as well as 8 patients with a presumed sarcoidosis diagnosis. All negative results were confirmed with mediastinoscopy. The technique's sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were assessed. RESULTS: A total of 73 lymph nodes underwent biopsy in 51 patients. These individuals included 34 men and 17 women, with an average age of 62 years (range, 21-89 years). No surgical or postoperative complications were noted. Overall, a correct diagnosis was established in 88% of the patients (45 of 51). After the first 25 cases (a mean of 6 cases per surgeon), a technique modification was adapted to increase diagnostic yield. The first 25 cases had a 72.22% sensitivity and 80% accuracy, whereas the last 26 cases had a 95.45% sensitivity and 96.15% accuracy (P = .07). CONCLUSION: Endobronchial ultrasound-guided transbronchial needle aspiration is a quickly mastered technique that offers a safe, minimally invasive, and accurate means to evaluate mediastinal lymph nodes.

Sentinel lymph node mapping and molecular staging in nonsmall cell lung carcinoma.

BACKGROUND: Lymph node (LN) involvement predicts recurrence in patients who have undergone resection of apparently localized nonsmall cell lung carcinoma (NSCLC). Standard detection methods for LN disease have a low sensitivity, and many patients with apparent N0 disease status develop recurrent disease. Molecular techniques can improve the detection of micrometastases, whereas sentinel lymph node (SLN) mapping can indicate which LN may contain micrometastases. These methods, although potentially complementary, have not, to the authors' knowledge, been used together previously. METHODS: The authors used SLN mapping and molecular staging to improve the detection of LN micrometastases in patients with NSCLC. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for cytokeratin-7 (CK7), expressed both in normal lung and in malignant lung, was used to identify tumor-derived material in LN. RESULTS: SLN mapping was performed in 13 patients, with 1-3 SLNs identified in each patient, and sufficient RNA for RT-PCR was obtained in 12 of these 13 patients. Eleven of 12 tumors expressed CK7. Overall, 32 LNs were positive for CK7, including 13 of 21 SLNs. Ten of 11 patients with evaluable SLNs had at least 1 CK7-positive SLN. Routine pathology showed Stage I disease in eight patients, T3N0 disease in one patient, and LN-positive disease in two patients. Of the nine patients with N0 disease according to routine pathology that was evaluable by RT-PCR, eight patients were upstaged by this technique. All patients with positive LN status by routine pathology who were evaluable by RT-PCR analysis had positive RT-PCR results. CONCLUSIONS: LN micrometastases were common in resected NSCLC, including patients with N0 disease according to routine pathology. SLN mapping was useful for identifying disease-containing LNs. This approach may be useful for stratifying histologically N0 patients into higher risk and lower risk groups.