Diagnostic imaging in the preoperative management of lung cancer

Piezoresistivity modeling of soft tissue electrical-mechanical properties: A validation study

In general, the electrical property of soft tissues is sensitive to the force applied to their surface. To further study the relationship between the force and the electrical property of soft tissues, this paper attempts to investigate the effect of static and higher-order stresses on electrical properties. Overall, a practical experimental platform is designed to acquire the force information and the electrical property of soft tissues during a contact procedure, which is featured different compression stimuli, such as constant pressing force, constant pressing speed, and step-force compression, etc. Furthermore, the piezoresistive characteristic is innovatively introduced to model the mechanical-electrical properties of soft tissue. Finite Element Modeling (FEM) is adopted to fit the static piezoresistivity of the soft tissue. Finally, experimental studies were performed to demonstrate the effect of stress on the electrical properties and the feasibility of the proposed piezoresistive model to describe soft tissues' mechanical and electrical properties.

Application of clinical bioinformatics in lung cancer-specific biomarkers

The fact that lung cancer is a heterogeneous disease suggests that there is a high likelihood that effective lung cancer biomarkers will need to address patient-specific molecular defects, clinical characters, and aspects of the tumor microenvironment. In this transition, clinical bioinformatics tools and resources are the most appropriate means to improve the analysis, as major biological databases are now containing clinical data alongside genomics, proteomics, and other biological data. Clinical bioinformatics comprises a series of concepts and approaches that have been used successfully both to delineate novel biological mechanisms and to drive translational advances in individualized healthcare. In this article, we outline several of emerging clinical bioinformatics-based strategies as they apply specifically to lung cancer.

The Diagnostic Value of MR Imaging in Determining the Lymph Node Status of Patients with Non-Small Cell Lung Cancer: A Meta-Analysis

Purpose To summarize existing evidence of thoracic magnetic resonance (MR) imaging in determining the nodal status of non-small cell lung cancer (NSCLC) with the aim of elucidating its diagnostic value on a per-patient basis (eg, in treatment decision making) and a per-node basis (eg, in target volume delineation for radiation therapy), with results of cytologic and/or histologic examination as the reference standard. Materials and Methods A systematic literature search for original diagnostic studies was performed in PubMed, Web of Science, Embase, and MEDLINE. The methodologic quality of each study was evaluated by using the Quality Assessment of Diagnostic Accuracy Studies 2, or QUADAS-2, tool. Hierarchic summary receiver operating characteristic curves were generated to estimate the diagnostic performance of MR imaging. Subgroup analyses, expressed as relative diagnostic odds ratios (DORs) (rDORs), were performed to evaluate whether publication year, methodologic quality, and/or method of evaluation (qualitative [ie, lesion size and/or morphology] vs quantitative [eg, apparent diffusion coefficients in diffusion-weighted images]) affected diagnostic performance. Results Twelve of 2551 initially identified studies were included in this meta-analysis (1122 patients; 4302 lymph nodes). On a per-patient basis, the pooled estimates of MR imaging for sensitivity, specificity, and DOR were 0.87 (95% confidence interval [CI]: 0.78, 0.92), 0.88 (95% CI: 0.77, 0.94), and 48.1 (95% CI: 23.4, 98.9), respectively. On a per-node basis, the respective measures were 0.88 (95% CI: 0.78, 0.94), 0.95 (95% CI: 0.87, 0.98), and 129.5 (95% CI: 49.3, 340.0). Subgroup analyses suggested greater diagnostic performance of quantitative evaluation on both a per-patient and per-node basis (rDOR = 2.76 [95% CI: 0.83, 9.10], P = .09 and rDOR = 7.25 [95% CI: 1.75, 30.09], P = .01, respectively). Conclusion This meta-analysis demonstrated high diagnostic performance of MR imaging in staging hilar and mediastinal lymph nodes in NSCLC on both a per-patient and per-node basis. (©) RSNA, 2016 Online supplemental material is available for this article.

Outcomes of initial surgery in patients with clinical N2 non-small cell lung cancer who met 4 specific criteria

PURPOSE

The role of surgery for patients with non-small cell lung cancer (NSCLC) with clinical mediastinal lymph node metastasis (N2) remains controversial. We specified 4 criteria for performing initial surgery in these patients (single-station N2, non-bulky N2, N2 with regional mode of spread, and N2 without N1) and examined the outcomes to validate the treatment options.

METHODS

Between September 2002 and December 2010, of 1290 patients who underwent complete resection for NSCLC, 808 patients underwent initial standard resection, including 779 patients with cN0-1 and 29 with cN2. We compared the outcomes, and evaluated patients with cN2-pN2.

RESULTS

The median follow-up was 45.5 months (3-119 months). Seventy (9.0 %) and 24 (82.8 %) patients had p-N2 in the cN0-1 and cN2 groups, respectively (p < 0.0001). The 5-year disease-free survival (DFS) rates in the cN0-1 and cN2 groups were 73.3 and 50.6 %, respectively (p = 0.0053), and the 5-year overall survival (OS) rates were 81.3 and 71.1 %, respectively (p = 0.051). The 5-year DFS and OS of patients with cN2-pN2 were 52.5 and 72.6 %, respectively.

CONCLUSIONS

Patients with clinical N2 disease based on our criteria represent a highly specific group with a favorable prognosis. Resection should therefore be the initial treatment for these patients.

Management of unexpected intraoperative bleeding during thoracoscopic pulmonary resection: a single institutional experience

PURPOSE

Unexpected intraoperative bleeding during thoracoscopic surgery, necessitating emergency conversion to thoracotomy, is gradually being reported. We reviewed our experience of encountering unexpected bleeding during thoracoscopic surgery.

METHODS

We defined "unexpected intraoperative bleeding" as the need for hemostatic procedures with angiorrhaphy, with or without a sealant. The location, cause, and management of injured vessels, and perioperative outcomes were investigated and compared with those for patients without injured vessels.

RESULTS

Between 2007 and 2014, a total of 241 thoracoscopic anatomical pulmonary resections were performed at our hospital. Twenty (8.3 %) of these patients required hemostatic procedures with angiorrhaphy, with or without a sealant. The main injured vessels were the pulmonary artery (n = 13) and vein (n = 3) and the main causes of injury were related to technical issues with energy devices and staplers. There were no morbidities related to intraoperative bleeding. The operation time and blood loss were significantly greater in the patients with vessel injury than in those without vessel injury, but perioperative morbidities and the duration of chest tube insertion (4.5 vs. 3.5 days, average, p = 0.20) and postoperative hospital stay (12.7 vs. 11.0 days, average, p = 0.08) were not significantly different.

CONCLUSIONS

The frequency of unexpected bleeding was relatively high in this series, but its management and outcomes were satisfactory in terms of safety.

Correlation between histological invasiveness and the computed tomography value in pure ground-glass nodules

Purpose

The purpose of this study was to evaluate the correlation between histological invasiveness and the computed tomography (CT) value and size in pure ground-glass nodules (GGNs) to determine optimal “follow-up or resection” strategies.

Methods

Between 2001 and 2014, 78 resected, pure GGNs were retrospectively evaluated. The maximum diameter and CT value of pure GGNs were measured using a computer graphics support system.

Results

All GGNs with a maximum diameter ≤10 mm and CT value ≤−600 Hounsfield units (HU) were considered to be noninvasive lesions, while 21 of 26 (81 %) with a maximum diameter >10 mm and CT value >−600 HU were considered to be invasive lesions. With respect to the correlation between each histological type and pure GGN with a maximum diameter ≤10 mm and CT value ≤−600 HU, the specificity was 90 % and the sensitivity and negative predictive value were both 100 % in atypical adenomatous hyperplasia (AAH), while the specificity was 58 % and the sensitivity and positive predictive value were 0 % in minimally invasive and invasive adenocarcinoma.

Conclusion

Pure GGNs with a maximum diameter of ≤10 mm and CT value of ≤−600 HU are nearly always pre-invasive lesions; therefore, surgery should be carefully selected in such patients.

Is lower zone mediastinal nodal dissection always mandatory for lung cancer in the lower lobe?

PURPOSE

Dissection of the lower zone mediastinal nodes is mandatory during systematic nodal dissection for lung cancer. However, the significance of lower zone lymph node metastasis (LZM) in lung cancer remains unclear. Therefore, we aimed to identify the predictive factors for LZM in patients with lower lobe lung cancer.

METHODS

A retrospective study was conducted on 257 patients with lower lobe lung cancer, in whom pulmonary resection and mediastinal nodal dissection were performed between 2009 and 2013. The radiological factors on thin-section computed tomography scans (TSCT) and several conventional clinical factors were evaluated as possible predictors of LZM.

RESULTS

Twenty (7.8 %) patients exhibited LZM. The majority of the tumors were especially located in segment 10 (50 %). All patients showed a solid appearance on TSCT. In a univariate analysis, the tumor location, a solid appearance and the clinical T factor significantly predicted LZM (p = 0.011, 0.005, 0.018). Furthermore, based on a multivariate analysis, the tumor location in segment 10 significantly predicted LZM in patients with lower lobe solid lung cancer (p = 0.031).

CONCLUSION

The appropriate surgical strategy for lower zone lymph node dissection should be selected based on the tumor location and the findings of TSCT, due to the high frequency of LZM (19.6 %), especially in patients with pure solid lung cancer in segment 10.

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.