Contrast-enhanced MRI for the staging of bronchogenic carcinoma: comparison with CT and histopathologic staging--preliminary results

Magnetic resonance imaging for N staging in non-small cell lung cancer: A systematic review and meta-analysis

Background

Lymph node staging in non-small cell lung cancer (NSCLC) is essential for deciding appropriate treatment. This study systematically reviews the literature regarding the diagnostic performance of magnetic resonance imaging (MRI) in lymph node staging of patients with NSCLC, and determines its pooled sensitivity and specificity.

Methods

PubMed and Embase databases and the Cochrane library were used to search for relevant studies. Two reviewers independently identified the methodological quality of each study. A meta-analysis of the reported sensitivity and specificity of each study was performed.

Results

Nine studies were included. These studies had moderate to good methodological quality. Pooled sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR−) and diagnosis odds ratio (DOR) for per-patient based analyses (7 studies) were 74%, 90%, 7.5, 0.26, and 36.7, respectively, and those for per-lymph node based analyses (5 studies) were 77%, 98%, 42.24, 0.21, and 212.35, respectively. For meta-analyses of quantitative short time inversion recovery imaging (STIR) and diffusion-weighted imaging (DWI), pooled sensitivity and specificity were 84% and 91%, and 69% and 93%, respectively. Pooled LR+ and pooled LR− were 8.44 and 0.18, and 8.36 and 0.36, respectively. The DOR was 56.29 and 27.2 respectively.

Conclusion

MRI showed high specificity in the lymph node staging of NSCLC. Quantitative STIR has greater DOR than quantitative DWI. Large, direct, and prospective studies are needed to compare the diagnostic power of STIR versus DWI; consistent diagnostic criteria should be established.

Guidelines for multimodality radiological staging of lung cancer

Lung cancer is among the most common type of cancers and is a leading cause of cancer-related deaths with smoking representing the leading risk factor. It is classified into non-small cell lung cancer (NSCLC) representing 70-80% of cases and small cell lung cancer (SCLC) which has neuroendocrine properties with poor outcome. Staging of NSCLC is based on the TNM classification system while SCLC was usually classified into limited and extensive disease, though the use of TNM staging system for SCLC is recommended. Imaging studies are used to determine the pre-operative staging of lung cancer. Accurate radiological staging is essential to determine tumor resectability as well as to avoid futile surgeries and to assess patient's outcome. Moreover, radiological examinations are used for the evaluation of tumor response to treatment. This manuscript will review the utilization of imaging studies in the management of lung cancer based on the most recent guidelines by the National Comprehensive Cancer Network (NCCN).

Using diffusion-weighted MR imaging for tumor detection in the collapsed lung: a preliminary study

The usefulness of diffusion-weighted magnetic resonance (MR) imaging (DWI) for differentiating central lung cancer from postobstructive lobar collapse (POC) was investigated. Thirty-three cases suspected of lung cancer and POC on chest bolus computed tomography (CT) underwent thoracic MR imaging examinations. MR examinations were performed using a 1.5-T clinical scanner. Scanning sequences were T1-weighted imaging, T2-weighted imaging (T2WI) and DWI with b=0, 500 s/mm(2), four excitations and segmented breath-holding. The densities and signals of cancer and postobstructive collapsed lung were compared on bolus-enhanced CT, T2W and DW images. Statistical analyses were performed with chi-square test, paired t-test, non-parameter test and kappa statistics. Differentiation between cancer and POC was possible on bolus CT, T2W and DW images in 14, 21 and 26 patients, respectively. Eight cases that were impossible to differentiate on T2W images were distinguishable on DWI, demonstrating that DWI is complementary to T2WI. Using a combination of T2W and DW images, 88% (29/33) of cases were differentiated on MR imaging. Thus, a combination of T2W and DW imaging is superior to bolus-CT or T2WI alone. The contrast-to-noise ratio of DWI was significantly higher than that of T2WI. Agreement between two independent observers on the differential ability of lung cancer and POC was higher for DWI (kappa=0.474) than for T2WI (kappa=0.339). The degree of consolidation around the cancer was negatively correlated with the degree of artifact and degree of deformation. It is feasible to use DWI to differentiate lung cancer from POC. DWI played a role in confirming and providing complementary information to that obtained from T2WI. Our data indicate that using a combination of the two scanned sequences was the best means of distinguishing between lung cancer and POC.

Staging of non-small cell lung cancer: imaging of intrathoracic disease

This article reviews the contribution of diagnostic imaging to the intrathoracic staging of non-small cell lung cancer. The principle features of the current staging system are discussed along with the relative roles of the various imaging modalities in the evaluation of the primary tumour and metastatic disease. The emerging role of positron emission tomography with fluorodeoxyglucose (FDG-PET) as a clinically useful, potentially cost effective, complementary imaging technique is also reviewed.

MR imaging of lung cancer

Since publication of the Radiologic Diagnostic Oncology Group Report in 1991, the clinical application of pulmonary magnetic resonance (MR) imaging to patients with lung cancer has been limited. Computed tomography has been much more widely available for staging of lung cancer in clinical situations. Currently, ventilation and perfusion scintigraphy is the only modality that demonstrates pulmonary function while 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography is the only modality that reveals biological glucose metabolism of lung cancer. However, recent advancements in MR imaging have made it possible to evaluate morphological and functional information in lung cancer patients more accurately and quantitatively. Pulmonary MR imaging may hold significant potential to substitute for nuclear medicine examinations. In this review, we describe recent advances in MR imaging of lung cancer, focusing on (1) characterization of solitary pulmonary nodules; (2) differentiation from secondary change; evaluation of (3) medastinal invasion, (4) chest wall invasion, (5) lymph node metastasis, and (6) distant metastasis; and (7) pulmonary functional imaging. We believe that further basic studies, as well as clinical applications of newer MR techniques, will play an important role in the management of patients with lung cancer.

Dynamic contrast-enhanced breath-hold MR imaging of thoracic malignancy using cardiac compensation

The purpose of this paper was to evaluate the use of dynamic gadopentetate dimeglumine-enhanced, breath-hold spoiled gradient-recalled (SPGR) MR imaging with cardiac compensation (CMON) compared to spin-echo MR imaging in patients with thoracic malignancy. We retrospectively reviewed MR images from 29 patients with thoracic tumors. MR imaging included axial electrocardiogram (ECG)-gated T1-weighted, fast spin echo (FSE) T2-weighted, and contrast-enhanced breath-hold fast multiplanar SPGR imaging with CMON, which selects the phase-encoding gradient based on the phase within the cardiac cycle. Images were reviewed for lung masses, mediastinal or hilar tumor, disease of the pleura, chest wall, and bones and vascular compression or occlusion. Contrast-enhanced fast multiplanar SPGR imaging with CMON produces images of the chest that are free of respiratory artifact and have diminished vascular pulsation artifact. ECG-gated T1-weighted images were preferred for depicting mediastinal and hilar tumor. The gadopentetate dimeglumine-enhanced fast multiplanar SPGR images were useful for depicting chest wall tumor, vascular compression or thrombosis, osseous metastases, and in distinguishing a central tumor mass from peripheral lung consolidation. Pleural tumor was depicted best on the FSE T2-weighted images and the contrast-enhanced SPGR images. As an adjunct to spin echo T1-weighted and T2-weighted imaging, contrast-enhanced fast multiplanar SPGR imaging with CMON is useful in the evaluation of thoracic malignancy.

Clinical impact of adrenal expansive lesions in bronchial carcinoma

PURPOSE

To estimate the prevalence of adrenal expansive lesions in patients with bronchial carcinoma, and assess the relationships among adrenal masses, TNM classification, and histology of the bronchial carcinoma, and to reveal other signs of inoperability in these patients.

MATERIAL AND METHODS

CT findings of the thorax and upper abdomen in 96 patients with bronchial carcinoma were reviewed. Brain- and upper abdominal metastases, together with TNM classification and histology of the bronchial carcinoma, was recorded. CT was performed with 10-mm slice thickness from the thorax aperture to the renal hilum under i.v. contrast medium injection.

RESULTS

Eight adrenal expansive lesions (1.5-10 cm, mean 4.6 cm) were revealed in 6 of the 96 patients (6.3%). Two of these patients, classified as N0, had metastases in other organs; one had brain metastases and the other liver metastases. The bronchial carcinomas in the remaining 4 patients were classified as N3. Three of the patients had adenocarcinoma, one each of small-cell-, large-cell-, and unclassified bronchial carcinoma. Squamous cell carcinoma was most common in the total patient population, but no patient with adrenal masses showed this histologic type.

CONCLUSION

The finding of adrenal expansive lesions in bronchial carcinoma has little clinical impact, because these patients usually show other signs of inoperability. Hence, the value of upper abdominal CT as a routine examination is questionable.

Inhalation MR lymphography: a new method for selective enhancement of the lung hilar and mediastinal lymph nodes

On MR lymphography, a new approach to the lung hilar and mediastinal nodes was developed in an animal model. Five rabbits were made to inhale iron colloid (cideferron) that was nebulized to aerosol. Two days after inhalation of the agent, the mediastinal lymph nodes decreased in signal on SE 2000/30 and SE 2000/60 images and proved to have iron on histological evaluation, whereas the popliteal nodes did not have any iron. Experimental results indicate that inhalational administration can deliver the agent to the pulmonary lymphatic system and has the potential of lung hilar and mediastinal MR lymphography.

Radioimmunoimaging of non-small cell lung cancer with 111In- and 99mTc-labeled monoclonal anti-CEA-antibodies

Radiolabeled monoclonal anti-CEA antibodies were used for radioimmunolocalization (RIL) of non-small cell lung cancer; in 30 patients with 111In labeled anti CEA F(ab')2 fragment (BW 431/31) and in 16 with 99mTc-labeled intact MoAb (BW 431/26). RIL results were compared with those of other imaging modalities. Paraffin sections from some patients were also studied immunohistochemically using anti-CEA antibody. Patients with 111In labeled MoAB were imaged twice 1-4 days after injection and for image enhancement pulmonary and liver/spleen subtraction were performed. Twenty-seven of 28 primary tumors were positive and metastases were detected in all patients. The total number of lesions was 78 of which 61 (78%) could be detected by RIL. For verification CT was applied to the study of 46 lesions detected by RIL. We found 6 unknown lesions subsequently verified histologically. Using subtraction techniques we detected 9 lesions in 4 patients, later verified as pulmonary metastases, not detected in unprocessed images. Pleural, mediastinal and pericardial lesions were also better delineated in subtracted images than in unprocessed images. Imaging of non-small cell lung cancer with 99mTc-labeled MoAB was performed twice 4-24 h after injection. RIL results were compared with other imaging methods; CT US, conventional radiography, and immunohistochemistry. Twelve out of 16 patients with suspected or known lung cancer had positive immunoscintigrams; 19 of 25 lesions could be detected by RIL. There were 5 false positive and 2 true negative findings. Immunoperoxidase (IP) stainings of paraffin sections of the tumours from 7 patients were performed using two different anti-CEA antibodies; BW 431/26 and ZCEA1. None of the seven tumors examined by immunohistochemistry were negative when stained by BW 431/26, which was the antibody used for immunoscintigraphy.