Dynamic contrast-enhanced MRI parameters as biomarkers for the effect of vatalanib in patients with non-small-cell lung cancer

Dynamic contrast-enhanced MRI perfusion parameters are imaging biomarkers for angiogenesis in lung cancer

BACKGROUND

Quantitative parameters of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) may have the potential to reflect angiogenesis and proliferation of pulmonary neoplasms.

PURPOSE

To verify whether DCE-MRI can identify pulmonary neoplasm property and evaluate the correlation of DCE-MRI perfusion parameters with microvessel density (MVD) and Ki-67 in lung cancer.

MATERIAL AND METHODS

This study enrolled 65 patients with one pulmonary neoplasm who underwent computed tomography-guided percutaneous lung biopsy with pathological diagnosis (43 malignant, 22 benign; mean age = 59.71 ± 11.72 years). All patients did DCE-MRI before biopsy. Quantitative MRI parameters including endothelial transfer constant (K^trans), flux rate constant (K_ep), and fractional extravascular extracellular space (EES) volume (V_e) were calculated by extended Tofts linear model. MVD was evaluated by CD34-expressing tumor vessels. Proliferation was assessed by Ki-67 staining. The correlations of parameters with MVD and Ki-67 expression were analyzed.

RESULTS

K^trans and K_ep values were significantly increased in malignant lesions compared to benign lesions (P = 0.001 and 0.022, respectively), whereas no statistical difference in V_e was found. The CD34 expression was positively correlated to K^trans (r = 0.608; P = 0.004) and K_ep (r = 0.556; P = 0.001). Subsequent subtype analyses also showed positive correlations of K^trans and K_ep with MVD in adenocarcinoma group (r = 0.550 and 0.563; P = 0.012 and 0.015, respectively). No significant correlation was found between these parameters and Ki-67.

CONCLUSION

K^trans and K_ep may distinguish benign and malignant pulmonary neoplasm. K^trans and K_ep, with their positive correlation to MVD, can be used as non-invasive parameters reflecting lung cancer angiogenesis.

Assessment of Early Response to Lung Cancer Chemotherapy by Semiquantitative Analysis of Dynamic Contrast-Enhanced MRI

Objective

To evaluate the early chemotherapy response in patients with lung cancer using semiquantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI).

Methods

Twenty-two patients with lung cancer treated with chemotherapy were subjected to DCE-MRI at two time points: before starting treatment and after one week of therapy. The image data were collected by DCE-MRI, and the semiquantitative parameters including positive enhancement integral (PEI), signal enhancement ratio (SER), maximum slope of increase (MSI), and time to peak (TTP) were calculated. After chemotherapy, the parameters and relevant variations between the responders and nonresponders were compared with Mann–Whitney U tests. Student's t-test for paired samples was used to evaluate the temporal changes between pre- and posttreatment images.

Results

The patients were categorized as 13 responders and 9 nonresponders based on the tumor response evaluation. After chemotherapy, the PEI, SER, and MSI were significantly increased in responders compared with the pretreatment values (P < 0.05), while no obvious decrease in TTP was observed (P > 0.05). However, 9 nonresponders showed no significant changes in PEI, SER, MSI, and TTP values, as compared with those of pretreatment (P > 0.05). Moreover, the increase of PEI was more dramatically in responders than in nonresponders (P < 0.05), but no significantly differences were observed in SER, MSI, and TTP (P > 0.05).

Conclusion

Semiquantitative analysis of DCE-MRI could provide a reliable noninvasive method for assessing early chemotherapy response in lung cancer patients.

Reproducibility of dynamic contrast enhanced MRI derived transfer coefficient Ktrans in lung cancer

Dynamic contrast enhanced MRI (DCE-MRI) is a useful method to monitor therapy assessment in malignancies but must be reliable and comparable for successful clinical use. The aim of this study was to evaluate the inter- and intrarater reproducibility of DCE-MRI in lung cancer. At this IRB approved single centre study 40 patients with lung cancer underwent up to 5 sequential DCE-MRI examinations. DCE-MRI were performed using a 3.0T system. The volume transfer constant Ktrans was assessed by three readers using the two-compartment Tofts model. Inter- and intrarater reliability and agreement was calculated by wCV, ICC and their 95% confident intervals. DCE-MRI allowed a quantitative measurement of Ktrans in 107 tumors where 91 were primary carcinomas or intrapulmonary metastases and 16 were extrapulmonary metastases. Ktrans showed moderate to good interrater reliability in overall measurements (ICC 0.716-0.841; wCV 30.3-38.4%). Ktrans in pulmonary lesions ≥ 3 cm showed a good to excellent reliability (ICC 0.773-0.907; wCV 23.0-29.4%) compared to pulmonary lesions < 3 cm showing a moderate to good reliability (ICC 0.710-0.889; wCV 31.6-48.7%). Ktrans in intrapulmonary lesions showed a good reliability (ICC 0.761-0.873; wCV 28.9-37.5%) compared to extrapulmonary lesions with a poor to moderate reliability (ICC 0.018-0.680; wCV 28.1-51.8%). The overall intrarater agreement was moderate to good (ICC 0.607-0.795; wCV 24.6-30.4%). With Ktrans, DCE MRI offers a reliable quantitative biomarker for early non-invasive therapy assessment in lung cancer patients, but with a coefficient of variation of up to 48.7% in smaller lung lesions.

Dual-input tracer kinetic modeling of dynamic contrast-enhanced MRI in thoracic malignancies

Pulmonary perfusion with dynamic contrast‐enhanced (DCE‐) MRI is typically assessed using a single‐input tracer kinetic model. Preliminary studies based on perfusion CT are indicating that dual‐input perfusion modeling of lung tumors may be clinically valuable as lung tumors have a dual blood supply from the pulmonary and aortic system. This study aimed to investigate the feasibility of fitting dual‐input tracer kinetic models to DCE‐MRI datasets of thoracic malignancies, including malignant pleural mesothelioma (MPM) and nonsmall cell lung cancer (NSCLC), by comparing them to single‐input (pulmonary or systemic arterial input) tracer kinetic models for the voxel‐level analysis within the tumor with respect to goodness‐of‐fit statistics. Fifteen patients (five MPM, ten NSCLC) underwent DCE‐MRI prior to radiotherapy. DCE‐MRI data were analyzed using five different single‐ or dual‐input tracer kinetic models: Tofts‐Kety (TK), extended TK (ETK), two compartment exchange (2CX), adiabatic approximation to the tissue homogeneity (AATH) and distributed parameter (DP) models. The pulmonary blood flow (BF), blood volume (BV), mean transit time (MTT), permeability‐surface area product (PS), fractional interstitial volume (v_I), and volume transfer constant (K^Trans) were calculated for both single‐ and dual‐input models. The pulmonary arterial flow fraction (γ), pulmonary arterial blood flow (BF_PA) and systemic arterial blood flow (BF_A) were additionally calculated for only dual‐input models. The competing models were ranked and their Akaike weights were calculated for each voxel according to corrected Akaike information criterion (cAIC). The optimal model was chosen based on the lowest cAIC value. In both types of tumors, all five dual‐input models yielded lower cAIC values than their corresponding single‐input models. The 2CX model was the best‐fitted model and most optimal in describing tracer kinetic behavior to assess microvascular properties in both MPM and NSCLC. The dual‐input 2CX‐model‐derived BF_A was the most significant parameter in differentiating adenocarcinoma from squamous cell carcinoma histology for NSCLC patients.

Contrast-enhanced magnetic resonance imaging with a novel nano-size contrast agent for the clinical diagnosis of patients with lung cancer

Recent studies have indicated that magnetic resonance imaging (MRI) efficiently diagnoses lung cancer. However, the efficacy of MRI in diagnosing lung cancer requires improving for patients in the early stage of the disease. In the present study, a novel nano-sized contrast agent of chistosan/Fe₃O₄-enclosed bispecific antibodies (BsAbCENS) was introduced, which targeted carcino-embryonic antigen (CEA) and neuron-specific enolase (NSE) in lung cancer cells. The diagnostic efficacy of contrast-enhanced MRI with BsAbCENS (CEMRI-BsAbCENS) was investigated in a total of 182 patients with suspected lung cancer who had high serum levels of CEA and NSE. BsAbCENS was administered by pulmonary inhalation prior to the MRI scan. The results revealed that CEA and NSE were overexpressed in human lung cancer cell lines. BsAbCENS bound with CEA and NSE on the surface of human lung cancer cells and produced a higher signal intensity than MRI alone for the diagnosis of patients with lung cancer. The diagnostic data revealed that CEMRI-BsAbCENS diagnosed 124/182 lung cancer cases, whereas CEMRI only diagnosed 98/182, which was significantly less (P<0.01). In addition, the survival rate of patients with lung cancer diagnosed by CEMRI-BsAbCENS was significantly higher than the mean 5-year survival rate (P<0.01). Furthermore, the pharmacodynamics demonstrated that BsAbCENS was metabolized within 24 h. The results of the present study indicate that the efficacy and accuracy of lung cancer diagnosis are improved by CEMRI-BsAbCENS. In conclusion, these results provide a potential novel protocol for the diagnosis of tumors in patients with suspected early stage lung cancer.

Expression of PIM-1 in salivary gland adenoid cystic carcinoma: Association with tumor progression and patients' prognosis

Pim-1 proto-oncogene, serine/threonine kinase (PIM-1) phosphorylates a series of substrates to exert its oncogenic function in numerous malignancies. The present study investigated the clinical significance of the PIM-1 protein, apoptosis status and apoptosis-associated proteins, including forkhead box O3a (FOXO3a), B cell lymphoma-2 (BCL-2) and BCL-2-associted agonist of cell death (BAD), were investigated in salivary gland adenoid cystic carcinoma (ACC) tissues. PIM-1 expression levels in 4 pairs of ACC tissues and corresponding normal salivary gland tissues were determined by western blot analysis. PIM-1, FOXO3a, BAD and BCL-2 expression levels in 60 ACC tissues were evaluated by immunohistochemistry (IHC). A terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling assay was performed to detect the apoptosis status of ACC tissues. PIM-1 was revealed to be highly expressed in ACC tissues compared with adjacent normal tissues. IHC staining results demonstrated high expression ratios of PIM-1, FOXO3a, BCL-2 and BAD [33.33% (20/60), 51.67% (31/60), 51.67% (31/60) and 55% (33/60)], respectively, and significant correlations between the expression of PIM-1 and FOXO3a and BCL-2 (P<0.05). Apoptotic rates were significantly associated with PIM-1, FOXO3a, BCL-2 and BAD expression levels (P<0.05). PIM-1 expression levels were significantly associated with tumor size, lymph node involvement, nerve invasion, distant metastasis and weakly associated with tumor node metastasis stage. Kaplan-Meier survival curves revealed that PIM-1 expression level was significantly associated with disease-free survival of patients with ACC (P=0.009). Cox regression multivariate analysis results revealed that histotype, distant metastasis and apoptotic rate were independent prognosis factors for ACC. Assessment of PIM-1 may be useful in investigating the malignant behaviors of ACC and predicting the outcome of patients with ACC.

[Quantitative Imaging Assessment of Tumor Response to Chemoradiation in Lung Cancer]

精准医疗的实施要求及时准确地对治疗疗效进行评估，以便于治疗方案的调整和优化，从而进一步提高疗效，改善预后。以定量评估为基础的影像组学以其无创、直观和可重复的特点在临床疗效评估方面具有不可替代的作用。本文将综述定量影像学在肺癌放化疗疗效评估中的应用现状及其相关进展。

Incorporation of Antiangiogenic Therapy Into the Non-Small-Cell Lung Cancer Paradigm

Although molecular targeted agents have improved the treatment of lung cancer, their use has largely been restricted to limited subsets of the overall population that carry specific mutations. Angiogenesis, the formation of new blood vessels from existing networks, is an attractive, more general process for the development of targeted anticancer therapies, because it is critical for the growth of solid tumors, including non-small-cell lung cancer. Growing tissues require a vascular supply within a few millimeters. Therefore, solid tumors create a proangiogenic microenvironment to facilitate the development of new tumor-associated blood vessels, thus providing an adequate vascular supply for continued tumor growth. Antiangiogenic agents can specifically target the vascular endothelial growth factor (VEGF) signaling pathways, broadly inhibit multiple tyrosine kinases, or interfere with other angiogenic processes, such as disruption of existing tumor vasculature. The present report provides an overview of antiangiogenic therapy for non-small-cell lung cancer, including both currently approved antiangiogenic therapies (bevacizumab [anti-VEGF] and ramucirumab [anti-VEGF receptor 2] monoclonal antibodies), and a variety of promising novel agents in development. Although recent data have demonstrated promising efficacy for some novel agents, the overall development of antiangiogenic therapy has been hampered by redundancy in signaling pathways and the highly heterogeneous nature of tumors. An improved understanding of the molecular basis of angiogenesis will guide the development of new antiangiogenic therapies and the identification of biomarkers to predict which patients with lung cancer are most likely to benefit from antiangiogenic therapy.

Mechanism and non-mechanism based imaging biomarkers for assessing biological response to treatment in non-small cell lung cancer

Therapeutic options in locally advanced non-small cell lung cancer (NSCLC) have expanded in the past decade to include a palate of targeted interventions such as high dose targeted thermal ablations, radiotherapy and growing platform of antibody and small molecule therapies and immunotherapies. Although these therapies have varied mechanisms of action, they often induce changes in tumour architecture and microenvironment such that response is not always accompanied by early reduction in tumour mass, and evaluation by criteria other than size is needed to report more effectively on response. Functional imaging techniques, which probe the tumour and its microenvironment through novel positron emission tomography and magnetic resonance imaging techniques, offer more detailed insights into and quantitation of tumour response than is available on anatomical imaging alone. Use of these biomarkers, or other rational combinations as readouts of pathological response in NSCLC have potential to provide more accurate predictors of treatment outcomes. In this article, the robustness of the more commonly available positron emission tomography and magnetic resonance imaging biomarker indices is examined and the evidence for their application in NSCLC is reviewed.