Diffusion-Weighted Magnetic Resonance Imaging for Early Detection of Chemotherapy Resistance in Non-Small Cell Lung Cancer

Abstract

BackgroundThe aim of this study was to examine the role of magnetic resonance imaging-diffusion weighted imaging (MRI-DWI) in the early detection of chemotherapy resistance in non-small cell lung cancer (NSCLC) patients.Material/MethodsMRI-DWI and computed tomography (CT) were carried out in 75 patients with newly diagnostic NSCLC before and after first, second, fourth, and sixth cycles of chemotherapy. Resistance to chemotherapy was assessed based on the change in the largest tumor diameter after chemotherapy. Diffusion of water molecule in each lesion was quantitatively measured by apparent diffusion coefficient (ADC). The diagnostic results of DWI after first and second cycle of chemotherapy were analyzed by the area under receiver operating characteristics curve (ROC).ResultsAmong the patients, 43 patients were chemo-resistance while 32 patients were chemo-sensitive. The ADC changing rate between second and first cycle of chemotherapy was significantly higher in chemo-sensitive patients compared with chemo-resistance patients (t=3.236, P=0.002). The ROC showed cutoff values of the ADC changing rate after first and second cycles of chemotherapy for resistance/sensitive discrimination were 23.6% and 5.56%, respectively. DWI after first and second cycles of therapy showed sensitivities of 55.8% and 55.8%, specificities of 65.6% and 87.5%, and area under ROC of 0.568 and 0.733, respectively.ConclusionsADC changing rate between first and second cycles of chemotherapy could sensitively distinguish chemo-sensitive and chemo-resistant tumors at earlier stages, which may direct treatment adjustment and improve the prognosis of patients.

Volumetric Analysis of Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Predicting the Response to Chemotherapy in Patients With Locally Advanced Non–Small Cell Lung Cancer

“…This may be due to the cytotoxic effect of chemotherapeutic drugs destroying the integrity of tumor cells, increasing intracellular necrosis, inducing tumor cell apoptosis, or directly killing tumor cells, resulting in decreased cell density and increased water molecule diffusion movement after effective chemotherapy. The results for ADC were the same with previous studies 3–7 in patients with primary and recurrent lung tumors. Theoretically, the D value is more representative of the water molecular diffusion than ADC because of the separation of water molecule diffusion and microcirculation perfusion.…”

“…The contradictory results may be due to the diverse research objectives, the heterogeneous scanning and postprocessing techniques, and the different evaluation criteria. However, the ADC was found to have an ineffective predictive value even before treatment, similar to the results of some studies 3,7,39 . The possible causes were the hybrid effect of the ADC value and the small sample size.…”

“…However, the ADC was found to have an ineffective predictive value even before treatment, similar to the results of some studies. 3,7,39 The possible causes were the hybrid effect of the ADC value and the small sample size. Therefore, in the future, we need to expand the sample size for further discussion.…”

“…3,4 Diffusion-weighted imaging (DWI) is a radiation-and contrastfree functional imaging technique for quantitative evaluating the movement of water molecules within tissues. Studies [3][4][5][6][7][8] have shown that apparent diffusion coefficient (ADC) changes before the decrease of tumor size and thus can potentially monitor the curative effect of chemotherapy in lung cancer patients and predict prognoses at early stages. However, the ADC is based on a monoexponential model of DWI and is influenced by perfusion effects.…”