Apparent diffusion coefficient values detected by diffusion-weighted imaging in the prognosis of patients with locally advanced esophageal squamous cell carcinoma receiving chemoradiation

Predicting the effects of radiotherapy based on diffusion kurtosis imaging in a xenograft mouse model of esophageal carcinoma

The aim of the present study was to assess the predictive value of diffusion kurtosis imaging (DKI) on the effects of radiotherapy in a xenograft model of esophageal cancer. A total of 40 tumor-bearing mice, established by injection of Eca-109 cells in nude mice, were used. The experimental group (n=24) received a single dose of 15 Gy (6 MV by X-ray), and the control group (n=16) did not receive any treatment. Tumor volume, apparent diffusion coefficient (ADC), mean kurtosis (MK) and mean diffusivity (MD) of the two groups were compared, and the expression of aquaporin (AQP) 3 and necrosis ratio at matched time points in xenografts were also observed. There was a significant difference between the two groups from the 7th day of radiotherapy onwards; the xenograft volume of the experimental group was significantly smaller compared with the control group (P<0.05). On the 3rd day, the ADC and MD of the experimental group was significantly higher compared with the control group, and MK was significantly lower compared with the control group (P<0.05). On the 3rd day, AQP3 expression in the experimental group was lower compared with the control group, and the proportion of necrotic cells was higher compared with the control group (P<0.05). Single large fraction dose radiotherapy inhibited the growth of a xenografted esophageal tumor. Changes in ADC, MK and MD were observed prior to morphological changes in the tumor. The change in AQP3 expression and necrosis ratio was in also agreement with the DKI parameters assessed. DKI may thus provide early predictive ability on the effect of radiotherapy in esophageal carcinoma.

Clinical response assessment on DW-MRI compared with FDG-PET/CT after neoadjuvant chemoradiotherapy in patients with oesophageal cancer

PURPOSE

In about 30% of patients treated with neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection for locally advanced oesophageal cancer no vital tumour is found in the resection specimen. Accurate clinical response assessment is critical if deferral from surgery is considered in complete responders. Our study aimed to compare the performance of MRI and of FDG-PET/CT for the detection of residual disease after nCRT.

METHODS

Patients with oesophageal cancer eligible for nCRT and oesophagectomy were prospectively included. All patients underwent FDG-PET/CT and MRI before and between 6 and 8 weeks after nCRT. Two radiologists scored the MRI scans, and two nuclear medicine physicians scored the FDG-PET/CT scans using a 5-point score for residual disease. Histopathology after oesophagectomy represented the reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated for detection of residual tumour (ypT+), residual nodal disease (ypN+), and any residual disease (ypT+Nx/ypT0N+).

RESULTS

Seven out of 33 (21%) patients had a pathological complete response. The AUCs for individual readers to detect ypT+ were 0.71/0.70 on diffusion-weighted (DW)-MRI and 0.54/0.57 on FDG-PET/CT, and to detect ypN+ were 0.89/0.81 on DW-MRI and 0.75/0.71 on FDG-PET/CT. The AUCs/sensitivities/specificities for the individual readers to detect any residual disease were 0.74/92%/57% and 0.70/96%/43% on MRI; these were 0.49/69%/29% and 0.60/69%/43% on FDG-PET/CT, respectively.

CONCLUSION

MRI reached higher diagnostic accuracies than FDG-PET/CT for the detection of residual tumour in oesophageal cancer patients at 6 to 8 weeks after nCRT.

Histogram analysis of DCE-MRI for chemoradiotherapy response evaluation in locally advanced esophageal squamous cell carcinoma

AIMS

The aim of the study was to predict and assess treatment response by histogram analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to patients with locally advanced esophageal squamous cell carcinoma receiving chemoradiotherapy (CRT).

MATERIALS AND METHODS

Seventy-two patients with locally advanced esophageal squamous cell carcinoma who underwent DCE-MRI before and after chemoradiotherapy were enrolled and divided into the complete response (CR) group and the non-CR group based on RECIST. The histogram parameters (10th percentile, 90th percentile, median, mean, standard deviation, skewness, and kurtosis) of pre-CRT and post-CRT were compared using a paired Student's t test in the CR and non-CR groups, respectively. The histogram parameter differences between the CR and the non-CR groups were compared using an unpaired Student's t test. A receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance.

RESULTS

The histogram parameters of K^trans values were observed to have significantly decreased after chemoradiotherapy in the CR group. The CR responders showed significantly higher median, mean, and 10th and 90th percentile of pre-K^trans values than those of the non-CR group. The histogram analysis indicated the decreased heterogeneity in the CR group after CRT. Esophageal cancer with higher pre-K^trans and lower post-K^trans values indicated a good treatment response to CRT. Pre-K^trans-10th showed the best diagnostic performance in predicting the chemoradiotherapy response.

CONCLUSIONS

The histogram parameters of K^trans are useful in the assessment and prediction of the chemoradiotherapy response in patients with advanced esophageal squamous cell carcinoma. DCE-MRI could serve as an adjunctive imaging technique for treatment planning.

Prognostic value of 18F-FDG PET/MR imaging biomarkers in oesophageal squamous cell carcinoma

PURPOSE

To correlate the clinical stage and prognosis of oesophageal squamous cell carcinoma (SCC) using the imaging biomarkers from integrated positron emission tomography (PET)/magnetic resonance imaging (MRI).

METHODS

In total, 54 consecutive patients with oesophageal SCC who receive PET/MRI scan were recruited before treatment. The imaging biomarkers used were the mean and minimal apparent diffusion coefficients (ADC_mean and ADC_min), standardized uptake value (SUV), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) of tumours. The correlation between each imaging biomarker and survival was investigated using the Cox proportional hazards model.

RESULTS

ADC_mean was negatively correlated with SUV_max (r = -0.414, P =  0.025). ADC_min was negatively correlated with SUV_max (r = -0.423, P =  0.001) and SUV_peak (r = -0.402, P =  0.003), and was significantly lower in M1 than in M0 tumours (829.6 vs. 1069.8, P = 0.005). MTV was significantly higher in T3 + (P <  0.001), N1 + (P = 0.014) and TNM stage III + (P <  0.001) tumours. TLG was significantly higher in T3 + (P <  0.001), N1 + (P <  0.001), M1 (P =  0.045) and TNM stage III + (P <  0.001) tumours. The MTV/ADC_min ratio exhibited the highest area under the receiver operating characteristic curve (AUROC) for predicting M1 and advanced TNM stage tumours. Multivariate analysis for progression-free survival (PFS) and overall survival (OS) showed that a larger MTV/ADC_min was associated with a shorter PFS and OS (P = 0.024 and 0.046, respectively).

CONCLUSION

The imaging biomarkers in integrated PET/MRI may predict clinical stage and survival in patients with oesophageal SCC.

Contribution of magnetic resonance imaging to the management of esophageal diseases: A systematic review

PURPOSE

Currently available imaging modalities used to investigate the esophagus are irradiating or limited to the analysis of the esophageal lumen. Magnetic resonance imaging (MRI) is a non-invasive and non-radiating imaging technique that provides high degrees of soft tissue contrast. Newly developed fast MRI sequences allow for both morphological and functional assessment of the esophageal body and esophagogastric junction. The purpose of this systematic review was to identify the contribution of MRI to the diagnosis and management of esophageal diseases, such as gastroesophageal reflux, esophageal motility disorders, esophageal neoplasms, and portal hypertension.

METHODS

We performed a systematic search of the Medline (via Ovid), EMBASE (via Ovid), PubMed and Cochrane Library databases from inception to December 2018 inclusively, using the MESH major terms "magnetic resonance imaging" AND "esophagus".

RESULTS

The initial search retrieved 310 references, of which 56 were found to be relevant for the study. References were analysed and classified in different subheadings: MRI protocols for the esophagus, gastroesophageal reflux disease, achalasia and other esophageal motility disorders, esophageal cancer, portal hypertension and other esophageal conditions.

CONCLUSION

MR Esophagography might become a non-invasive, non-irradiating technique of choice following diagnostic esophagogastroduodenoscopy for the assessment of esophageal diseases.

Diffusion-weighted MRI with ADC mapping for response prediction and assessment of oesophageal cancer: A systematic review

PURPOSE

The aim was to perform a systematic review on the value of diffusion-weighted MRI (DW-MRI) with apparent diffusion coefficient (ADC) mapping in the prediction and assessment of response to chemo- and/or radiotherapy in oesophageal cancer.

MATERIALS AND METHODS

A systematic search was performed on Pubmed, Embase, Medline and Cochrane databases. Studies that evaluated the ADC for response evaluation before, during or after chemo- and/or radiotherapy were included. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess the quality of the included studies.

RESULTS

Fourteen studies, comprising 516 patients, in which the response to treatment in oesophageal cancer was evaluated on ADC maps were included. Acquisition parameter settings for DW-MRI and ROI placement varied substantially. The reference standard was RECIST or endoscopic assessment in eight non-surgery studies and histopathology after surgery in six studies. A high pre-treatment ADC significantly correlated with good response in three out of 12 studies; conversely, one study reported a significantly higher pre-treatment ADC in poor responders. In five out of eight studies good responders showed a significantly larger relative increase in ADC two weeks after the onset of treatment (range 23-59%) than poor responders (range 1.5-17%). After chemo- and/or radiotherapy ADC results varied considerably, amongst others due to large variation in the interval between completion of therapy and DW-MRI.

CONCLUSION

DW-MRI for response evaluation to chemo- and/or radiotherapy in oesophageal cancer shows variable methods and results. A large relative ADC increase after two weeks of treatment seems most predictive for good response.

Quantitative Multiparametric MRI May Augment the Response to Radiotherapy in Mid-Treatment Assessment of Patients with Esophageal Carcinoma

OBJECTIVE

The purpose of this study was to assess the mid-treatment response to radiotherapy (RT) using dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted imaging (DWI) in patients with esophageal cancer (EC).

METHODS

42 patients with squamous EC were prepared for DCE-MRI and DWI scans both before treatment (NRT) and after the fifth radiotherapy (5th RT). The patients were classified into two groups (complete response [CR] and partial response [PR]) according to tumor regression after treatment. The quantitative parameters of DCE-MRI (Ktrans, Kep, Ve, and ADC) were measured. A receiver operating characteristic curve (ROC) was used to detect the efficiency of the above parameters.

RESULTS

After 1 month of RT, 29 patients were classified as CR and 11 patients were classified as PR. In the NRT group, the p values of Ktrans, Kep, Ve, and ADC were 0.004, 0.078, 0.0008, and <0.0001, respectively. After the 5th RT, the p values of the above parameters were <0.001, 0.005, 0.108, and 0.365, respectively. In the NRT group, the areas under the ROC curves of Ktrans, Ve, and ADC were 0.790, 0.617, and 0.737; the sensitivity values were 89.3, 92.5, and 90.0%; the specificity values were 69.4, 27.5, and 50.0%. In the 5th RT group, the areas under the ROC curves of Ktrans and Kep were 0.816 and 0.804; the sensitivity values were 71.2 and 95.0%; the specificity values were 81.6 and 50.0%.

CONCLUSION

DCE-MRI combined with DWI is effective in the early prediction of radiotherapeutic response of EC after the 5th RT other than after the traditional final treatment.

Esophageal carcinoma: Intravoxel incoherent motion diffusion-weighted MRI parameters and histopathological correlations

BACKGROUND

The pathological grade of esophageal carcinoma is highly determinant of patient prognosis, but it still cannot be adequately evaluated preoperatively. Compared with conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM) diffusion-weighted MRI can separate true molecular diffusion and perfusion in tissues and has been shown to be useful in characterizing malignant tumors. There is no report that compared IVIM and conventional DWI in grading esophageal carcinoma.

PURPOSE

To prospectively determine the diagnostic performance of conventional DWI and IVIM models in differentiating the pathological differentiated grade of esophageal carcinoma.

STUDY TYPE

Prospective.

POPULATION

A cohort comprising 81 patients with newly diagnosed esophageal squamous cell carcinoma (ESCC) between December 2015 and August 2017 were evaluated.

FIELD STRENGTH/SEQUENCE

3.0T, axial echo-planer imaging, fast spin echo (FSE) sequence, IVIM sequence (b = 0, 20, 50, 80, 100, 150, 200, 400, 600, 800, 1000, 1200).

ASSESSMENT

Apparent diffusion coefficient (ADC), true ADC (ADC_slow ), pseudo ADC (ADC_fast ), and perfusion fraction (f) of each tumor were calculated by two independent radiologists. Histopathologic grade was used as the reference standard.

STATISTICAL TESTS

Games-Howell test; diagnostic accuracy; Spearman correlation; intraclass correlation coefficient; and Bland-Altman analysis. Receiver operating characteristics (ROC) curves.

RESULTS

ADC_slow demonstrated the highest area under curve (AUC) with a value of 0.830 (95% confidence interval [CI]: 0.730-0.904) and 0.816 (95% CI: 0.714-0.893) by two radiologists, followed by ADC with a value of 0.754 (95% CI: 0.646-0.843) and 0.761 (95% CI: 0.653-0.848). Good correlation was obtained between the histologic grade and ADC_slow (r_(R1)  = 0.748, r_(R2)  = 0.720) and ADC (r_(R1)  = 0.576, r_(R2)  = 0.571).

DATA CONCLUSION

ADC_slow and ADC had a significantly higher performance than the ADC_fast and f, and ADC_slow had a significantly higher performance than the ADC.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:253-261.

Dynamic contrast-enhanced MRI for advanced esophageal cancer response assessment after concurrent chemoradiotherapy

PURPOSE

We aimed to evaluate the treatment response of patients with esophageal cancer after concurrent chemoradiation therapy (CRT) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

METHODS

This retrospective study included 59 patients with histologically confirmed esophageal squamous cell carcinoma. The patients underwent DCE-MRI before and 4 weeks after CRT. Patients with complete response were defined as the CR group; partial response, stable disease, and progressive disease patients were defined as the non-CR group. DCE-MRI parameters (Ktrans, Ve, and Kep) were measured and compared between pre- and post-CRT in the CR and non-CR groups, respectively. Pre-CRT and post-CRT parameters were used to calculate the absolute change and the ratio of change. DCE-MRI parameters were compared between the CR and non-CR groups. Receiver operating characteristic (ROC) curves were used to verify diagnostic performance.

RESULTS

Patients with higher T-stage esophageal cancer might present with poorer response. After CRT, the Ktrans and Kep values significantly decreased in the CR group, whereas only Kep value decreased in the non-CR group. The post-Ktrans and post-Kep values were observed to be significantly lower in the CR group than in the non-CR group. The absolute change and ratio of change of both Ktrans and Kep were higher in the CR group than in the non-CR group. Based on ROC analysis, the ratio of change in Ktrans was the best parameter to assess treatment response (AUC= 0.840).

CONCLUSION

DCE-MRI parameters are valuable in predicting and assessing concurrent CRT response for advanced esophageal cancer.

Tuberculosis of the parotid lymph nodes: clinical and imaging features

Objectives

To characterize clinical, computed tomography (CT) and magnetic resonance imaging (MRI) features of tuberculosis (TB) of the parotid nodes.

Materials and methods

CT (n=21) and MR (n=7) images, and clinical data from 25 patients with TB of the parotid nodes were retrospectively analyzed by two experienced radiologists who reached consensus.

Results

Younger patients (aged <50 years) accounted for 72%. Eighty percent of patients were asymptomatic, and had no history of TB exposure. According to clinical and imaging findings, 64% and 60% patients were misdiagnosed as having tumors, respectively. A total of 43 lesions were identified. Thirty-eight (88.4%) lesions involved the superficial lobe. Fourteen (56%) cases had multiple lesions. There were four types of changes in the parotid fascia: local thickening (40%, n=10); local rupture with thickened adjacent skin (28%, n=7); focal bulge (20%, n=5); and no changes (12%, n=3). Cervical lymphadenopathy was seen in 14 out of 25 cases (56%). The lesions were contrast-enhanced in four patterns on CT images: homogeneous enhancement (37.1%, n=13), irregular cyst-like enhancement (37.1%, n=13), thick-walled ring enhancement (14.2%, n=5), and garland-like enhancement (11.4%, n=4). On MRI, the signal intensity of lesions was isointense on T1-weighted image, hyperintense on T2-weighted image, markedly hyperintense on diffusion-weighted imaging, and low on the apparent diffusion coefficient map. The surrounding parotid parenchymal edema was identified clearly on coronal MR images.

Conclusion

TB of the parotid nodes tend to simulate tumors clinically and radiologically. Their preferential sites are the superficial lobe. In young patients with positive purified protein derivative skin test and lesions accompanied by cervical lymphadenopathy, changes in the parotid fascia and parotid parenchymal edema adjacent to the lesions on CT and MRI may be helpful in the diagnosis and to facilitate differential diagnosis.