Head and neck squamous cell carcinoma: usefulness of diffusion-weighted MR imaging in the prediction of a neoadjuvant therapeutic effect

Does Diffusion Magnetic Resonance Imaging (DWI) has Role in Irradiated Laryngeal Carcinoma?

DWI involves acquisition of signal of movement of water proton in cellular spaces of body (Brownian motion). It includes qualitative method either restricted or facilitated and quantitive method which is apparent diffusion coefficient value(ADC) which is related to proportion of extracellular and intracellular components of the tissue., ADC is calculated with use of at least two b value more accurate using more DWI with different b value,ADC levels is low in increased tissue cellularity, as malignancy., ADC levels is high in non-tumoral tissue alterations such as direct endoscopy oedema, radiotherapy necrosis are expected to have minimal cellularity. ADC is most accurate in the detection of malignancy versus tissue edema or radionecrosis the aim of study to assess value of ADC as regarding measuring sensitivity and specificity and accuracy to differentiate tumor recurrence from radionecrosis. This study includes 36 patients who were suspected patients of tumor recurrence after radiotherapy; it is a prospective randomized comparative clinical trial. The patients were assessed using direct laryngoscopic examination under general anaesthesia and biopsy, and diffusion weighted image on the neck (b0 and b1000), ADC map and ADC value measured al lesion and normal tissues and compared with pathology results. ADC value (mean 0.93 ± 0.30 X 10-3 mm2/s) in patients had recurrent carcinoma was significantly lower (P < .0001) than the mean ADC of normal tissue in the same patients (1.26 ± 0.134) while mean ADC of tumour recurrence (P < .0001) was lower than mean ADC value of radio necrosis (1.63 ± 0.21 × 10-3 mm2/s). MRI ADC value is a sensitive and non-invasive method in detection of a recurrent laryngeal lesion from radionecrosis.

Imaging of human papilloma virus associated oropharyngeal squamous cell carcinoma and its impact on diagnosis, prognostication, and response assessment

The clinical behaviour and outcomes of patients with oropharyngeal cancer (OPC) may be dichotomised according to their association with human papilloma virus (HPV) infection. Patients with HPV-associated disease (HPV+OPC) have a distinct demographic profile, clinical phenotype and demonstrate considerably better responses to chemoradiotherapy. This has led to a reappraisal of staging and treatment strategies for HPV+OPC, which are underpinned by radiological data. Structural modalities, such as CT and MRI can provide accurate staging information. These can be combined with ultrasound-guided tissue sampling and functional techniques (such as diffusion-weighted MRI and 18F-fludeoxyglucose positron emission tomography-CT) to monitor response to treatment, derive prognostic information, and to identify individuals who might benefit from intensification or deintensification strategies. Furthermore, advanced MRI techniques, such as intravoxel incoherent motion and perfusion MRI as well as application of artificial intelligence and radiomic techniques, have shown promise in treatment response monitoring and prognostication. The following review will consider the contemporary role and knowledge on imaging in HPV+OPC.

Neoadjuvant Chemoradiotherapy for Oral Cavity Cancer: Predictive Factors for Response and Interim Analysis of the Prospective INVERT-Trial

Background

To study neoadjuvant chemoradiotherapy (nCRT) and potential predictive factors for response in locally advanced oral cavity cancer (LA-OCC).

Methods

The INVERT trial is an ongoing single-center, prospective phase 2, proof-of-principle trial. Operable patients with stage III-IVA squamous cell carcinomas of the oral cavity were eligible and received nCRT consisting of 60 Gy with concomitant cisplatin and 5-fluorouracil. Surgery was scheduled 6-8 weeks after completion of nCRT. Explorative, multiplex immunohistochemistry (IHC) was performed on pretreatment tumor specimen, and diffusion-weighted magnetic resonance imaging (DW-MRI) was conducted prior to, during nCRT (day 15), and before surgery to identify potential predictive biomarkers and imaging features. Primary endpoint was the pathological complete response (pCR) rate.

Results

Seventeen patients with stage IVA OCC were included in this interim analysis. All patients completed nCRT. One patient died from pneumonia 10 weeks after nCRT before surgery. Complete tumor resection (R0) was achieved in 16/17 patients, of whom 7 (41%, 95% CI: 18-67%) showed pCR. According to the Clavien-Dindo classification, grade 3a and 3b complications were found in 4 (25%) and 5 (31%) patients, respectively; grade 4-5 complications did not occur. Increased changes in the apparent diffusion coefficient signal intensities between MRI at day 15 of nCRT and before surgery were associated with better response (p=0.022). Higher abundances of programmed cell death protein 1 (PD1) positive cytotoxic T-cells (p=0.012), PD1+ macrophages (p=0.046), and cancer-associated fibroblasts (CAFs, p=0.036) were associated with incomplete response to nCRT.

Conclusion

nCRT for LA-OCC followed by radical surgery is feasible and shows high response rates. Larger patient cohorts from randomized trials are needed to further investigate nCRT and predictive biomarkers such as changes in DW-MRI signal intensities, tumor infiltrating immune cells, and CAFs.

Establishment and Validation of a Novel MRI Radiomics Feature-Based Prognostic Model to Predict Distant Metastasis in Endemic Nasopharyngeal Carcinoma

Purpose

We aimed to establish a prognostic model based on magnetic resonance imaging (MRI) radiomics features for individual distant metastasis risk prediction in patients with nasopharyngeal carcinoma (NPC).

Methods

Regression analysis was applied to select radiomics features from T1-weighted (T1-w), contrast-enhanced T1-weighted (T1C-w), and T2-weighted (T2-w) MRI scans. All prognostic models were established using a primary cohort of 518 patients with NPC. The prognostic ability of the radiomics, clinical (based on clinical factors), and merged prognostic models (integrating clinical factors with radiomics) were identified using a concordance index (C-index). Models were tested using a validation cohort of 260 NPC patients. Distant metastasis-free survival (DMFS) were calculated by using the Kaplan-Meier method and compared by using the log-rank test.

Results

In the primary cohort, seven radiomics prognostic models showed similar discrimination ability for DMFS to the clinical prognostic model (P=0.070-0.708), while seven merged prognostic models displayed better discrimination ability than the clinical prognostic model or corresponding radiomics prognostic models (all P&lt;0.001). In the validation cohort, the C-indices of seven radiomics prognostic models (0.645-0.722) for DMFS prediction were higher than in the clinical prognostic model (0.552) (P=0.016 or &lt;0.001) or in corresponding merged prognostic models (0.605-0.678) (P=0.297 to 0.857), with T1+T1C prognostic model (based on Radscore combinations of T1 and T1C Radiomics models) showing the highest C-index (0.722). In the decision curve analysis of the validation cohort for all prognostic models, the T1+T1C prognostic model displayed the best performance.

Conclusions

Radiomics models, especially the T1+T1C prognostic model, provided better prognostic ability for DMFS in patients with NPC.

Correlations between DW-MRI and 18 F-FDG PET/CT parameters in head and neck squamous cell carcinoma following definitive chemo-radiotherapy

BACKGROUND

Posttreatment diffusion-weighted magnetic resonance imaging (DW-MRI) and 18F-fluorodeoxygluocose (18 F-FDG) positron emission tomography (PET) with computed tomography (PET/CT) have potential prognostic value following chemo-radiotherapy (CRT) for head and neck squamous cell carcinoma (HNSCC). Correlations between these PET/CT (standardized uptake value or SUV) and DW-MRI (apparent diffusion coefficient or ADC) parameters have only been previously explored in the pretreatment setting.

AIM

To evaluate stage III and IV HNSCC at 12-weeks post-CRT for the correlation between SUVmax and ADC values and their interval changes from pretreatment imaging.

METHODS

Fifty-six patients (45 male, 11 female, mean age 59.9 + - 7.38) with stage 3 and 4 HNSCC patients underwent 12-week posttreatment DW-MRI and 18 F-FDG PET/CT studies in this prospective study. There were 41/56 patients in the cohort with human papilloma virus-related oropharyngeal cancer (HPV OPC). DW-MRI (ADCmax and ADCmin) and 18 F-FDG PET/CT (SUVmax and SUVmax ratio to liver) parameters were measured at the site of primary tumors (n = 48) and the largest lymph nodes (n = 52). Kendall's tau evaluated the correlation between DW-MRI and 18 F-FDG PET/CT parameters. Mann-Whitney test compared the post-CRT PET/CT and DW-MRI parameters between those participants with and without 2-year disease-free survival (DFS).

RESULTS

There was no correlation between DW-MRI and 18 F-FDG PET/CT parameters on 12-week posttreatment imaging (P = .455-.794; tau = -0.075-0.25) or their interval changes from pretreatment to 12-week posttreatment imaging (P = .1-.946; tau = -0.194-0.044). The primary tumor ADCmean (P = .03) and the interval change in nodal ADCmin (P = .05) predicted 2-year DFS but none of the 18 F-FDG PET/CT parameters were associated with 2-year DFS.

CONCLUSIONS

There is no correlation between the quantitative DWI-MRI and 18 F-FDG PET/CT parameters derived from 12-week post-CRT studies. These parameters may be independent biomarkers however in this HPV OPC dominant cohort, only selected ADC parameters demonstrated prognostic significance. Study was prospectively registered at http://www.controlled-trials.com/ISRCTN58327080.

The impact of human papilloma virus status on the prediction of head and neck cancer chemoradiotherapy outcomes using the pre-treatment apparent diffusion coefficient

Objective:

To determine the impact of Human Papilloma Virus (HPV) oropharyngeal cancer (OPC) status on the prediction of head and neck squamous cell cancer (HNSCC) chemoradiotherapy (CRT) outcomes with pre-treatment quantitative diffusion-weighted magnetic resonance imaging (DW-MRI).

Methods:

Following ethical approval, 65 participants (53 male, age 59.9 ± 7.86) underwent pre-treatment DW-MRI in this prospective cohort observational study. There were 46 HPV OPC and 19 other HNSCC cases with Stage III/IV HNSCC. Regions of interest (ROIs) (volume, largest area, core) at the primary tumour (n = 57) and largest pathological node (n = 59) were placed to analyse ADC_mean and ADC_min. Unpaired t-test or Mann–Whitney test evaluated the impact of HPV OPC status and clinical parameters on their prediction of post-CRT 2 year locoregional and disease-free survival (LRFS and DFS). Multivariate logistic regression compared significant variables with 2 year outcomes.

Results:

On univariate analysis of all participants, the primary tumour area ADC_mean was predictive of 2 year LRFS (p = 0.04). However, only the HPV OPC diagnosis (LFRS p = 0.03; DFS p = 0.02) predicted outcomes on multivariate analysis. None of the pre-treatment ADC values were predictive of 2 year DFS in the HPV OPC subgroup (p = 0.21–0.68). Amongst participants without 2 year disease-free survival, HPV-OPC was found to have much lower primary tumour ADC_mean values than other HNSCC.

Conclusion:

Knowledge of HPV OPC status is required in order to determine the impact of the pre-treatment ADC values on post-CRT outcomes in HNSCC.

Advances in knowledge:

Pre-treatment ADC_mean and ADC_min values acquired using different ROI methods are not predictive of 2 year survival outcomes in HPV OPC.

A Nomogram for Pretreatment Prediction of Response to Induction Chemotherapy in Locally Advanced Hypopharyngeal Carcinoma

BACKGROUND

Induction chemotherapy (IC) significantly improves the rate of larynx preservation; however, some patients could not benefit from it. Hence, it is of clinical importance to predict the response to IC to determine the necessity of IC. We aimed to develop a clinical nomogram for predicting the treatment response to IC in locally advanced hypopharyngeal carcinoma.

METHODS

We retrospectively include a total of 127 patients with locally advanced hypopharyngeal carcinoma who underwent MRI scans prior to IC between January 2014 and December 2017. The clinical characteristics were collected, which included age, sex, tumor location, invading sites, histological grades, T-stage, N-stage, overall stage, size of the largest lymph node, neutrophil-to-lymphocyte ratio, hemoglobin concentration, and platelet count. Univariate and multivariate logistic regression was used to select the significant predictors of IC response. A nomogram was built based on the results of stepwise logistic regression analysis. The predictive performance and clinical usefulness of the nomogram were determined based on the area under the curve (AUC), calibration curve, and decision curve.

RESULTS

Age, T-stage, hemoglobin, and platelet were four independent predictors of IC treatment response, which were incorporated into the nomogram. The AUC of the nomogram was 0.860 (95% confidence interval [CI]: 0.780-0.940), which was validated using 3-fold cross-validation (AUC, 0.864; 95% CI: 0.755-0.973). The calibration curve demonstrated good consistency between the prediction by the nomogram and actual observation. Decision curve analysis shows that the nomogram was clinically useful.

CONCLUSION

The proposed nomogram resulted in an accurate prediction of the efficacy of IC for patients with locally advanced hypopharyngeal carcinoma.

Optimization of Simultaneous Multislice, Readout-Segmented Echo Planar Imaging for Accelerated Diffusion-Weighted Imaging of the Head and Neck: A Preliminary Study

RATIONALE AND OBJECTIVES

To evaluate the feasibility of simultaneous multislice (SMS)-accelerated, readout-segmented echo-planar imaging (rs-EPI, RESOLVE) with the use of special-purpose coils for head and neck assessment, particularly in patients diagnosed with head and neck malignant tumors, through comparison with the conventional RESOLVE and RESOLVE with readout partial-Fourier technique (RESOLVE-RPF).

MATERIALS AND METHODS

Twenty-five healthy volunteers and 24 patients with histologically proven malignant head and neck tumors were included in this prospective study. The MR exam included conventional RESOLVE, RESOLVE-RPF, prototypic SMS-RESOLVE, and prototypic SMS-RESOLVE with special-purpose coils (SMS-RESOLVE + Coils), acquired at b-values of both 0 and 800 s/mm². Image quality was evaluated qualitatively (reader score) and quantitatively (tumor distortion, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), SNR efficiency) and compared. For volunteer imaging, the image quality of target tissues at three different typical levels (oropharyngeal, hypopharyngeal, and thyroid level) were evaluated. For patient imaging, the image quality of primary tumors and metastatic lymph nodes was evaluated.

RESULTS

The acquisition time was 3:37 minutes for RESOLVE, 2:58 minutes for RESOLVE-RFP, 2:01 minutes for SMS-RESOLVE and 2:01 minutes for SMS-RESOLVE + Coils, with a 44% reduction compared to the conventional RESOLVE. No significant differences in the reader scores, tumor distortion, or ADC values of the lesions were found among the protocols. The SNR and CNR at the oropharyngeal and hypopharyngeal level of SMS-RESOLVE + Coils were markedly improved and significantly higher than those of RESOLVE, as well as the SNR, SNR efficiency of tumors and lymph nodes. No significant differences in quantitative measurements were found at the thyroid level.

CONCLUSION

SMS-RESOLVE + Coils protocol is an effective and promising approach to optimally reducing the total acquisition time, and could be a good alternative with a superior SNR and SNR efficiency in comparison with conventional RESOLVE. However, the limited application in the lower neck region needs further investigation.

Usefulness of diffusion-weighted magnetic resonance imaging for evaluating the effect of hemostatic radiotherapy for unresectable gastric cancer

There are several reports that vouch for the usefulness of diffusion-weighted image (DWI) in making a diagnosis before treatment. However, no study has evaluated the effect of radiotherapy (RT) for unresectable gastric cancer. In the present case report, we evaluated the effectiveness of RT using DWI. An 81-year-old man was hospitalized with a broken bone and then diagnosed with advanced gastric cancer with breeding. He had chorionic renal failure and surgery was impossible. Further, contrast-enhanced computed tomography and magnetic resonance imaging (MRI) were not performed due to renal failure, whereas palliative RT was performed. We followed up the patient using blood test and MRI (DWI) to estimate whether bleeding had stopped or not after radiotherapy. Hemostasis effect was found after 2 weeks of RT. In DWI examination, there was a decrease in the tumor signal intensity 30 days after RT. Similarly, at day 60, the tumor signal intensity further decreased on DWI and the blood test results indicated no progression of anemia. At 4 months after the RT, the patient died because of respiratory failure without any bleeding. DWI is useful not only for the initial diagnosis but also for evaluating the effectiveness of RT.Trial registration: National clinical study registered number: UMIN000026362.

Functional magnetic resonance imaging of head and neck cancer: Performance and potential

Functional magnetic resonance imaging (MRI) of tumors of the head and neck usually encompasses diffusion-weighted imaging (DWI) and intravenous (IV) contrast T1 dynamic perfusion imaging (DCE-MRI or PWI). Both techniques can characterize different tissues by probing into their microstructure, providing a novel approach in oncological imaging. In this pictorial review, we will cover the important technical aspects of DWI and PWI, the pathophysiological background and the current applications and potential of these functional MRI techniques in the imaging of head and neck cancer.

Dynamic contrast-enhanced magnetic resonance imaging for pretreatment prediction of early chemo-radiotherapy response in larynx and hypopharynx carcinoma

Purpose

This study is to investigate the use of dynamic contrast-enhanced magnetic resonance imaging in predicting early response to CRT (chemo-radiotherapy) in patients with larynx and hypopharynx carcinoma from primary tumors.

Method

Sixty-two patients with larynx and hypopharynx carcinoma underwent two DCE-MRI studies: a baseline exam before any treatmentanda post-treatment exam 3 weeks after CRT. At the end of treatment, patients were classified as responders, or non-responders according to the Response Evaluation Criteria in Solid Tumors criteria (RECIST). The time intensity curves (TIC) were extracted and processed to obtain time to peak (TTP), maximum slope of increase (MSI), maximum slope of decrease (MSD) and positive enhancement integral (PEI), and the semi-quantitative MRI parameters were compared and analyzed between the two groups.

Results

Fifty-four and 8 patients were included the responder and non-responder groups. It was observed that the MSI, MSD, and PEI were significantly lower post-treatment than pre-treatment(P < 0.05). The pretreatment MSI, MSD, and PEI parameters of responders were significantly higher than those of non-responders (P< 0.05). The post-treatment MSI, MSD, and PEI parameters of responders were significantly lower than those of non-responders (P< 0.05). Based on ROC curve analysis, at a threshold of 154.81 for pretreatment MSI, the corresponding AUC, sensitivity, and specificity were 0.882, 89.3% and 73.5%, respectively.

Conclusion

The semi-quantitative DCE-MRI may aid in the prediction of early response to CRT in patients with larynx and hypopharynx carcinoma.

The emerging potential of magnetic resonance imaging in personalizing radiotherapy for head and neck cancer: an oncologist's perspective

Head and neck cancer (HNC) is a challenging tumour site for radiotherapy delivery owing to its complex anatomy and proximity to organs at risk (OARs) such as the spinal cord and optic apparatus. Despite significant advances in radiotherapy planning techniques, radiation-induced morbidities remain substantial. Further improvement would require high-quality imaging and tailored radiotherapy based on intratreatment response. For these reasons, the use of MRI in radiotherapy planning for HNC is rapidly gaining popularity. MRI provides superior soft-tissue contrast in comparison with CT, allowing better definition of the tumour and OARs. The lack of additional radiation exposure is another attractive feature for intratreatment monitoring. In addition, advanced MRI techniques such as diffusion-weighted, dynamic contrast-enhanced and intrinsic susceptibility-weighted MRI techniques are capable of characterizing tumour biology further by providing quantitative functional parameters such as tissue cellularity, vascular permeability/perfusion and hypoxia. These functional parameters are known to have radiobiological relevance, which potentially could guide treatment adaptation based on their changes prior to or during radiotherapy. In this article, we first present an overview of the applications of anatomical MRI sequences in head and neck radiotherapy, followed by the potentials and limitations of functional MRI sequences in personalizing therapy.

Diffusion MRI in early cancer therapeutic response assessment

Imaging biomarkers for the predictive assessment of treatment response in patients with cancer earlier than standard tumor volumetric metrics would provide new opportunities to individualize therapy. Diffusion-weighted MRI (DW-MRI), highly sensitive to microenvironmental alterations at the cellular level, has been evaluated extensively as a technique for the generation of quantitative and early imaging biomarkers of therapeutic response and clinical outcome. First demonstrated in a rodent tumor model, subsequent studies have shown that DW-MRI can be applied to many different solid tumors for the detection of changes in cellularity as measured indirectly by an increase in the apparent diffusion coefficient (ADC) of water molecules within the lesion. The introduction of quantitative DW-MRI into the treatment management of patients with cancer may aid physicians to individualize therapy, thereby minimizing unnecessary systemic toxicity associated with ineffective therapies, saving valuable time, reducing patient care costs and ultimately improving clinical outcome. This review covers the theoretical basis behind the application of DW-MRI to monitor therapeutic response in cancer, the analytical techniques used and the results obtained from various clinical studies that have demonstrated the efficacy of DW-MRI for the prediction of cancer treatment response. Copyright © 2016 John Wiley & Sons, Ltd.

Predictive value of pre-treatment apparent diffusion coefficient (ADC) in radio-chemiotherapy treated head and neck squamous cell carcinoma

OBJECTIVE

This study aimed at evaluating the role of "baseline" apparent diffusion coefficent (ADC), in patients affected by head and neck cancer treated with radio-chemotherapy, as a potential marker of response to therapy.

METHODS

Fifty-seven patients underwent pretreatment ADC maps. Minimum, maximum, and medium ADC were computed. Age, dose, treatment time, and ADC values were compared between the two groups (Group 1: local control; Group 2: relapse/persistence of disease) using the Student t test two-tailed unpaired. Two-tailed Fischer exact test was used to compare T stage, N stage, grading and type of treatment between two groups. We have analyzed the receiver operating characteristic (ROC) of statistically significant variables.

RESULTS

In patients with local control, values of pre-treatment medium and minimum ADC were lower than ADC values of patients with persistent or recurrent disease, with values, respectively, of 0.83 ± 0.02 × 10^-3 mm²/s and 0.59 ± 0.02 × 10^-3 mm²/s (vs 0.94 ± 0.05 × 10^-3 mm²/s and 0.70 ± 0.05 × 10^-3 mm²/s). ROC curve analysis displayed statistical significance as regarding the medium ADC value, showing a sensitivity of 50% and a specificity of 84.8%. ROC analysis of the values minimum ADC showed a sensitivity of 42.9% and specificity of 87.9%.

CONCLUSION

The value of the ADC pre-treatment of patients with local control of the disease is lower than that of patients with persistent disease or recurrence.

The Predictive Value of Early Assessment After 1 Cycle of Induction Chemotherapy with 18F-FDG PET/CT and Diffusion-Weighted MRI for Response to Radical Chemoradiotherapy in Head and Neck Squamous Cell Carcinoma

The objective of this study was to assess the predictive value of early assessment (after 1 cycle of induction chemotherapy [IC]) with 18F-FDG PET/CT and diffusion-weighted (DW) MRI for subsequent response to radical chemoradiotherapy in locally advanced head and neck squamous cell carcinoma (HNSCC).

METHODS

Twenty patients with stage III-IVa HNSCC prospectively underwent 18F-FDG PET/CT and DW MRI before and 2 wk after each cycle of IC (first cycle, IC1; second cycle, IC2). Response was assessed 3 mo after completion of chemoradiotherapy with clinical examination, MRI, and 18F-FDG PET/CT. Patients with persistent disease were classed as nonresponders. Changes in functional and molecular imaging parameters after IC1 were compared between responders and nonresponders with the Mann-Whitney U test. The significance threshold was set at a P value of less than 0.05.

RESULTS

Responders showed a significantly greater reduction in metabolic tumor volume (P = 0.03) and total lesion glycolysis (P = 0.04) after IC1 than nonresponders. Responders also showed a tendency toward a larger but statistically nonsignificant increase in apparent diffusion coefficient after IC1. There was no significant difference in the changes from baseline between the IC1 and IC2 for all functional and molecular imaging parameters, indicating that most biologic response to IC measured by 18F-FDG PET/CT and DW MRI was observed early after the first cycle of IC.

CONCLUSION

Our preliminary data indicate that the 18F-FDG PET/CT-derived metabolic tumor volume or total lesion glycolysis, acquired after IC1, are early predictive biomarkers for ultimate response to subsequent chemoradiotherapy. These early biomarkers enable identification of patients at risk of treatment failure at an early time point, permitting treatment individualization and consideration of alternative strategies such as radiotherapy dose escalation or surgery.

Squamous cell carcinoma of the oral cavity and oropharynx: what does the apparent diffusion coefficient tell us about its histology?

Background Diffusion-weighted imaging obtained with magnetic resonance (DW-MRI) is a non-invasive imaging tool potentially able to provide information about microstructural tumor characteristics. Purpose To prospectively analyze the correlation between the apparent diffusion coefficient (ADC) and clinical-histologic characteristics of squamous cell carcinoma (SCCA) of the oral cavity and oropharynx. Material and Methods Sixty-seven patients with untreated, histologically proven SCCA of the oral cavity and oropharynx underwent conventional and diffusion-weighted (b-values 0, 50, 250, 500, and 900 s/mm²) MRI. Tumor ADC was calculated from regions of interest drawn manually on the highest b-value images using ImageJ (ImageJ, NIH) and fsl (fsl 4, University of Oxford) image processing packages. ADC was calculated in two ways: standard ADC using all b-values; and ADC^High using only b-values ≥ 250 s/mm². We assessed the correlations between both ADC and ADC^High and the clinical-histological characteristics of SCCA. Results Fifty-two patients (36 men, 16 women; mean age, 55 ± 13 years) were suitable for ADC calculation. Mean ADC was 1136.0 ± 108.5 × 10^-6mm²/s. Mean tumor ADC^High was 991.2 ± 152.1 × 10^-6mm²/s. Mean tumor size was 32.3 ± 13.4 mm (range, 14.0-69.0 mm). We observed no correlation of either ADC or ADC^High values with any of the clinical-histological tumor characteristics. Undifferentiated tumors (G3) showed lower apparent diffusion coefficient values compared to differentiated ones (G1-G2), without reaching statistical significance. Conclusion We did not observe any statistically significant correlation between ADC values and clinical-histological characteristics of SCCA of the oral cavity and oropharynx.

Characterization of cervical lymph-nodes using a multi-parametric and multi-modal approach for an early prediction of tumor response to chemo-radiotherapy

PURPOSE

In the treatment of Head-and-Neck Squamous Cell Carcinoma (HNSCC), the early prediction of residual malignant lymph nodes (LNs) is currently required. Here, we investigated the potential of a multi-modal characterization (combination of CT, T2w-MRI and DW-MRI) at baseline and at mid-treatment, based on texture analysis (TA), for the early prediction of LNs response to chemo-radiotherapy (CRT).

METHODS

30 patients with pathologically confirmed HNSCC treated with CRT were considered. All patients underwent a planning CT and two serial MR examinations (including T2w and DW images), one before and one at mid-CRT. For each patient the largest malignant LN was selected and within each LN, morphological and textural features were estimated from T2w-MRI and CT, besides a quantification of the apparent diffusion coefficient (ADC) from DW-MRI. After a median follow-up time of 26.6months, 19 LNs showed regional control, while 11 LNs showedregional failure at a median time of 4.6months. Linear discriminant analysis was used to test the accuracy of the image-based features in predicting the final response.

RESULTS

Pre-treatment features showed higher predictive power than mid-CRT features, the ADC having the highest accuracy (80%); CT-based indices were found not predictive. When ADC was combined with TA, the classification performance increased (accuracy=82.8%). If only T2w-MRI features were considered, the best combination of pre-CRT indices and their variation reached an equivalent accuracy (81.8%).

CONCLUSION

Our results may suggest that TA on T2w-MRI and ADC can be combined together to obtain a more accurate prediction of response to CRT.

Pretreatment Intra-Voxel Incoherent Motion Diffusion-Weighted Imaging (IVIM-DWI) in Predicting Induction Chemotherapy Response in Locally Advanced Hypopharyngeal Carcinoma

The aim of this study was to predict response to induction chemotherapy in patients with locally advanced hypopharyngeal carcinoma by IVIM values.Twenty-eight patients with locally advanced hypopharyngeal carcinoma underwent IVIM studies using 12 different b values (b = 0, 10, 20, 30, 50, 70 100, 150, 200, 400, 800, and 1000 s/ mm). All patients underwent 2 MRI studies: a baseline exam before any treatment and a mid-treatment exam 3 weeks after induction chemotherapy. In the IVIM approach, D, f, and D were extracted from a bi-exponential fit. For comparison, the ADC map were extracted from a mono-exponential fit. At the end of induction chemotherapy, patients were classified as responders or nonresponders group according to the Response Evaluation Criteria in Solid Tumors criteria (RECIST), based on their MRI measurement. The patients were classified into high grade group (G1), moderate grade group (G2), and low grade group (G3) according to the tumor pathological grading. The predictive value of IVIM parameters were examined with Student's t test, analysis of variance (ANOVA), and receiver operating characteristic (ROC) curves.After 2 cycles of induction chemotherapy, 18 patients were categorized into the responder group whereas the other 10 patients were considered nonresponders. Compared with the pretreatment value, the post-treatment ADC value and D value was significantly higher and the posttreatment D value was significantly lower (all P <  0.05). In contrast, post-treatment f parameter only changed slightly (P > 0.05). Compared with nonresponders, a notably lower pretreatment ADC value, D value, posttreatment D value, and higher posttreatment ADC value, D value, ΔADC, ΔD, and ΔD were observed in responders (all P < 0.05), but no significant change in Δ f among the 2 group (P > 0.05). The ROC curve analysis indicated that the cutoff of pretreatment D value in best predicting tumor's chemotherapeutic response was 0.847 × 10 mm/s, and the corresponding AUC, sensitivity, and specificity were 0.806, 75.0%, and 88.9%, respectively. Although pretreatment IVIM-derived parameters had no significant differences between high grade, moderate grade, and low grade group, a trend towards lower D was observed with increasing tumor grading from G3 to G1.IVIM-DWI can potentially predict the treatment response to induction chemotherapy for hypopharyngeal carcinoma.

Diffusion-Weighted MRI in the Assessment of Early Treatment Response in Patients with Squamous-Cell Carcinoma of the Head and Neck: Comparison with Morphological and PET/CT Findings

OBJECTIVE

To evaluate changes in apparent diffusion coefficients (ADC) as measured by magnetic resonance imaging (MRI) before and after the treatment of primary tumors and cervical metastases in patients with squamous-cell carcinoma (SCC) of the head and neck, and to compare these values to the results of widely used morphological criteria and [18F]-FDG PET/CT findings.

MATERIAL AND METHOD

This was a longitudinal, prospective, single-center nonrandomized trial involving patients with head and neck SCC treated with chemotherapy alone or in combination with radiotherapy. Imaging examinations ([18F]-FDG PET/CT and diffusion-weighted MRI) were performed on the same day, up to one day prior to the beginning of the first treatment cycle, and on the 14th day of the first chemotherapy cycle. Treatment response was evaluated based on the Response Evaluation Criteria in Solid Tumors (RECIST) and World Health Organization (WHO) morphological criteria, as well as PET Response Criteria in Solid Tumors (PERCIST) metabolic criteria.

RESULTS

Seventy-five lesions were examined in 23 patients. Pre- and post-treatment comparisons of data pertaining to all target lesions revealed reductions in tumor size and SUV, as well as increases in ADC values, all of which were statistically significant. The increase in ADC following treatment was significantly higher in patients classified as complete responders by both morphological criteria than that observed in any of the other patient groups of response. Patients with a complete metabolic response also showed greater increases in ADC values as compared to the remaining groups.

CONCLUSION

The assessment of tumor response based on diffusion-weighted MRI showed an increase in the ADC of cervical lesions following treatment, which was corroborated by morphological and metabolic findings. Associations between changes in ADC values and treatment response categories using morphologic criteria and [18F]-FDG PET/CT were only identified in complete responders.

Squamous Cell Carcinoma of the Head and Neck: Comparison of Diffusion-weighted MRI at b-values of 1,000 and 2,000 s/mm(2) to Predict Response to Induction Chemotherapy

PURPOSE

Recent publications have reported contradictory results of pretreatment diffusion-weighted magnetic resonance imaging (DWI) for the prediction of chemoradiotherapeutic response in primary squamous cell carcinomas of the head and neck (HNSCC). Therefore, we evaluated the diagnostic performance of DWI obtained with both standard (b = 0 and 1,000 s/mm²) and high (b = 0 and 2,000 s/mm²) b-values for predicting response to induction chemotherapy in HNSCCs.

METHODS

For 25 patients with primary HNSCC who underwent DWI with both standard and high b-values prior to treatment, we calculated corresponding apparent diffusion coefficient (ADC) maps. Regions of interest containing the tumor were drawn on every section of ADC maps and summated to make volume-based data of the entire tumor. Histogram parameters (mean ADC, kurtosis, and skewness) were correlated with treatment response using unpaired Student t test. Univariate and multivariate analysis of the ADC parameters, patient age, sex, whole tumor volume, and T stage were also performed to predict tumor response to induction chemotherapy.

RESULTS

Response to induction chemotherapy was good in 13 of the 25 patients and poor in 12. The mean ADC values of good responders at standard b-value (ADC1000), 1.23 ± 0.34 (× 10⁻³ mm²/s), and high b-value (ADC2000), 0.62 ± 0.14 (× 10⁻³ mm²/s), were lower than those of poor responders (ADC1000, 1.32 ± 0.28 [× 10⁻³ mm²/s]; ADC2000, 0.76 ± 0.15 [× 10⁻³ mm²/s]), but significant difference was achieved only at the ADC2000 map (P = 0.02). In addition, mean tumor volume prior to treatment of good responders was smaller than that of poor responders. However, at multiple logistic regression analysis, only the mean ADC2000 value remained as a significant predictor of response to induction chemotherapy.

CONCLUSION

DWI with high b-values (b = 0 and 2,000 s/mm²) as an assessment of ADC values may help predict tumor response to neoadjuvant chemotherapy for primary HNSCCs.

Diagnosis of Peritoneal Metastases with Abdominal Malignancies: Role of ADC Measurement on Diffusion Weighted MRI

OBJECTIVE

The purpose of our study was to evaluate the utility of the apparent diffusion coefficient (ADC) value measurement in the diagnosis of peritoneal metastases on diffusion weighted magnetic resonance imaging.

MATERIALS AND METHODS

Diffusion weighted imaging with conventional magnetic resonance imaging sequences was performed on twenty consecutive oncology patients (group I) with peritoneal metastases. The ADC values of the metastases, the peritoneal fat around the metastases (group I) and the peritoneal fat in patients with no malignancy (group II) at b(0-100), b(0-600), and (b 0-1000) s/mm(2) gradients were measured and compared.

RESULTS

The apparent diffusion coefficient values of three gradients in peritoneal metastases (2.27±0.4; 1.67±0.7 and 1.09±0.4×10(-3) mm(2)/s at b 100, 600 and 1000 gradients, respectively) were significantly lower than the ADC values of the peritoneal fat around metastases (3.07±0.4; 2.07±0.4; 1.33±0.3×10(-3) mm(2)/s at b 100, 600 and 1000 gradients, respectively) (p<0.05). There was no significant difference between the ADC values of peritoneal fat in the patients of group I and group II at the 3 diffusion gradients (p>0.05).

CONCLUSION

The measurement of ADC values may be used as a complementary diagnostic method in differentiating peritoneal metastases from peritoneal fat on Diffusion Weighted MRI (DWMRI DWMRI).

Toward adaptive radiotherapy for head and neck patients: Feasibility study on using CT-to-CBCT deformable registration for "dose of the day" calculations

PURPOSE

The aim of this study was to evaluate the appropriateness of using computed tomography (CT) to cone-beam CT (CBCT) deformable image registration (DIR) for the application of calculating the "dose of the day" received by a head and neck patient.

METHODS

NiftyReg is an open-source registration package implemented in our institution. The affine registration uses a Block Matching-based approach, while the deformable registration is a GPU implementation of the popular B-spline Free Form Deformation algorithm. Two independent tests were performed to assess the suitability of our registrations methodology for "dose of the day" calculations in a deformed CT. A geometric evaluation was performed to assess the ability of the DIR method to map identical structures between the CT and CBCT datasets. Features delineated in the planning CT were warped and compared with features manually drawn on the CBCT. The authors computed the dice similarity coefficient (DSC), distance transformation, and centre of mass distance between features. A dosimetric evaluation was performed to evaluate the clinical significance of the registrations errors in the application proposed and to identify the limitations of the approximations used. Dose calculations for the same intensity-modulated radiation therapy plan on the deformed CT and replan CT were compared. Dose distributions were compared in terms of dose differences (DD), gamma analysis, target coverage, and dose volume histograms (DVHs). Doses calculated in a rigidly aligned CT and directly in an extended CBCT were also evaluated.

RESULTS

A mean value of 0.850 in DSC was achieved in overlap between manually delineated and warped features, with the distance between surfaces being less than 2 mm on over 90% of the pixels. Deformable registration was clearly superior to rigid registration in mapping identical structures between the two datasets. The dose recalculated in the deformed CT is a good match to the dose calculated on a replan CT. The DD is smaller than 2% of the prescribed dose on 90% of the body's voxels and it passes a 2% and 2 mm gamma-test on over 95% of the voxels. Target coverage similarity was assessed in terms of the 95%-isodose volumes. A mean value of 0.962 was obtained for the DSC, while the distance between surfaces is less than 2 mm in 95.4% of the pixels. The method proposed provided adequate dose estimation, closer to the gold standard than the other two approaches. Differences in DVH curves were mainly due to differences in the OARs definition (manual vs warped) and not due to differences in dose estimation (dose calculated in replan CT vs dose calculated in deformed CT).

CONCLUSIONS

Deforming a planning CT to match a daily CBCT provides the tools needed for the calculation of the "dose of the day" without the need to acquire a new CT. The initial clinical application of our method will be weekly offline calculations of the "dose of the day," and use this information to inform adaptive radiotherapy (ART). The work here presented is a first step into a full implementation of a "dose-driven" online ART.

Predictive value of diffusion-weighted imaging without and with including contrast-enhanced magnetic resonance imaging in image analysis of head and neck squamous cell carcinoma

OBJECTIVES

To assess disease-free survival (DFS) in head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy ([C]RT).

METHODS

Pretreatment MR-images of 78 patients were retrospectively studied. Apparent diffusion coefficients (ADC) were calculated with two sets of two b-values: 0-750s/mm(2) (ADC750) and 0-1000s/mm(2) (ADC1000). One observer assessed tumor volume on T1-WI. Two independent observers assessed ADC-values of primary tumor and largest lymph node in two sessions (i.e. without and with including CE-T1WI in image analysis). Interobserver and intersession agreement were assessed with intraclass correlation coefficients (ICC) separately for ADC750 and ADC1000. Lesion volumes and ADC-values were related to DFS using Cox regression analysis.

RESULTS

Median follow-up was 18 months. Interobserver ICC was better without than with CE-T1WI (primary tumor: 0.92 and 0.75-0.83, respectively; lymph node: 0.81-0.83 and 0.61-0.64, respectively). Intersession ICC ranged from 0.84 to 0.89. With CE-T1WI, mean ADC-values of primary tumor and lymph node were higher at both b-values than without CE-T1WI (P<0.001). Tumor volume (sensitivity: 73%; specificity: 57%) and lymph node ADC1000 (sensitivity: 71-79%; specificity: 77-79%) were independent significant predictors of DFS without and with including CE-T1WI (P<0.05).

CONCLUSIONS

Pretreatment primary tumor volume and lymph node ADC1000 were significant independent predictors of DFS in HNSCC treated with (C)RT. DFS could be predicted from ADC-values acquired without and with including CE-T1WI in image analysis. The inclusion of CE-T1WI did not result in significant improvements in the predictive value of DWI. DWI without including CE-T1WI was highly reproducible.

Apparent diffusion coefficient is a prognostic factor of head and neck squamous cell carcinoma treated with radiotherapy

PURPOSE

To evaluate the correlation between apparent diffusion coefficient (ADC) and prognosis in head and neck squamous cell carcinoma (HNSCC) treated with radiotherapy.

MATERIALS AND METHODS

We retrospectively studied 41 patients (38 male and 3 female, ages 37-85 years) diagnosed with HNSCC (14 oropharynx, 22 hypopharynx, 4 larynx, 1 oral cavity) and treated with radiotherapy, with radiation dose to gross tumor volume over 60 Gy. The association between age, gender, performance status, tumor location, T stage, N stage, stage, dose, overall treatment time, treatment method, adjuvant therapy, or ADC and prognosis was analyzed using a Cox proportional hazard test.

RESULTS

ADC calculated with b-values of 300, 500, 750, and 1,000 s/mm(2) (ADC 300-1,000) alone showed a significant correlation with all of the analyses (p = 0.022 for local control, p = 0.0109 for regional control, p = 0.0041 for disease-free survival, and p = 0.0014 for overall survival). ADC calculated with b-values of 0, 100, and 200 s/mm(2) (ADC 0-200) showed a significant correlation with overall survival (p = 0.0012). N stage showed a significant correlation with regional control (p = 0.0241). Performance status showed significant association with local control (p = 0.0459), disease-free survival (p = 0.023), and overall survival (p = 0.0151), respectively.

CONCLUSION

ADC is an independent predictor of prognosis in HNSCC treated with radiotherapy.

Fractional change in apparent diffusion coefficient as an imaging biomarker for predicting treatment response in head and neck cancer treated with chemoradiotherapy

BACKGROUND AND PURPOSE

ADC provides a measure of water molecule diffusion in tissue. The aim of this study was to evaluate whether the fractional change in ADC during therapy can be used as a valid predictive indicator of treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy.

MATERIALS AND METHODS

Forty patients underwent DWI at pretreatment and 3 weeks after the start of treatment. The pretreatment ADC, fractional change in ADC, tumor regression rate, and other clinical variables were compared with locoregional control and locoregional failure and were analyzed by using logistic regression analysis and receiver operating characteristic analysis. Furthermore, progression-free survival curves divided by the corresponding threshold value were compared by means of the log-rank test.

RESULTS

The fractional change in ADCprimary, the fractional change in ADCnode, primary tumor volume, nodal volume, tumor regression ratenode, N stage, and tumor location revealed significant differences between locoregional failure and locoregional control (P < .05). In univariate analysis, the fractional change in ADCprimary, fractional change in ADCnode, tumor regression ratenode, N stage, and tumor location showed significant association with locoregional control (P < .05). In multivariate analysis, however, only the fractional change in ADCprimary was identified as a significant and independent predictor of locoregional control (P = .04). A threshold fractional change in ADCprimary of 0.24 revealed a sensitivity of 100%, specificity of 78.7%, and overall accuracy of 84.8% for the prediction of locoregional control. Progression-free survival of the 2 groups divided by the fractional change in ADCprimary at 0.24 showed a significant difference (P < .05).

CONCLUSIONS

The results suggest that the fractional change in ADCprimary is a valid imaging biomarker for predicting treatment response in head and neck squamous cell carcinoma treated with chemoradiotherapy.

Dynamic contrast-enhanced MR imaging predicts local control in oropharyngeal or hypopharyngeal squamous cell carcinoma treated with chemoradiotherapy

The role of pretreatment dynamic contrast-enhanced perfusion MR imaging (DCE-PWI) and diffusion-weighted MR imaging (DWI) in predicting the treatment response of oropharyngeal or hypopharyngeal squamous cell carcinoma (OHSCC) to chemoradiation remains unclear. We prospectively investigated the ability of pharmacokinetic parameters derived from pretreatment DCE-PWI and DWI to predict the local control of OHSCC patients treated with chemoradiation. Between August, 2010 and March, 2012, patients with untreated OHSCC scheduled for chemoradiation were eligible for this prospective study. DCE-PWI and DWI were performed in addition to conventional MRI. The relationship of local control with the following clinical and imaging variables was analyzed: the hemoglobin level, T-stage, tumor location, gross tumor volume, maximum standardized uptake value, metabolic tumor volume and total lesion glycolysis on FDG PET/CT, transfer constant (K^trans), volume of blood plasma and volume of extracellular extravascular space on DCE-PWI, and apparent diffusion coefficient on DWI of the primary tumor. The patients were also divided into a local control group and a local failure group, and their clinical and imaging parameters were compared. There were 58 patients (29 with oropharynx squamous cell carcinoma [SCC] and 29 with hypopharynx SCC) with successful pretreatment DCE-PWI and DWI available for analysis. After a median follow-up of 18.2 months, 17 (29.3%) participants had local failure, whereas the remaining 41 patients achieved local control. Univariate analysis revealed that only the K^trans value was significantly associated with local control (P = 0.03). When the local control and local failure groups were compared, significant differences were observed in K^trans and the tumor location (P = 0.01 and P = 0.04, respectively). In the multivariable analysis, only K^trans was statistically significant (P = 0.04). Our results suggest that pretreatment K^trans may help predict the local control in OHSCC patients treated with chemoradiation.

Comparing primary tumors and metastatic nodes in head and neck cancer using intravoxel incoherent motion imaging: a preliminary experience

OBJECTIVE

This study aimed to use intravoxel incoherent motion (IVIM) imaging for investigating differences between primary head and neck tumors and nodal metastases and to evaluate IVIM efficacy in predicting outcome.

METHODS

Sixteen patients with head and neck cancer underwent IVIM diffusion-weighted imaging on a 1.5-T magnetic resonance imaging scanner. The significance of parametric difference between primary tumors and metastatic nodes were tested. Probabilities of progression-free survival and overall survival were estimated using the Kaplan-Meier method.

RESULTS

In comparison with metastatic nodes, the primary tumors had significantly higher vascular volume fraction (f) (P < 0.0009) and lower diffusion coefficient (D) (P < 0.0002). Patients with lower SD for D had prolonged progression-free survival and overall survival (P < 0.05).

CONCLUSIONS

Pretreatment IVIM measures were feasible in investigating the physiologic differences between the 2 tumor tissues. After appropriate validation, these findings might be useful in optimizing treatment planning and improving patient care.

Value of diffusion-weighted MR imaging performed with quantitative apparent diffusion coefficient values for cervical lymphadenopathy

PURPOSE

To assess diffusion-weighted magnetic resonance imaging (DWI-MRI) performed with apparent diffusion coefficient (ADC) values for the detection of cervical lymphadenopathy.

MATERIALS AND METHODS

Studies evaluating DWI-MRI for the detection of cervical lymphadenopathy were systematically searched for in the MEDLINE, EMBASE, Cancerlit, and Cochrane Library and other database from January 1995 to November 2010. By node-based data analyses, Cochrane methodology was used for the results of this meta-analysis.

RESULTS

Eight studies enrolling a total of 229 individuals were eligible for inclusion. Significant differences were found between malignant nodes and benign nodes of the mean ADC value (WMD [weighted-mean difference]: 1.19, 95% CI: [1.02, 1.35] × 10(-3) mm(2) /s, [P < 0.05]). In the secondary outcomes, significant differences were found between lymphomatous nodes and benign nodes (WMD: 1.33, 95% CI: [0.89, 1.77] × 10(-3) mm(2) /s), and nodes originating from highly or moderately differentiated cancer (WMD: 0.24, 95% CI: [0.21, 0.28] × 10(-3) mm(2) /s, [P < 0.05]), and nodes originating from poorly differentiated cancers (WMD: 0.10, 95% CI: [0.06, 0.14] × 10(-3) mm(2) /s, [P < 0.05]).

CONCLUSION

DWI-MRI performed with ADC values shows significant differences among malignant nodes, lymphomatous nodes, and benign nodes in cervical lymphadenopathy.

Pretreatment diffusion-weighted and dynamic contrast-enhanced MRI for prediction of local treatment response in squamous cell carcinomas of the head and neck

OBJECTIVE

The objective of our study was to predict response to chemoradiation therapy in patients with head and neck squamous cell carcinoma (HNSCC) by combined use of diffusion-weighted imaging (DWI) and high-spatial-resolution, high-temporal-resolution dynamic contrast-enhanced MRI (DCE-MRI) parameters from primary tumors and metastatic nodes.

SUBJECTS AND METHODS

Thirty-two patients underwent pretreatment DWI and DCE-MRI using a modified radial imaging sequence. Postprocessing of data included motion-correction algorithms to reduce motion artifacts. The median apparent diffusion coefficient (ADC), volume transfer constant (K(trans)), extracellular extravascular volume fraction (v(e)), and plasma volume fraction (v(p)) were computed from primary tumors and nodal masses. The quality of the DCE-MRI maps was estimated using a threshold median chi-square value of 0.10 or less. Multivariate logistic regression and receiver operating characteristic curve analyses were used to determine the best model to discriminate responders from nonresponders.

RESULTS

Acceptable χ(2) values were observed from 84% of primary tumors and 100% of nodal masses. Five patients with unsatisfactory DCE-MRI data were excluded and DCE-MRI data for three patients who died of unrelated causes were censored from analysis. The median follow-up for the remaining patients (n = 24) was 23.72 months. When ADC and DCE-MRI parameters (K(trans), v(e), v(p)) from both primary tumors and nodal masses were incorporated into multivariate logistic regression analyses, a considerably higher discriminative accuracy (area under the curve [AUC] = 0.85) with a sensitivity of 81.3% and specificity of 75% was observed in differentiating responders (n = 16) from nonresponders (n = 8).

CONCLUSION

The combined use of DWI and DCE-MRI parameters from both primary tumors and nodal masses may aid in prediction of response to chemoradiation therapy in patients with HNSCC.

Characterization and therapy monitoring of head and neck carcinomas using diffusion-imaging-based intravoxel incoherent motion parameters-preliminary results

INTRODUCTION

Using the intravoxel incoherent motion (IVIM) model, diffusion-related coefficient (D) and perfusion-related parameter (f) can be measured. Here, we used IVIM imaging to characterize squamous cell carcinomas of head and neck (HNSCC) and evaluated its application in follow-up after nonsurgical organ preserving therapy.

METHODS

Twenty-two patients with locally advanced HNSCC (clinical stage III to IVb) were examined before treatment using eight different b values (b = 0, 50, 100, 150, 200, 250, 700, 800 s/mm(2)). All patients were followed for at least 7.5 months after conclusion of therapy. In 16 of these patients, follow-up MRI was available. Using the IVIM approach, f and D were extracted using a bi-exponential fit. For comparison, ADC maps were calculated.

RESULTS

The initial values of f before therapy were located between 5.9 % and 12.9 % (mean: 9.4 ± 2.4 %) except for two outliers (f = 17.9 % and 18.2 %). These two patients exclusively displayed poor initial treatment response. Overall, high initial f (13.1 ± 4.1 % vs. 9.1 ± 2.4 %) and ADC (1.17 ± 0.08 × 10(-3) mm(2)/s vs. 0.98 ± 0.19 × 10(-3) mm(2)/s) were associated with poor short term outcome (n = 6) after 7.5 months follow-up. D values before treatment were 0.98 × 10(-3) ± 0.18 mm(2)/s and ADC values were 1.03 × 10(-3) ± 0.18 mm(2)/s. At follow-up, in all primary responders, D (69 ± 52 %), f (65 ± 46 %), and ADC (68 ± 49%) increased.

CONCLUSIONS

Our preliminary evaluation indicates that an initial high f may predict poor prognosis in HNSCC. In responders, a significant increase of all IVIM parameters after therapy was demonstrated.

Head and neck squamous cell carcinoma: diagnostic performance of diffusion-weighted MR imaging for the prediction of treatment response

PURPOSE

To determine the diagnostic performance of diffusion-weighted (DW) imaging for the prediction of treatment failure in primary head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

The study was approved by the local institutional ethics committee and conducted with informed written consent in patients with primary HNSCC treated with radiation therapy and chemotherapy. DW imaging of the primary tumor was performed before treatment in 37 patients and was repeated within 2 weeks of treatment in 30 patients. Histograms of apparent diffusion coefficients (ADCs) were analyzed, and mean ADC, kurtosis, skewness, and their respective percentage change were correlated for local failure and local control at 2 years by using the Student t test. Univariate and multivariate analyses of the ADC parameters, T stage, and tumor volume were performed by using logistic regression for prediction of local failure.

RESULTS

Local failure occurred in 16 of 37 (43%) patients and local control occurred in 21 of 37 (57%) patients. Pretreatment ADC parameters showed no correlation with local failure. There was significant intratreatment increase in mean ADC and a decrease in skewness and kurtosis (P < .001, P < .001, P = .024, respectively) for the whole group of patients when compared with those before treatment. During treatment, primary tumors showed a significantly lower increase in percentage change of mean ADC, higher skewness, and higher kurtosis for local failure than for local control (P = .016, .015, and .040, respectively). These ADC parameters also were significant for predicting local failure with use of univariate but not multivariate analysis.

CONCLUSION

Early intratreatment DW imaging has the potential to allow prediction of treatment response at the primary site in patients with HNSCC.

FDG PET/CT and diffusion-weighted imaging of head and neck squamous cell carcinoma: comparison of prognostic significance between primary tumor standardized uptake value and apparent diffusion coefficient

PURPOSE

To compare primary tumor (18)F-fluorodeoxyglucose (FDG) maximum standardized uptake value (SUV(max)) and diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) obtained in the same patients with head and neck squamous cell carcinoma (HNSCC) to clarify the prognostic significance of both indexes.

MATERIALS AND METHODS

The study population comprised 26 patients with HNSCC visible on both pretreatment FDG PET/CT and DWI. Correlation between SUV(max) and ADC (b values; 0 and 800 seconds/mm(2)) was analyzed by the Spearman's rank test. Disease-free survival (DFS) was calculated by the Kaplan-Meier method. Prognostic significance was assessed by the long-rank test and Cox proportional hazards analysis.

RESULTS

SUV(max) and ADC correlated significantly and negatively (ρ = -0.566, P = 0.005). High (>12.1) SUV(max) (P < 0.001), low (≤ 0.88) ADC (P = 0.009), high (T3-4) T stage (P = 0.030), and high (N2-3) N stage (P = 0.007) were significant in predicting poor 2-year DFS. The accuracy for predicting disease events was 81% (21/26) for SUV(max) (>12.1) and 73% (19/26) for ADC(≤ 0.88) without significant difference between them (P = 0.52). Disease event hazards ratios for significant unadjusted SUV(max) (P = 0.015) and ADC (P = 0.039) remained significant when adjusted for other dichotomized clinical covariates (SUV(max); P = 0.009-0.039, ADC; P = 0.017-0.037) except SUV(max) for ADC and ADC for SUV(max) and T stage.

CONCLUSION

These results suggest that pretreatment primary tumor SUV(max) and ADC correlate significantly and negatively and both may have similar potential to predict DFS or disease events of HNSCC.

Utility of pretreatment mean apparent diffusion coefficient and apparent diffusion coefficient histograms in prediction of outcome to chemoradiation in head and neck squamous cell carcinoma

PURPOSE

This study aimed to evaluate pretreatment whole-tumor mean apparent diffusion coefficient (ADC) and ADC histogram as predictors of outcome to chemoradiation in patients with head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

Patients with HNSCC underwent pretreatment 3-T diffusion-weighted magnetic resonance imaging with calculation of mean ADC and ADC histograms. Outcomes were determined 2 years after chemoradiation. Positive outcome was defined as no abnormal 18-fluoro deoxy glucose uptake on posttherapy computed tomography-positron emission tomography (or abnormal uptake that was proven benign), no locoregional recurrence or metastatic disease, and no requirement for salvage surgery. Negative outcome was defined as residual abnormal 18-fluoro deoxy glucose avidity that was proven malignant, salvage surgery requirement, locoregional recurrence or metastatic disease, death, or a combination of these. A 2-sample t test was used to compare the mean ADC between patients with positive and negative outcomes. The ADC cut point for dividing the groups was determined by looking at its distribution. A Kaplan-Meier plot was produced, and a log-rank test was conducted with calculation of sensitivity, specificity, and positive and negative predictive values.

RESULTS

Nine patients showed positive and 8 showed negative outcomes. Significant difference (P = 0.03) was seen in mean ADC (in 10 mm/s) between patients showing positive and negative outcomes (1.18 and 1.43, respectively). According to the log-rank test, tumors with greater than 45% of their volume below the ADC threshold of 1.15 × 10 mm/s were more likely to have a positive outcome (accuracy, 77%).

CONCLUSIONS

Patients with HNSCC demonstrating lower pretreatment ADC and with greater than 45% of volume below ADC threshold of 1.15 × 10 mm/s may have better outcome to chemoradiation at 2 years.

Biologic imaging of head and neck cancer: the present and the future

While anatomic imaging (CT and MR imaging) of HNC is focused on diagnosing and/or characterizing the disease, defining its local extent, and evaluating distant spread, accurate assessment of the biologic status of the cancer (cellularity, growth rate, response to nonsurgical chemoradiation therapy, and so forth) can be invaluable for prognostication, planning therapy, and follow-up of lesions after therapy. The combination of anatomic and biologic imaging techniques can thus provide a more comprehensive evaluation of the patient. The purpose of this work was to review the present and future clinical applications of advanced biologic imaging techniques in HNC evaluation and management. As part of the biologic imaging array, we discuss MR spectroscopy, diffusion and perfusion MR imaging, CTP, and FDG-PET scanning and conclude with exciting developments that hold promise in assessment of tumor hypoxia and neoangiogenesis.

Apparent diffusion coefficient calculated with relatively high b-values correlates with local failure of head and neck squamous cell carcinoma treated with radiotherapy

BACKGROUND AND PURPOSE

Few studies have investigated the relationship between ADC and clinical outcome in HNSCC. Our hypothesis has that relatively high pretreatment ADC would correlate with local failure of HNSCC treated with radiation therapy.

MATERIALS AND METHODS

This includes prospective and validation studies. Seventeen patients treated with radiation therapy for primary HNSCC completed the prospective study. Variables considered to affect local failure including MR imaging-related parameters such as ADC and its change ratio were compared between patients with local failure and controls, and those showing difference or association with local failure were further tested by survival analysis. Furthermore, variables were analyzed in 40 patients enrolled in the validation study.

RESULTS

Relatively high ADC calculated with b-values (300, 500, 750, and 1000 s/mm(2)) before treatment, high ADC increase ratio, and treatment method (chemoradiotherapy versus radiation therapy alone) revealed significant difference between patients with local failure and controls or association with local failure. In Cox proportional hazard testing, high ADC before treatment alone showed significant association with local failure (P = .0186). In the validation study, tumor volume before treatment, high ADC before treatment, T stage (T12 versus T34), and treatment method showed significance. Tumor volume before treatment (P = .0217) and high ADC before treatment (P = .0001) revealed significant association with local failure in Cox proportional hazard testing. High ADC before treatment was superior to tumor volume before treatment regarding association with local failure.

CONCLUSIONS

These results suggest pretreatment ADC obtained at high b-values as well as tumor volume correlate with local failure of HNSCC treated with radiation therapy.

Diffusion weighted imaging in predicting progression free survival in patients with squamous cell carcinomas of the head and neck treated with induction chemotherapy

RATIONALE AND OBJECTIVES

The aim of this study was to assess the role of diffusion-weighted imaging in predicting progression-free survival in patients with head and neck squamous cell carcinoma (HNSCC) treated with induction chemotherapy.

MATERIALS AND METHODS

Eighteen patients with HNSCC underwent diffusion-weighted imaging studies prior to treatment and within 3 weeks after completion of induction chemotherapy. Median apparent diffusion coefficient (ADC) values were computed from the largest cervical metastatic lymph node. Percentage changes in ADC values from pretreatment to posttreatment time points were compared between alive and dead patients using the Mann-Whitney U test. P values < .05 were considered statistically significant.

RESULTS

A 22% increase in ADC was observed after induction chemotherapy in alive patients (n = 15), while patients who died from HNSCC (n = 3) demonstrated a 33% decrease in ADC. The difference in percentage change in ADC between alive and dead patients was significant (P = .039).

CONCLUSIONS

ADC may be a useful marker in predicting progression-free survival in patients with HNSCC undergoing induction chemotherapy.

High-resolution diffusion-weighted imaging of neck lymph nodes using 2D-single-shot interleaved multiple inner volume imaging diffusion-weighted echo-planar imaging at 3T

BACKGROUND AND PURPOSE

2D-ss-IMIV-DWEPI is an ss-DWEPI with greatly reduced geometric distortion. The purposes of this paper are to 1) evaluate of the utility of 2D-ss-IMIV-DWEPI for high-resolution neck LN imaging; 2) determine whether 2D-ss-IMIV-DWEPI can depict normal LN hilum; and 3) evaluate whether the inclusion of LN hilum within ROIs affects the measured LN ADC.

MATERIALS AND METHODS

HR-DWI was acquired with 1-mm² in-plane resolution and 2-mm section thickness by using 2D-ss-IMIV-DWEPI. In total, 58 LNs from 18 subjects were evaluated. The ADC map was calculated by using DWI with b = 10 and 300 s/mm². In those LNs where the LN hilum could be recognized, the LN ADC was measured with and without inclusion of the hilum, and the mean difference of the resulting ADC values was determined.

RESULTS

The hilar structure was identified by DWI in 15 LNs. The ADC of the hilum was 1.981 ± 0.331 × 10⁻³ mm²/s. In these 15 LNs, the ADC value excluding hilar structure was significantly lower than the ADC value including hilar structure (0.983 ± 0.169 versus 1.206 ± 0.244 × 10⁻³ mm²/s; P < .0001). The mean ADC in a total of 58 LNs excluding the hilar structure was significantly lower than the value obtained including the hilar structure (1.034 ± 0.183 versus 1.095 ± 0.213 × 10⁻³ mm²/s; P = .0002).

CONCLUSIONS

HR-DWI of neck LNs obtained by using 2D-ss-IMIV-DWEPI could identify the hilar structure. The ADC of normal neck LNs seemed significantly different when the hilum was included. The results suggest that HR-DWI may be helpful to aid selection of proper ROIs within LNs for accurate and reliable ADC measurements.

Applications of molecular imaging

Today molecular imaging technologies play a central role in clinical oncology. The use of imaging techniques in early cancer detection, treatment response, and new therapy development is steadily growing and has already significantly impacted on clinical management of cancer. In this chapter, we overview three different molecular imaging technologies used for the understanding of disease biomarkers, drug development, or monitoring therapeutic outcome. They are (1) optical imaging (bioluminescence and fluorescence imaging), (2) magnetic resonance imaging (MRI), and (3) nuclear imaging (e.g., single-photon emission computed tomography (SPECT) and positron emission tomography (PET)). We review the use of molecular reporters of biological processes (e.g., apoptosis and protein kinase activity) for high-throughput drug screening and new cancer therapies, diffusion MRI as a biomarker for early treatment response and PET and SPECT radioligands in oncology.