Neoplastic Invasion of Laryngeal Cartilage: Reassessment of Criteria for Diagnosis at MR Imaging

CT and MR anatomy of the larynx and hypopharynx

Imaging of the larynx and hypopharynx is frequently requested to assess the extent of neoplasms beyond the field of view of endoscopic evaluation. The combination of optical and cross-sectional imaging allows tumors to be classified according to AJCC/UICC guidelines. A thorough understanding of laryngeal and hypopharyngeal anatomy is crucial to guide the radiological eye along the possible pathways of the spread of diseases and to guide differential diagnoses. Computed tomography (CT) has been the first cross-sectional imaging technique used to evaluate the larynx and hypopharynx; its spatial resolution combined with volumetric capability and the use of injectable contrast medium made CT the working horse in the assessment of neoplastic and inflammatory diseases. In the last two decades, magnetic resonance (MR) supported CT in the most challenging cases, when the optimal contrast resolution due to the multisequence portfolio is needed to assess the neoplastic involvement of laryngeal cartilages, paraglottic space(s), and extra laryngeal spread. The aim of this paper is to give a comprehensive radiological overview of larynx and hypopharynx complex anatomy, combining in vivo images, anatomical sections, and images of ex vivo specimens.

Diagnosis of skull-base invasion by nasopharyngeal tumors on CT with a deep-learning approach

PURPOSE

To develop a convolutional neural network (CNN) model to diagnose skull-base invasion by nasopharyngeal malignancies in CT images and evaluate the model's diagnostic performance.

MATERIALS AND METHODS

We divided 100 malignant nasopharyngeal tumor lesions into a training (n = 70) and a test (n = 30) dataset. Two head/neck radiologists reviewed CT and MRI images and determined the positive/negative skull-base invasion status of each case (training dataset: 29 invasion-positive and 41 invasion-negative; test dataset: 13 invasion-positive and 17 invasion-negative). Preprocessing involved extracting continuous slices of the nasopharynx and clivus. The preprocessed training dataset was used for transfer learning with Residual Neural Networks 50 to create a diagnostic CNN model, which was then tested on the preprocessed test dataset to determine the invasion status and model performance. Original CT images from the test dataset were reviewed by a radiologist with extensive head/neck imaging experience (senior reader: SR) and another less-experienced radiologist (junior reader: JR). Gradient-weighted class activation maps (Grad-CAMs) were created to visualize the explainability of the invasion status classification.

RESULTS

The CNN model's diagnostic accuracy was 0.973, significantly higher than those of the two radiologists (SR: 0.838; JR: 0.595). Receiver operating characteristic curve analysis gave an area under the curve of 0.953 for the CNN model (versus 0.832 and 0.617 for SR and JR; both p < 0.05). The Grad-CAMs suggested that the invasion-negative cases were present predominantly in bone marrow, while the invasion-positive cases exhibited osteosclerosis and nasopharyngeal masses.

CONCLUSIONS

This CNN technique would be useful for CT-based diagnosis of skull-base invasion by nasopharyngeal malignancies.

The impact of margins in laryngeal cancer patients treated with transoral laser microsurgery: a systematic review and meta-analysis

PURPOSE

In laryngeal squamous cell carcinoma (LSCC) treated with transoral laser microsurgery (TOLMS), the status of margins significantly affected local control. When a positive or close margin is present, there is no ubiquitous consensus regarding further treatments. The rationale of the present systematic review and meta-analysis is to investigate the survival impact of the status of the margins in patients affected by LSCC treated with TOLMS.

DATA SOURCES

PubMed, EMBASE, and Cochrane Library.

METHODS

We performed a systematic search, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria were: patients affected by LSCC, staged according to the American Joint Committee on Cancer Staging System and treated by TOLMS without any previous treatment; margins status (close, positive, negative) and the adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) of overall survival, disease-specific survival, and disease-free survival has to be reported.

RESULTS

Nine studies were deemed eligible for the qualitative analysis, and 3 for the quantitative analysis to investigate the association between margin status and OS. The cumulative number of patients was 3130. The sample size ranged from 96 to 747 patients. The follow-up period ranged from 0 to 201 months. The meta-analysis results show that positive margins have an aHR of 1.30 yet with CI range (0.56 to 2.97).

CONCLUSIONS

Our current meta-analysis results are unable to definitively assess the real impact of resection margins on OS. Few authors provide accurate data regarding position and types of margins. Further prospective or high-quality studies are required.

The Diagnostic Value of CEUS in Assessing Non-Ossified Thyroid Cartilage Invasion in Patients with Laryngeal Squamous Cell Carcinoma

Background: Accurate assessment of thyroid cartilage invasion in squamous cell carcinoma (SCC) of the larynx remains a challenge in clinical practice. The aim of this study was to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS), contrast-enhanced computed tomography (CECT), and magnetic resonance imaging (MRI) in the detection of non-ossified thyroid cartilage invasion in patients with SCC. Methods: CEUS, CECT, and MRI scans of 27 male patients with histologically proven SCC were evaluated and compared. A total of 31 cases were assessed via CEUS and CECT. The MR images of five patients and six cases were excluded (one patient had two suspected sites), leaving twenty-five cases for analysis via MRI. Results: CEUS showed the highest accuracy and specificity compared with CECT and MRI (87.1% vs. 64.5% and 76.0% as well as 84.0% vs. 64.0% and 72.7%, respectively). The sensitivity and negative predictive value of CEUS and MRI were the same (100%). CEUS yielded four false-positive findings. However, there were no statistically significant differences among the imaging modalities (p > 0.05). Conclusions: CEUS showed better diagnostic performance than CECT and MRI. Therefore, CEUS has the potential to accurately assess non-ossified thyroid cartilage invasion and guide appropriate treatment decisions, hopefully leading to improved patient outcomes.

Twenty questions from the surgeon to the radiologist to better plan an open partial horizontal laryngectomy

Open partial horizontal laryngectomies (OPHLs) represent a valuable therapeutic option for tumors of the intermediate T-category and, in selected cases, for locally advanced tumors with low-volume extra-laryngeal extension. The eligibility of patients treated with this type of surgery has increased with the introduction of the modular approach to OPHL planning. This strategy follows the introduction of the classification proposed by the European Laryngological Society, based on the extent of horizontal resection. Optimization of the selection is the result of a meticulous work-up process involving close cooperation between experienced surgeons and radiologists, followed by final quality control by pathologists. Computed tomography and magnetic resonance imaging are study methods whose pearls and pitfalls are well known, especially when performed at a high level of expertise. In this paper, based on the experience of two high-volume centers, a checklist of 20 questions addressed by the surgeon to the radiologist before planning an OPHL was proposed. Considerations regarding case selection are reported for each of the questioned parameters. A very simple question-and-answer process is easy to understand and mainly addressed by less experienced colleagues who wish to increase their knowledge and skills in performing this type of surgery.

Changes in serial multiparametric MRI and FDG-PET/CT functional imaging during radiation therapy can predict treatment response in patients with head and neck cancer

OBJECTIVES

To test if tumour changes measured using combination of diffusion-weighted imaging (DWI) MRI and FDG-PET/CT performed serially during radiotherapy (RT) in mucosal head and neck carcinoma can predict treatment response.

METHODS

Fifty-five patients from two prospective imaging biomarker studies were analysed. FDG-PET/CT was performed at baseline, during RT (week 3), and post RT (3 months). DWI was performed at baseline, during RT (weeks 2, 3, 5, 6), and post RT (1 and 3 months). The ADCmean from DWI and FDG-PET parameters SUVmax, SUVmean, metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were measured. Absolute and relative change (%∆) in DWI and PET parameters were correlated to 1-year local recurrence. Patients were categorised into favourable, mixed, and unfavourable imaging response using optimal cut-off (OC) values of DWI and FDG-PET parameters and correlated to local control.

RESULTS

The 1-year local, regional, and distant recurrence rates were 18.2% (10/55), 7.3% (4/55), and 12.7% (7/55), respectively. ∆Week 3 ADCmean (AUC 0.825, p = 0.003; OC ∆ > 24.4%) and ∆MTV (AUC 0.833, p = 0.001; OC ∆ > 50.4%) were the best predictors of local recurrence. Week 3 was the optimal time point for assessing DWI imaging response. Using a combination of ∆ADCmean and ∆MTV improved the strength of correlation to local recurrence (p ≤ 0.001). In patients who underwent both week 3 MRI and FDG-PET/CT, significant differences in local recurrence rates were seen between patients with favourable (0%), mixed (17%), and unfavourable (78%) combined imaging response.

CONCLUSIONS

Changes in mid-treatment DWI and FDG-PET/CT imaging can predict treatment response and could be utilised in the design of future adaptive clinical trials.

CLINICAL RELEVANCE STATEMENT

Our study shows the complementary information provided by two functional imaging modalities for mid-treatment response prediction in patients with head and neck cancer.

KEY POINTS

•FDG-PET/CT and DWI MRI changes in tumour during radiotherapy in head and neck cancer can predict treatment response. •Combination of FDG-PET/CT and DWI parameters improved correlation to clinical outcome. •Week 3 was the optimal time point for DWI MRI imaging response assessment.

The Effectiveness of White Light Endoscopy Combined With Narrow Band Imaging Technique Using Ni Classification in Detecting Early Laryngeal Carcinoma in 114 Patients: Our Clinical Experience

INTRODUCTION

By displaying tumor-specific neoangiogenesis, narrow band imaging (NBI), a novel imaging approach, enhances the diagnosis of head and neck cancers and makes it more accurate OBJECTIVE: To determine the effect of NBI in combination with white light endoscopy (WLE) for diagnosis of preneoplastic or neoplastic laryngeal cancers according to Ni classification and to conclude if higher Ni classification and tumor stage are related.

METHODS

We enrolled 114 patients with various laryngeal cancer between December 2018 and June 2021. Patients were examined with WLE and NBI. Squamous cell carcinoma (SCC) accounted for 46 cases, benign lesions 30 cases, and nondysplastic, low-grade, and severe dysplasias for 38 cases. Based on characteristics of the intraepithelial papillary capillary loop (IPCL), endoscopic NBI results were divided into five categories (I, II, III, IV, and V). Type I-IV are regarded to be benign, while type V is considered to be cancerous. An incisional biopsy was conducted to assess histopathology, and the histopathology was compared to the NBI results. We assessed the negative predictive value (NPV), positive predictive value (PPV), specificity, and sensitivity for WLE alone and WLE combined with NBI. Analyses were conducted using SPSS software version 26.

RESULTS

The WLE combined with NBI showed excellent sensitivity (96%) compared to WLE (86.4%). Specificity was higher in the WLE combined with NBI (96.4%) than WLE alone (91.7%). WLE combined with NBI saw a NPV of 89% as compared with WLE with 88%. WLE and WLE in combination with NBI, recorded a PPV of 90% and 98%, respectively.

CONCLUSION

The accuracy of detecting laryngeal cancer increases when WLE and NBI are combined. Combined NBI with WLE remains highly sensitive to early glottis cancer. Accuracy of preoperative NBI was high. In the diagnosis of laryngeal cancer, a higher Ni classification closely correlates with the late stages of the glottis tumor.

How to prepare for a bright future of radiology in Europe

Because artificial intelligence (AI)-powered algorithms allow automated image analysis in a growing number of diagnostic scenarios, some healthcare stakeholders have raised doubts about the future of the entire radiologic profession. Their view disregards not only the role of radiologists in the diagnostic service chain beyond reporting, but also the many multidisciplinary and patient-related consulting tasks for which radiologists are solicited. The time commitment for these non-reporting tasks is considerable but difficult to quantify and often impossible to fulfil considering the current mismatch between workload and workforce in many countries. Nonetheless, multidisciplinary, and patient-centred consulting activities could move up on radiologists' agendas as soon as AI-based tools can save time in daily routine. Although there are many reasons why AI will assist and not replace radiologists as imaging experts in the future, it is important to position the next generation of European radiologists in view of this expected trend. To ensure radiologists' personal professional recognition and fulfilment in multidisciplinary environments, the focus of training should go beyond diagnostic reporting, concentrating on clinical backgrounds, specific communication skills with referrers and patients, and integration of imaging findings with those of other disciplines. Close collaboration between the European Society of Radiology (ESR) and European national radiologic societies can help to achieve these goals. Although each adequate treatment begins with a correct diagnosis, many health politicians see radiologic procedures mainly as a cost factor. Radiologic research should, therefore, increasingly investigate the imaging impact on treatment and outcome rather than focusing mainly on technical improvements and diagnostic accuracy alone.Critical relevance statement Strategies are presented to prepare for a successful future of the radiologic profession in Europe, if AI-powered tools can alleviate the current reporting overload: engaging in multidisciplinary activities (clinical and integrative diagnostics), enhancing the value and recognition of radiologists' role through clinical expertise, focusing radiological research on the impact on diagnosis and outcome, and promoting patient-centred radiology by enhancing communication skills.Key points • AI-powered tools will not replace radiologists but hold promise to reduce the current reporting burden, enabling them to reinvest liberated time in multidisciplinary clinical and patient-related tasks.• The skills and resources for these tasks should be considered when recruiting and teaching the next generation of radiologists, when organising departments and planning staffing.• Communication skills will play an increasing role in both multidisciplinary activities and patient-centred radiology.• The value and importance of a correct and integrative diagnosis and the cost of an incorrect imaging diagnosis should be emphasised when discussing with non-medical stakeholders in healthcare.• The radiologic community in Europe should start now to prepare for a bright future of the profession for the benefit of patients and medical colleagues alike.

Dual-energy CT for the detection of skull base invasion in nasopharyngeal carcinoma: comparison of simulated single-energy CT and MRI

BACKGROUND

Skull base invasion in nasopharyngeal carcinoma (NPC) was shown to be a poor negative prognostic factor, and dual-energy CT (DECT) has heralded a new approach to detect this condition. The study aims to evaluate the value of DECT for detection of skull base invasion in NPC and compare the diagnostic performance of DECT with those of simulated single-energy CT (SECT) and MRI.

METHODS

The imaging findings of 50 NPC patients and 31 participants in control group which underwent DECT examinations were assessed in this retrospective study. The skull base invasions were evaluated using 5-point scale by two blind observers. ROC analysis, Mcnemar test, paired t test, weighted K statistics and intraclass correlation coefficient were performed to evaluate the diagnostic performance of simulated SECT, MRI and DECT.

RESULTS

Quantitative analysis of DECT parameters showed higher normalized iodine concentration and effective atomic number values in sclerosis and lower values in erosion than those in normal bones (both p < 0.05). Compared with simulated SECT and MRI, the diagnostic sensitivity for DECT was significantly improved from 75% (simulated SECT) and 84.26% (MRI) to 90.74% (DECT) (both p < 0.001), specificity from 93.23% and 93.75% to 95.31 (both p < 0.001), accuracy from 86.67% and 90.33% to 93.67%, and AUC from 0.927 and 0.955 to 0.972 (both p < 0.05), respectively.

CONCLUSIONS

DECT demonstrates better diagnostic performance than simulated SECT and MRI for detecting skull base invasions in NPC, even those slight bone invasions in early stage, with higher sensitivity, specificity and accuracy.

Diagnostic Assessment (Imaging) and Staging of Laryngeal Cancer

Diagnosis of larynx cancer relies on a detailed history and physical and objective assessment with endoscopy and imaging. Endoscopy is needed to assess for vocal fold function that directly affects staging. Computed tomography and MRI can be used to assess for tumor extent in relation to intra- and extra-laryngeal structures, especially paraglottic and pre-epiglottic space involvement as well as cartilage invasion. Accurate staging is critical for subsequent treatment decision-making regarding larynx preservation.

The clinical value of DCE-MRI for differentiating secondary laryngeal cartilage lesions

To explore the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the assessment of laryngeal cartilage lesions. In this study, 3 groups of cases were selected, including 16 cases benign lesions of the laryngopharynx as the benign group, 17 cases malignant lesions of laryngopharynx as the malignant group and 23 healthy adults as the control group. Conventional magnetic resonance imaging and DCE-MRI were performed with a 3.0 T MR scanner. cutoff, sensitivity, specificity and area under the curve values were calculated via receiver operating characteristic curve analysis based on the pathologic findings of surgically resected specimens. There were significant differences in the values of the volume transfer constant (Ktrans), the rate constant between the extravascular extracellular space and blood plasma (Kep) and The extravascular extracellular space fractional volume (Ve) between the control, benign and malignant groups (P < .005). Among the 3 groups, the malignant group had the highest Ktrans and Ve values (0.8681 ± 0.3034 and 0.6186 ± 0.2405, respectively), and the benign group had the highest Kep value (2.445 ± 0.7346). The cutoff points of the Ktrans, Kep, and Ve values of the control, benign and malignant groups were 0.39, 1.261, and 0.195; 0.471, 0.964, and 0.235; and 0.706, 2.005, and 0.659, respectively. The Ktrans, Kep, and Ve values obtained via DCE-MRI may enable differentiating laryngeal cartilage lesions. DCE-MRI can be used to evaluate laryngeal cartilage lesions accurately and quantitatively.

Delineation uncertainties of tumour volumes on MRI of head and neck cancer patients

•

Role of target delineation uncertainties in head and neck cancer patients.

•

Knowing contouring variations for MRI allows better adaptation of MRLinac for H&N cancers.

•

An interobserver variation for GTV among 8 observers was below 2 mm using MRI.

•

Variability between observers might improve using other imaging modalities.

Background

During the last decade, radiotherapy using MR Linac has gone from research to clinical implementation for different cancer locations. For head and neck cancer (HNC), target delineation based only on MR images is not yet standard, and the utilisation of MRI instead of PET/CT in radiotherapy planning is not well established. We aimed to analyse the inter-observer variation (IOV) in delineating GTV (gross tumour volume) on MR images only for patients with HNC.

Material/methods

32 HNC patients from two independent departments were included. Four clinical oncologists from Denmark and four radiation oncologists from Australia had independently contoured primary tumour GTVs (GTV-T) and nodal GTVs (GTV-N) on T2-weighted MR images obtained at the time of treatment planning. Observers were provided with sets of images, delineation guidelines and patient synopsis. Simultaneous truth and performance level estimation (STAPLE) reference volumes were generated for each structure using all observer contours. The IOV was assessed using the DICE Similarity Coefficient (DSC) and mean absolute surface distance (MASD).

Results

32 GTV-Ts and 68 GTV-Ns were contoured per observer. The median MASD for GTV-Ts and GTV-Ns across all patients was 0.17 cm (range 0.08–0.39 cm) and 0.07 cm (range 0.04–0.33 cm), respectively. Median DSC relative to a STAPLE volume for GTV-Ts and GTV-Ns across all patients were 0.73 and 0.76, respectively. A significant correlation was seen between median DSCs and median volumes of GTV-Ts (Spearman correlation coefficient 0.76, p < 0.001) and of GTV-Ns (Spearman correlation coefficient 0.55, p < 0.001).

Conclusion

Contouring GTVs in patients with HNC on MRI showed that the median IOV for GTV-T and GTV-N was below 2 mm, based on observes from two separate radiation departments. However, there are still specific regions in tumours that are difficult to resolve as either malignant tissue or oedema that potentially could be improved by further training in MR-only delineation.

Target Definition in MR-Guided Adaptive Radiotherapy for Head and Neck Cancer

Simple Summary

Adaptive radiotherapy for head and neck cancer has become more routine due to an increase in imaging quality and improvement in radiation techniques. With the availability of faster adaptive workflows, it is possible to adapt more easily to (daily) changes. MRI offers besides great anatomical imaging, also functional information about the tumor and surrounding tissue. The aim of this review is to provide current state of evidence about target definition on MRI for adaptive strategies in the treatment of head and neck cancer.

Abstract

In recent years, MRI-guided radiotherapy (MRgRT) has taken an increasingly important position in image-guided radiotherapy (IGRT). Magnetic resonance imaging (MRI) offers superior soft tissue contrast in anatomical imaging compared to computed tomography (CT), but also provides functional and dynamic information with selected sequences. Due to these benefits, in current clinical practice, MRI is already used for target delineation and response assessment in patients with head and neck squamous cell carcinoma (HNSCC). Because of the close proximity of target areas and radiosensitive organs at risk (OARs) during HNSCC treatment, MRgRT could provide a more accurate treatment in which OARs receive less radiation dose. With the introduction of several new radiotherapy techniques (i.e., adaptive MRgRT, proton therapy, adaptive cone beam computed tomography (CBCT) RT, (daily) adaptive radiotherapy ensures radiation dose is accurately delivered to the target areas. With the integration of a daily adaptive workflow, interfraction changes have become visible, which allows regular and fast adaptation of target areas. In proton therapy, adaptation is even more important in order to obtain high quality dosimetry, due to its susceptibility for density differences in relation to the range uncertainty of the protons. The question is which adaptations during radiotherapy treatment are oncology safe and at the same time provide better sparing of OARs. For an optimal use of all these new tools there is an urgent need for an update of the target definitions in case of adaptive treatment for HNSCC. This review will provide current state of evidence regarding adaptive target definition using MR during radiotherapy for HNSCC. Additionally, future perspectives for adaptive MR-guided radiotherapy will be discussed.

Multi parametric magnetic resonance imaging for radiation treatment planning

In recent years, multi-parametric magnetic resonance imaging (MpMRI) has played a major role in radiation therapy treatment planning. The superior soft tissue contrast, functional or physiological imaging capabilities and the flexibility of site-specific image sequence development has placed MpMRI at the forefront. In this article, the present status of MpMRI for external beam radiation therapy planning is reviewed. Common MpMRI sequences, preprocessing and QA strategies are briefly discussed, and various image registration techniques and strategies are addressed. Image segmentation methods including automatic segmentation and deep learning techniques for organs at risk and target delineation are reviewed. Due to the advancement in MRI guided online adaptive radiotherapy, treatment planning considerations addressing MRI only planning are also discussed. This article is protected by copyright. All rights reserved.

MR Imaging of Laryngeal and Hypopharyngeal Cancer

State-of-the-art MR imaging of the larynx and hypopharynx with high-resolution surface coils, parallel imaging techniques, and DWI has several advantages over CT for assessing submucosal tumor spread, in particular neoplastic involvement of the paraglottic space, laryngeal cartilages, and extralaryngeal soft tissues. Current diagnostic MR imaging criteria based on a combination of distinct imaging features on morphologic sequences combined with DWI allow improved discrimination between tumor, peritumoral inflammation, and fibrosis and, ultimately, an increased precision for submucosal tumor delineation, which is a key prerequisite for tailored treatment options. Multiparametric MR imaging with DWI has a higher diagnostic performance than CT.

Preoperative MRI Evaluation of Thyroid Cartilage Invasion in Patients with Laryngohypopharyngeal Cancer: Comparison of Contrast-Enhanced 2D Spin-Echo and 3D T1-Weighted Radial Gradient Recalled-Echo Techniques

BACKGROUND AND PURPOSE

Accurate assessment of thyroid cartilage invasion on preoperative imaging influences management in patients with laryngeal and hypopharyngeal cancers. We evaluated the clinical usefulness of contrast-enhanced 3D T1-weighted radial gradient recalled-echo for preoperative assessment of thyroid cartilage invasion in patients with laryngohypopharyngeal squamous cell carcinoma, compared with 2D spin-echo T1WI.

MATERIALS AND METHODS

Preoperative MR images of 52 consecutive patients who were diagnosed with laryngeal or hypopharyngeal cancer and underwent partial or total laryngectomy were analyzed. Pathologic specimens served as reference standards. Two independent head and neck radiologists evaluated the presence of thyroid cartilage invasion in both contrast-enhanced 2D spin-echo T1WI and 3D gradient recalled-echo sequences. The sensitivity, specificity, and accuracy of the 2 modalities were compared. The area under the curve was a measure of diagnostic performance.

RESULTS

Pathologic neoplastic thyroid cartilage invasion was identified in 24 (46.2%) of the 52 patients. The sensitivity (75.0%), specificity (96.4%), and accuracy (86.5%) of contrast-enhanced 3D gradient recalled-echo were significantly higher than those of 2D spin-echo T1WI (58.3%, 89.3%, and 75.0%; P = .017, .003, and .002, respectively). 3D gradient recalled-echo had significantly better diagnostic performance (area under the curve = 0.963) than 2D spin-echo T1WI (area under the curve = 0.862; P = .010).

CONCLUSIONS

Contrast-enhanced 3D gradient recalled-echo was diagnostically superior in identifying neoplastic thyroid cartilage invasion compared with 2D spin-echo T1WI in patients with laryngohypopharyngeal cancer, and therefore, may provide more accurate preoperative staging.

High-Resolution Laryngeal US: Imaging Technique, Normal Anatomy, and Spectrum of Disease

Although US is one of the most used modalities for head and neck imaging, its use in the diagnosis of laryngeal abnormalities is much less widespread. The standard assessment of laryngeal abnormalities currently involves direct laryngoscopy and cross-sectional imaging (either CT or MRI) but rarely US. US is readily available, noninvasive, and radiation free, and it allows real-time imaging (with video for dynamic assessment), higher resolution than that of cross-sectional imaging, and the performance of targeted fine needle aspiration cytology or biopsy. This modality, particularly with the advent of high-resolution US, has been found to be at least comparable to CT or MRI for diagnosis of malignant lesions and benign abnormalities such as vocal nodules, polyps, cysts, and Reinke edema. Furthermore, it has been found to be more sensitive for diagnosis of abnormalities such as small glottic tumors, and its dynamic capability can be used to identify functional abnormalities such as vocal cord palsy. The authors outline the technique of laryngeal US, which includes strategies to avoid calcified laryngeal cartilage by imaging through the thyrohyoid and cricothyroid membranes with a five-sweep strategy supplemented by cine film of the technique. They also provide US images of common laryngeal abnormalities such as tumors with and without extralaryngeal extension; vallecular, thyroglossal, and vocal cord cysts; laryngeal mucoceles; and vocal cord palsy. Online supplemental material is available for this article. ^©RSNA, 2020.

Impact of magnetic resonance on the decision of conservative surgery in advanced larynx cancer

OBJECTIVE

To evaluate the utility of magnetic resonance images (MRI) in the selection of treatment procedures for intermediate-advanced laryngeal cancers.

MATERIAL AND METHOD

This study included patients with histologically proven laryngeal squamous cell carcinoma defined as cT3 and T4a at our tertiary academic care hospital. All scans were evaluated by two radiologists experienced in head and neck cross-sectional studies. Signal patterns in MRI sections of laryngeal compartment subsites were delineated as T1w, T2w hyperintensity, and T2w intermediate signals, and were compared with the postoperative pathological results. Sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were calculated.

RESULTS

The study included 51 patients with a mean age of 62.55 ± 9.14 (range, 45-80) years. Tumor was glottic in 12 (23.5%) patients, supraglottic in 19 (31.4%) patients, glottic-supraglottic in 11 (21.6%) patients, transglottic in 9 (27%) patients. The posterior paraglottic space had the strongest specificity of MRI according to tumor infiltration in the histologic analysis (specificity 96.9% and sensitivity 78.6%). The specificity of MRI was poor for tumor infiltration in thyroid cartilage (specificity 70.0%). Spearman's test demonstrated that there was a statistically significant correlation between the MRI-based prediction scores of all subunites and the findings of histopathologic analyses (mean±SD: 4.96±4.46-5.53±4.38, respectively, R²: 0.711, p<0.001).

CONCLUSION

The high specificity values of the predictions, which were MRI-based in all subsites, indicated that MRI could provide an important contribution for defining tumor infiltration and the presurgical assessment of patients with tumors of the larynx.

[Current diagnostic imaging and treatment planning for laryngeal cancer]

CLINICAL/METHODICAL ISSUE

Laryngeal cancer is the third most common malignancy in the head and neck region. Endoscopic laryngoscopy with assessment of vocal fold function, microlaryngoscopy with biopsy and computed tomography (CT)/magnetic resonance imaging (MRI) remain the cornerstones of diagnostic workup. Thus, in the context of therapy planning, consideration of individual functional and socioeconomic aspects is of major importance.

STANDARD RADIOLOGICAL METHODS

Due to the short acquisition time and the possibility to perform functional maneuvers, CT is the tool of choice. MRI allows better soft tissue differentiation, but is more susceptible to movement artifacts and is complicated by disease-specific symptoms. The choice of examination method therefore depends on the patient's physical resilience.

PERFORMANCE

Depending on the study, the information on the sensitivity of CT with regard to the question of cartilage infiltration varies between 62 and 87% with a specificity between 75 and 98%. For MRI, sensitivity between 64 and 95% and specificity between 56 and 88% are stated.

ACHIEVEMENTS

The synthesis of the findings from endoscopy, biopsy and imaging is prerequisite for initiation of stage-appropriate treatment. For image interpretation, knowledge of the anatomical landmarks is essential. However, the assessment of posttherapeutic changes also poses a challenge for the radiologist.

PRACTICAL RECOMMENDATIONS

Regular interdisciplinary dialogue between radiologists, otorhinolaryngologists and radiotherapists in the context of primary diagnostics, therapy planning and aftercare is essential.

CT-based radiomics features in the prediction of thyroid cartilage invasion from laryngeal and hypopharyngeal squamous cell carcinoma

Background

Laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC) with thyroid cartilage invasion are considered T4 and need total laryngectomy. However, the accuracy of preoperative diagnosis of thyroid cartilage invasion remains lower. Therefore, the purpose of this study was to assess the potential of computed tomography (CT)-based radiomics features in the prediction of thyroid cartilage invasion from LHSCC.

Methods

A total of 265 patients with pathologically proven LHSCC were enrolled in this retrospective study (86 with thyroid cartilage invasion and 179 without invasion). Two head and neck radiologists evaluated the thyroid cartilage invasion on CT images. Radiomics features were extracted from venous phase contrast-enhanced CT images. The least absolute shrinkage and selection operator (LASSO) and logistic regression (LR) method were used for dimension reduction and model construction. In addition, the support vector machine-based synthetic minority oversampling (SVMSMOTE) algorithm was adopted to balance the dataset and a new LR-SVMSMOTE model was constructed. The performance of the radiologist and the two models were evaluated with receiver operating characteristic (ROC) curves and compared using the DeLong test.

Results

The areas under the ROC curves (AUCs) in the prediction of thyroid cartilage invasion from LHSCC for the LR-SVMSMOTE model, LR model, and radiologist were 0.905 [95% confidence interval (CI): 0.863 to 0.937)], 0.876 (95%CI: 0.830 to 0.913), and 0.721 (95%CI: 0.663–0.774), respectively. The AUCs of both models were higher than that of the radiologist assessment (all P < 0.001). There was no significant difference in predictive performance between the LR-SVMSMOTE and LR models (P = 0.05).

Conclusions

Models based on CT radiomic features can improve the accuracy of predicting thyroid cartilage invasion from LHSCC and provide a new potentially noninvasive method for preoperative prediction of thyroid cartilage invasion from LHSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-020-00359-2.

Genotype of Null Polymorphisms in Genes GSTM1, GSTT1, CYP1A1, and CYP1A1*2A (rs4646903 T>C)/CYP1A1*2C (rs1048943 A>G) in Patients with Larynx Cancer in Southeast Spain

Simple Summary

Epidemiological studies have shown that individual susceptibility to cancer is mediated by genetic and environmental factors. The aim of the present study is to evaluate the individuals’ metabolic genetic susceptibility to toxic habits (smoking and alcohol consumption) by detecting polymorphisms CYP1A1 rs1048943 T>C and CYPA1A2 rs4646903 A>G, and null polymorphisms in GSTM1 and GSTT1 genotypes, comparing a group of healthy control subjects with a population of larynx cancer patients from southeastern Spain. As results patients with larynx cancer present more gene GSTM1 and GSTT1 null polymorphisms, and CYP1A1 rs4646903 T>C polymorphisms.

Abstract

Background: some types of cancer have been associated with the presence of single nucleotide polymorphisms (SNPs) of some genes that encode enzymes: glutathione-S transferase (GST), whose alteration leads to loss of function and a lower capacity to eliminate toxic GSTM1 and GSTT1 null genotypes; SNPs causing loss of function of CYP1A1 or CYP1A1–2 cytochrome P450 enzymes related with a lower capacity to deactivate hydrocarbons related to smoking, which involves a higher risk of developing some smoking-dependent cancers including larynx cancer. Objective: to compare the presence of null SNPs in genes GSTM1, GSTT1, and CYP1A1 rs 4646903 T>C, and CYP1A1–2 RS1048943 A>G in patients with hypopharyngeal and larynx cancer with a healthy control group. Materials and method: The study included a total of 80 patients with hypopharyngeal and laryngeal cancer and 23 healthy subjects. Genomic DNA was obtained from saliva samples, determining genotype GSTM1 (present +, or null −), GSTT1 (present + or null −). Polymorphisms (SNP) in CYP1A1 T>C (present + CC, or absent − TC/TT), and CYP1A1–2 A>G (present + GG, or absent − AG/AA). Results: the mean age of patients with larynx cancer was 62 years and of control subjects 63 years. Of the total sample, over 95% were men, and over 90% were smokers. The presence of null genotypes for GTM1 was 50% in patients with larynx cancer (p = 0.042), while GSTT1 was 88.75% (p = 0.002). CYP1A1 rs4646903 T>C polymorphisms were detected in 100% of cases of larynx cancer and 17.39% of healthy subjects (p > 0.001). Conclusions: patients with larynx cancer present more gene GSTM1 and GSTT1 null polymorphisms, and CYP1A1 rs4646903 T>C polymorphisms.

Laryngeal Compartmentalization Does Not Affect the Prognosis of T3-T4 Laryngeal Cancer Treated by Upfront Total Laryngectomy

A picture is emerging in which advanced laryngeal cancers (LCs) are potentially not homogeneous and may be characterized by subpopulations which, if identified, could allow selection of patients amenable to organ preservation treatments in contrast to those to be treated with total laryngectomy (TL). This work aims to analyze a multicentric cohort of T3-T4a LCs treated by upfront TL, investigating the clinical and pathological features that can best predict oncologic outcomes. A total of 149 previously untreated patients who underwent TL for T3-T4a LC at four institutions were analyzed. Survival and disease-control were considered as the main outcomes. A secondary end-point was the identification of covariates associated with nodal status, investigating also the tumor thickness. T and N categories were significantly associated with both overall and disease-specific survival. The number of positive nodes and tracheal involvement were associated with loco-regional failure; post-cricoid area invasion and extra-nodal extension with distant failure. Posterior laryngeal compartment involvement was not a significant prognostic feature, by either univariable and multivariable analyses. These results support the conclusion that laryngeal compartmentalization has no impact on survival in patients treated by upfront TL and the current TNM staging system remains a robust prognosticator in advanced LC.

Imaging of Head and Neck Cancer With CT, MRI, and US

Imaging of head and neck (HN) cancer is a challenge for many radiologists and largely due to the challenging anatomy in a small volume of the body. Additionally, multiple pathologies and the absence of an agreed-upon standard imaging protocol for staging and surveillance add complexity in choosing the most appropriate imaging study. Computed tomography (CT) is often the first-line imaging tool used as it is readily available, relatively cheaper than magnetic resonance (MR) and is rapidly acquired. In comparison, MR is hampered not just by its greater expense and time involved with an imaging study, but the optimization of MR techniques is difficult in this complex part of the body. Over the last decade, additional advanced techniques have been developed for both CT and MR such as dual-energy CT, and perfusion imaging with CT or MR, which may aid in making a more accurate diagnosis and predication of tumor behavior. Ultrasound (US) plays an important role in HN imaging, particularly in the pediatric age group for new neck masses, and in adult patients with known or suspected thyroid pathology. US is also useful for the evaluation of other superficial masses in the neck and for guiding fine needle aspiration. This article will focus on each imaging modality, reviewing the benefits and drawbacks of CT, MR, and US as well as additional or advanced techniques within each. It will highlight disease processes where a specific modality is strongly favored as the most appropriate imaging study, and specific HN tumor behaviors that require dedicated imaging protocols or techniques. This review will also discuss the entity of carcinoma of unknown primary, which is often imaged with PET/CT, but for which specific guidelines were introduced in the 8th edition of the American Joint Committee of Cancer/Union for International Cancer Control Staging Manuals.

Current role of computed tomography imaging in the evaluation of cartilage invasion by laryngeal carcinoma

OBJECTIVES

To evaluate thyroid, arytenoid, and cricoid cartilage invasion on computed tomography (CT) imaging in patients undergoing total laryngectomy for both primary and recurrent laryngeal carcinoma. Secondary endpoint was to compare laryngeal cartilage invasion between primary and recurrent tumours.

METHODS

Pre-treatment CT of 40 patients who had undergone total laryngectomy was retrospectively evaluated and compared with histology. Focal erosions of thyroid cartilage were accounted for neoplastic invasion of the inner cortex. Full-thickness thyroid cartilage invasion was defined as a tumour-like tissue replacing thyroid cartilage or extended in extra-laryngeal soft tissues. Sclerosis and erosion of arytenoid and cricoid cartilages were assessed as signs of neoplastic invasion.

RESULTS

CT erosion showed perfect agreement for thyroid inner cortex and cricoid cartilage invasion and almost perfect agreement (87%) for arytenoid cartilage invasion. For tumours in contact with thyroid cartilages, the absence of CT erosion underestimated inner cortex infiltration. CT showed perfect agreement in predicting full-thickness thyroid cartilage invasion only in the case of extra-laryngeal neoplastic extension. Arytenoid sclerosis showed poor correlation with neoplastic invasion. For primary tumours, CT demonstrated good (inner cortex 75%; full-thickness 85%), substantial (67.5%), and perfect (100%) accuracy in thyroid, arytenoid, and cricoid cartilage invasion, respectively. No CT differences were observed between primary and recurrent laryngeal tumours.

CONCLUSION

Tumour-like tissue extension in the extra-laryngeal soft tissues was accurate in predicting thyroid cartilage full-thickness invasion. Erosions of arytenoid, cricoid, and thyroid cartilages' inner cortex on CT were highly indicative of neoplastic infiltration. No CT difference in cartilage infiltration between primary and recurrent tumours was observed.

Comparison of diagnostic performance between CT and MRI for detection of cartilage invasion for primary tumor staging in patients with laryngo-hypopharyngeal cancer: a systematic review and meta-analysis

OBJECTIVE

To compare the diagnostic performance of contrast-enhanced CT with that of MRI in the detection of cartilage invasion in patients with laryngo-hypopharyngeal cancer.

METHODS

A systematic literature search in the Ovid-MEDLINE and EMBASE databases was performed for studies reporting diagnostic accuracy of CT and/or MRI in detecting cartilage invasion from laryngo-hypopharyngeal cancer between 2000 and 2018. The pooled sensitivity and specificity, and their 95% confidence intervals were calculated for CT and MRI using bivariate random effects modeling. Subgroup and meta-regression analyses were performed. Indirect comparison was also performed by univariable meta-regression.

RESULT

Fourteen articles including 776 patients were included in the systematic review and meta-analysis: eight for CT, and six for MRI. CT and MRI showed pooled sensitivities of 66% (95% CI, 49-80%) and 88% (95% CI, 79-93%), and pooled specificities of 90% (95% CI, 82-94%) and 81% (95% CI, 76-84%), respectively. MRI showed significantly higher sensitivity than CT (p = 0.02). The specificities showed no statistically significant difference between CT and MRI (p = 0.39). The CT studies showed heterogeneity and a threshold effect, while MRI showed neither heterogeneity nor threshold effect. In the meta-regression analysis for CT, the type of cartilage analyzed (thyroid only vs. thyroid/cricoid/arytenoid, p < 0.001) was a significant factor influencing the heterogeneity in the diagnostic performance of the CT studies.

CONCLUSIONS

In conclusion, MRI has significantly higher sensitivity than CT for detecting cartilage invasion in patients with laryngo-hypopharyngeal cancer, without a significant difference in the specificity.

KEY POINTS

• MRI has significantly higher sensitivity than CT for detecting cartilage invasion in patients with laryngo-hypopharyngeal cancer.

A Review of Controversial Issues in the Management of Head and Neck Cancer: A Swiss Multidisciplinary and Multi-Institutional Patterns of Care Study-Part 1 (Head and Neck Surgery)

Background: The Head and Neck Cancer Working Group of Swiss Group for Clinical Cancer Research (SAKK) has investigated the level of consensus (LOC) and discrepancy in everyday practice of diagnosis and treatment in head and neck cancer. Materials and Methods: An online survey was iteratively generated with 10 Swiss university and teaching hospitals. LOC below 50% was defined as no agreement, while higher LOC were arbitrarily categorized as low (51-74%), moderate (75-84%), and high (≥85%). Results: Any LOC was achieved in 62% of topics (n = 60). High, moderate and low LOC were found in 18, 20, and 23%, respectively. Regarding Head and Neck Surgery, Radiation Oncology, Medical Oncology, and biomarkers, LOC was achieved in 50, 57, 83, and 43%, respectively. Conclusions: Consensus on clinical topics is rather low for surgeons and radiation oncologists. The questions discussed might highlight discrepancies, stimulate standardization of practice, and prioritize topics for future clinical research.

18F-FDG-PET/CT Imaging in Advanced Glottic Cancer: A Tool for Clinical Decision in Comparison with Conventional Imaging

This study assessed the role of ¹⁸F-FDG PET-CT (PET/CT) to detect the cartilage and paraglottic infiltration in advanced glottic cancer comparing the results with those of conventional imaging (CI) (contrast-enhanced computed tomography and/or magnetic resonance). In addition, we assessed the prognostic value of quantitative parameters, measured on baseline PET/CT, in terms of event-free survival (EFS) and overall survival (OS). We retrospectively analyzed 27 patients with glottic squamous cell carcinoma stage III and IVA, treated in our institute between 2010 and 2016, comparing PET/CT, performed for staging and radiotherapy planning, and CI findings. Cohen's K was used to compare concordance between PET/CT and CI. Imaging findings were correlated with endoscopic evaluation and histological reports (gold standard (GS)). All lesions shown by CI were also detected by PET/CT imaging, and in 5 cases, a better definition of local infiltration was achieved with PET/CT than CI (5 CT). Sensitivity, specificity, and accuracy of PET/CT and CT were 95%, 86%, and 93% and 70%, 86%, and 74% for, respectively. MRI showed sensitivity and specificity of 100%. One false-negative (FN) cases and 1 false-positive (FP) case were observed with PET/CT with no difference compared to MRI (10 cases). Six FN cases and 1 FP case were observed with CT. Cohen's K was 0.60 (PET vs. CI) and 0.80 (PET vs. GS). Patients were followed-up for at least 24 months to calculate EFS and OS. 13 local recurrence and 7 deaths were recorded. Among quantitative PET parameters, baseline MTV was the most powerful predictor of outcome. Our data suggest a reliable sensitivity and accuracy of PET/CT in the evaluation of local extension, proving a useful method for initial local staging in addition to the well-established role in lymph-node and distant sites assessment. Furthermore, pretreatment MTV provides better prognostic information than other PET/CT parameters.

PET/MRI vs PET/CT in Head and Neck Imaging: When, Why, and How?

The increasing availability of hybrid PET/MRI systems has led to a breadth of new publications and opportunities for use of PET/MRI. While PET/CT has been a valuable tool for oncologic staging, including head and neck malignancy, there are several theoretical and practical advantages a PET/MRI system would have over PET/CT in head and neck imaging. This review article discusses the established role of PET/CT, early evidence for the role of PET/MRI, and protocol considerations for both PET/CT and PET/MRI as they apply to head and neck imaging.

Prediction of Posterior Paraglottic Space and Cricoarytenoid Unit Involvement in Endoscopically T3 Glottic Cancer with Arytenoid Fixation by Magnetic Resonance with Surface Coils

Discrimination of the etiology of arytenoid fixation in cT3 laryngeal squamous cell carcinoma (SCC) is crucial for treatment planning. The aim of this retrospective study was to differentiate among possible causes of arytenoid fixation (edema, inflammation, mass effect, or tumor invasion) by analyzing related signal patterns of magnetic resonance (MR) in the posterior laryngeal compartment (PLC) and crico-arytenoid unit (CAU). Seventeen patients affected by cT3 glottic SCC with arytenoid fixation were preoperatively studied by state-of-the-art MR with surface coils. Different signal patterns were assessed in PLC subsites. Three MR signal patterns were identified: A, normal; B, T2 hyperintensity and absence of restriction on diffusion-weighted imaging (DWI); and C, intermediate T2 signal and restriction on DWI. Signal patterns were correlated with the presence or absence of CAU and PLC neoplastic invasion. Patients were submitted to open partial horizontal or total laryngectomy and surgical specimens were analyzed. Pattern A and B did not correlate with neoplastic invasion, while Pattern C strongly did (Spearman’s coefficient = 0.779, p < 0.0001; sensitivity: 100%; specificity: 78%). In conclusion, MR with surface coils is able to assess PLC/CAU involvement with satisfactory accuracy. In absence of Pattern C, arytenoid fixation is likely related to mass effect and/or inflammatory reaction and is not associated with neoplastic invasion.

Role of pretreatment fluorodeoxyglucose positron emission tomography quantitative parameters in prognostication of head-and-neck squamous cell carcinoma

In spite of the good organ preservation strategies available for locally advanced head-and-neck squamous cell carcinoma (HNSCC), failure rates have been reported to be as high as 35%–50%. There has been an increasing interest in predicting response to treatment, to aid early intervention and better outcomes. Fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) is a standard modality for posttreatment evaluation; however, it is still underutilized as a pretreatment investigative modality. Several articles have described quantitative parameters in pretreatment FDG-PET to prognosticate patients and determine the likelihood of response to treatment; however, they are still not used commonly. This article was a review of the literature available on pretreatment FDG-PET quantitative parameters and their value in predicting failure. A thorough review of literature from MEDLINE and EMBASE was performed on pretreatment quantitative parameters in HNSCC. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were reliable parameters to predict response to organ preservation therapy, disease-free survival, and overall survival. Maximum SUV (SUVmax) was an inconsistent parameter. MTV and TLG may help predict poor response to organ preservation to initiate early surgical salvage or modify therapeutic decisions to optimize clinical outcomes. Routine use may provide additional information over SUVmax alone.

Bone Subtraction Iodine Imaging Using Area Detector CT for Evaluation of Skull Base Invasion by Nasopharyngeal Carcinoma

BACKGROUND AND PURPOSE

Conventional CT has generally lower detectability of bone marrow invasion than MR imaging due to lower tissue contrast. The purpose of this study was to compare the diagnostic performance of conventional CT alone or in combination with bone subtraction iodine imaging using area detector CT for the evaluation of skull base invasion in patients with nasopharyngeal carcinoma.

MATERIALS AND METHODS

Forty-four consecutive patients who underwent contrast-enhanced CT using 320-row area detector CT and contrast-enhanced MR imaging for nasopharyngeal carcinoma staging between April 2012 and November 2017 were enrolled in this retrospective study. Bone subtraction iodine images were generated by subtracting pre- and postcontrast volume scans using a high-resolution deformable registration algorithm. Two blinded observers evaluated skull base invasion at multiple sites (sphenoid body, clivus, bilateral base of the pterygoid process, and petrous bone) using conventional CT images alone or in combination with bone subtraction iodine images. Examination of MR and CT images by an experienced neuroradiologist was the reference standard for evaluating sensitivity, specificity, and area under the receiver operating characteristic curve.

RESULTS

Twenty-six patients (59%) showed skull base invasion at 84 sites on the reference standard. Conventional CT plus bone subtraction iodine images showed higher sensitivity (92.9% versus 78.6%, P = .02) and specificity (95.6% versus 86.1%, P = .01) than conventional CT images alone for evaluating skull base invasion. The area under the receiver operating characteristic curve for conventional CT plus bone subtraction iodine (0.98) was significantly larger (P < .001) than the area under the receiver operating characteristic curve for conventional CT alone (0.90).

CONCLUSIONS

Conventional CT plus bone subtraction iodine performs more closely to the accuracy of combining CT and MR imaging compared with conventional CT alone.

Sclerosis of the arytenoid cartilage and glottic carcinoma: A clinical-pathological study

BACKGROUND

Given the relevance of any tumor invasion of the arytenoid cartilage or crico-arytenoid unit to the planning open partial horizontal laryngectomy (OPHL) for laryngeal squamous cell carcinoma (LSCC), it is important to have a reliable radiological test to assess impairments of these structures.

METHODS

We retrospectively compared the endoscopic, radiological, and pathological findings in patients with glottic LSCC who underwent OPHL.

RESULTS

The endoscopic finding of a reduced (impaired or absent) vocal cord motility proved more sensitive, with better positive and negative predictive values, but less specific than the radiological finding of complete arytenoid sclerosis in detecting histologically assessable infiltration of the arytenoid cartilage.

CONCLUSIONS

Endoscopy retains a key role in the preoperative workup for glottic LSCC. CT evidence of complete sclerosis of the arytenoid cartilage is related to a dangerous contiguity of the tumor to the cartilage.

Emerging role of MRI in radiation therapy

Advances in multimodality imaging, providing accurate information of the irradiated target volume and the adjacent critical structures or organs at risk (OAR), has made significant improvements in delivery of the external beam radiation dose. Radiation therapy conventionally has used computed tomography (CT) imaging for treatment planning and dose delivery. However, magnetic resonance imaging (MRI) provides unique advantages: added contrast information that can improve segmentation of the areas of interest, motion information that can help to better target and deliver radiation therapy, and posttreatment outcome analysis to better understand the biologic effect of radiation. To take advantage of these and other potential advantages of MRI in radiation therapy, radiologists and MRI physicists will need to understand the current radiation therapy workflow and speak the same language as our radiation therapy colleagues. This review article highlights the emerging role of MRI in radiation dose planning and delivery, but more so for MR-only treatment planning and delivery. Some of the areas of interest and challenges in implementing MRI in radiation therapy workflow are also briefly discussed. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;48:1468-1478.

Systematic review of the diagnostic value of magnetic resonance imaging for early glottic carcinoma

Objective

In early glottic cancer, accurate assessment of tumor extension, including depth infiltration, is of great importance for both staging, therapeutic approach and systematic comparison of data. Our goal was to assess the diagnostic value of MRI in pre‐therapeutic staging of primary early stage (T1 and T2) glottic carcinoma.

Study design

Systematic review of literature.

Methods

We conducted a systematic search in Pubmed, Embase, and Scopus up to September 23, 2016. Included studies were selected and critically appraised for relevance and validity.

Results

Seven out of 938 unique articles were selected, including 64 cases. MRI over‐staged 6% and under‐staged 13% of cT1 and cT2 tumors. However, available data is heterogeneous, very limited and mainly based on subanalysis of a small amount of patients. Reported MRI protocols appear to be suboptimal for small laryngeal lesions. Diagnostic value of MRI for subtle depth infiltration or laryngeal anatomical subsites (eg, laryngeal ventricle, vocal cord, etc.) could not be assessed.

Conclusions

More studies are needed to assess the diagnostic value of MRI for small glottic tumors.

Comparison of MR Imaging and Dual-Energy CT for the Evaluation of Cartilage Invasion by Laryngeal and Hypopharyngeal Squamous Cell Carcinoma

BACKGROUND AND PURPOSE

Dual-energy CT can distinguish iodine-enhanced tumors from nonossified cartilage and has been investigated for evaluating cartilage invasion in patients with laryngeal and hypopharyngeal squamous cell carcinomas. In this study, we compared the diagnostic accuracy of MR imaging and of a combination of weighted-average and iodine overlay dual-energy CT images in detecting cartilage invasion by laryngeal and hypopharyngeal squamous cell carcinomas, in particular thyroid cartilage invasion.

MATERIALS AND METHODS

Fifty-five consecutive patients who underwent 3T MR imaging and 128-slice dual-energy CT for preoperative initial staging of laryngeal or hypopharyngeal squamous cell carcinomas were included. Two blinded observers evaluated laryngeal cartilage invasion on MR imaging and dual-energy CT using a combination of weighted-average and iodine-overlay images. Pathologic findings of surgically resected specimens were used as the reference standard for evaluating sensitivity, specificity, and the areas under the receiver operating characteristic curve of both modalities for cartilage invasion by each type of cartilage and for all cartilages together. Sensitivity and specificity were compared using the McNemar test and generalized linear mixed models.

RESULTS

Dual-energy CT showed higher specificity than MR imaging for diagnosing all cartilage together (84% for MR imaging versus 98% for dual-energy CT, P < .004) and for thyroid cartilage (64% versus 100%, P < .001), with a similar average area under the curve (0.94 versus 0.95, P = .70). The sensitivity did not differ significantly for all cartilages together (97% versus 81%, P = .16) and for thyroid cartilage (100% versus 89%, P = .50), though there was a trend toward increased sensitivity with MR imaging.

CONCLUSIONS

Dual-energy CT showed higher specificity and acceptable sensitivity in diagnosing laryngeal cartilage invasion compared with MR imaging.

Detection of cartilage invasion in laryngeal carcinoma with dynamic contrast-enhanced CT

Objective

Staging of laryngeal cancer largely depends on cartilage invasion. Presence of cartilage invasion affects treatment choice and prognosis. On MRI and contrast‐enhanced CT (CECT) it may be challenging to differentiate cartilage invasion from inflammation. The purpose of this study is to compare the diagnostic properties of dynamic contrast‐enhanced CT (DCECT) and CECT for visual detection of cartilage invasion in laryngeal cancer.

Study Design

Prospective cohort study.

Methods

Patients with T3 or T4 laryngeal squamous cell carcinoma treated with total laryngectomy were evaluated using 0.625 mm slice CT. DCECT derived permeability and blood volume maps and CECT images were visually evaluated for the presence of invasion of the cartilaginous T‐stage subsites of laryngeal cancer, by detecting continuity with the tumor‐bulk of increased permeability, increased blood volume, and enhancement. Histological evaluation of the surgical total laryngectomy specimen served as the gold standard. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated and compared using the McNemar and Chi‐squared test.

Results

From 14 included patients, a total of 462 subsites were available for T‐stage analysis, of which 84 were cartilage. The median time between CT imaging and total laryngectomy was 1 day (range 1–34 days). There was no significant difference in the detection of cartilage invasion between DCECT and CECT. The sensitivity of CECT was better for all subsites combined (0.85 vs. 0.75; p < 0.01).

Conclusion

DCECT does not improve visual detection of cartilage invasion in T3 and T4 laryngeal cancer compared to CECT.

Level of Evidence

2b, individual cohort study.

Surgical Treatment for Early Stage Glottic Carcinoma with Involvement of the Anterior Commissure

Objective

Assessment of the value of transoral laser microsurgery (TLM) compared with open surgery (OS) for early stage squamous cell carcinoma of the glottic larynx with special regard to involvement of the anterior commissure (AC).

Study Design

Case series with chart review.

Setting

Tertiary care otolaryngology clinic.

Subjects and Methods

Review of clinicopathological data of all patients with previously untreated T1a, T1b, and T2 glottic squamous cell carcinoma of the larynx who were consecutively enrolled over a 10-year period (January 1, 1992, to December 31, 2002).

Results

Local recurrence rate was 20.4% (10 of 49) for TLM and 10.7% (3 of 28) for OS. Comparison of the TLM and OS groups regarding local recurrence rates revealed a significant difference only for tumors invading the AC ( P = .046). Within the TLM group, tumors with involvement of the AC showed a significantly higher recurrence rate (38.1%; 8 of 21) compared with tumors without involvement of the AC (7.1%; 2 of 28; P = .008). In the OS group, involvement of the AC revealed no significant difference ( P = .45). The overall survival in both groups was comparable in both groups (TLM, 93.9%; OS, 89.3%; P = .47).

Conclusion

TLM and OS are equally effective surgical treatments for early stage glottic cancer without involvement of the AC, with selection of treatment based on pretreatment endoscopy. However, TLM is associated with less morbidity. In case of invasion of the AC, OS yields lower recurrence rates.

Effectiveness of ultrasonography and computed tomography in assessing thyroid cartilage invasion in laryngeal and hypopharyngeal cancers

OBJECTIVE

To evaluate the adequacy of ultrasonography (US) and computed tomography (CT) in the assessment of thyroid cartilage invasion in patients with airway cancer.

MATERIALS AND METHODS

Sixty-two consecutive patients referred to our institute underwent US and CT to stage laryngeal (n = 27) or hypopharyngeal (n = 35) cancer in this prospective study. Two radiologists, who were blinded to the patients' clinical histories and histopathology, evaluated thyroid cartilage invasion on US and CT separately and independently. Fifty-eight of the 64 patients (90%) underwent surgery. The histopathologic findings were used as the standard of reference for comparison and statistical analysis.

RESULTS

For thyroid cartilage invasion, the detection rate on CT and US was 98%. CT achieved a sensitivity of 91% and a specificity of 75%, while US attained a sensitivity of 98% and a specificity of 75%. The difference between CT and US in terms of sensitivity was not statistically significant.

CONCLUSION

US and CT have high diagnostic performance in evaluating thyroid cartilage invasion. US is more sensitive than CT in diagnosing invasion of the thyroid cartilage; however, the difference is not statistically significant. US can be used to solve the diagnostic dilemma of the presence or absence of cartilage invasion when CT is inconclusive, as CT is more widely used in staging laryngeal and hypopharyngeal cancers.

Local recurrence of squamous cell carcinoma of the head and neck after radio(chemo)therapy: Diagnostic performance of FDG-PET/MRI with diffusion-weighted sequences

PURPOSE

To determine the diagnostic performance of FDG-PET/MRI with diffusion-weighted imaging (FDG-PET/DWIMRI) for detection and local staging of head and neck squamous cell carcinoma (HNSCC) after radio(chemo)therapy.

MATERIALS AND METHODS

This was a prospective study that included 74 consecutive patients with previous radio(chemo)therapy for HNSCC and in whom tumour recurrence or radiation-induced complications were suspected clinically. The patients underwent hybrid PET/MRI examinations with morphological MRI, DWI and FDG-PET. Experienced readers blinded to clinical/histopathological data evaluated images according to established diagnostic criteria taking into account the complementarity of multiparametric information. The standard of reference was histopathology with whole-organ sections and follow-up ≥24 months. Statistical analysis considered data clustering.

RESULTS

The proof of diagnosis was histology in 46/74 (62.2%) patients and follow-up (mean ± SD = 34 ± 8 months) in 28/74 (37.8%). Thirty-eight patients had 43 HNSCCs and 46 patients (10 with and 36 without tumours) had 62 benign lesions/complications. Sensitivity, specificity, and positive and negative predictive value of PET/DWIMRI were 97.4%, 91.7%, 92.5% and 97.1% per patient, and 93.0%, 93.5%, 90.9%, and 95.1% per lesion, respectively. Agreement between imaging-based and pathological T-stage was excellent (kappa = 0.84, p < 0.001).

CONCLUSION

FDG-PET/DWIMRI yields excellent results for detection and T-classification of HNSCC after radio(chemo)therapy.

KEY POINTS

• FDG-PET/DWIMRI yields excellent results for the detection of post-radio(chemo)therapy HNSCC recurrence. • Prospective one-centre study showed excellent agreement between imaging-based and pathological T-stage. • 97.5% of positive concordant MRI, DWI and FDG-PET results correspond to recurrence. • 87% of discordant MRI, DWI and FDG-PET results correspond to benign lesions. • Multiparametric FDG-PET/DWIMRI facilitates planning of salvage surgery in the irradiated neck.

Computerised tomography and magnetic resonance imaging of laryngeal squamous cell carcinoma: A practical approach

Squamous cell carcinoma is the most common head and neck cancer. This review describes the state-of-the-art computerised tomography and magnetic resonance imaging protocols of the neck and the normal larynx anatomy, and provides a practical approach for the diagnosis and staging of laryngeal squamous cell carcinoma.

Diagnostic accuracy of surface coil MRI in assessing cartilaginous invasion in laryngeal tumours: Do we need contrast-agent administration?

OBJECTIVES

To assess the diagnostic accuracy of MRI performed using surface coils, with and without contrast medium, in predicting thyroid and cricoid cartilage infiltration in laryngeal tumours, and to investigate whether the radiologist's experience influences diagnostic accuracy.

METHODS

We retrospectively enrolled patients with biopsy-proven laryngeal cancer who had undergone preoperative staging MRI and open surgery. Two radiologists with different experience (senior vs. junior) reviewed the MR images without (session A1) and with contrast medium (session A2) separately. We calculated the accuracy of MRI with and without contrast medium in detecting infiltration of the thyroid and cricoid cartilages. Interobserver agreement was calculated by Cohen's Kappa (k).

RESULTS

Forty-two patients were enrolled, for a total of 62 cartilages. In session A1 the senior and junior radiologists showed an accuracy of 85% and 71%, respectively, with k = 0.53 (0.33-0.72). In session A2 the senior and junior radiologists showed an accuracy of 84% and 77%, respectively, with k = 0.68 (0.49-0.86).

CONCLUSIONS

Staging of laryngeal tumours with surface coil MRI showed good diagnostic accuracy in assessing cartilaginous infiltration. We observed similar values of diagnostic accuracy for the analysis performed with and without contrast medium for the senior radiologist.

KEY POINTS

• Surface coil MRI demonstrated good accuracy in assessing laryngeal cartilage invasion. • The radiologist's experience can influence the diagnostic accuracy. • Gadolinium administration may increase interobserver concordance.

Dual-Energy CT in Head and Neck Imaging

PURPOSE OF REVIEW

To explain the technique of Dual-energy CT (DECT) and highlight its applications and advantages in head and neck radiology.

RECENT FINDINGS

Using DECT, additional datasets can be created next to conventional images. In head and neck radiology, three material decomposition algorithms can be used for improved lesion detection and delineation of the tumor. Iodine concentration measurements can aid in differentiating malignant from nonmalignant lymph nodes and benign posttreatment changes from tumor recurrence. Virtual non-calcium images can be used for detection of bone marrow edema. Virtual mono-energetic imaging can be useful for improved iodine conspicuity at lower keV and for reduction of metallic artifacts and increase in signal-to-noise ratio at higher keV.

SUMMARY

DECT and its additional reconstructions can play an important role in head and neck cancer patients, from initial diagnosis and staging, to therapy planning, evaluation of treatment response and follow-up. Moreover, it can be helpful in imaging of infections and inflammation and parathyroid imaging as supplementary reconstructions can be obtained at lower or equal radiation dose compared with conventional single energy scanning.