Nodal imaging in the neck: recent advances in US, CT and MR imaging of metastatic nodes

Radiomics from dual-energy CT-derived iodine maps predict lymph node metastasis in head and neck squamous cell carcinoma

OBJECTIVE

To develop and validate an iodine maps-based radiomics nomogram for preoperatively predicting cervical lymph node metastasis (LNM) in head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

A total of 278 patients who pathologically confirmed as HNSCC were retrospectively recruited from two medical centers between June 2012 and July 2022. The training set (n = 152) and internal set (n = 67) were randomly selected from medical center A, and the patients from medical center B were enrolled as the external set (n = 69). The minority group in the training set was balanced by the adaptive synthetic sampling (ADASYN) approach. Radiomics features were extracted from dual-energy CT-derived iodine maps at arterial phase (AP) and venous phase (VP), respectively. Three radiomics signatures were constructed to predict the LNM by using a random forest algorithm. The independent clinical predictors for LNM were identified by multivariate analysis and combined with radiomics signatures to establish a radiomic-clinical nomogram. The performance of radiomic-clinical nomogram was evaluated with respect to its discrimination and clinical usefulness.

RESULTS

The AP-VP-incorporated radiomics model exhibited a great predictive performance for LNM prediction with an area under curve (AUC) of 0.885 (95% CI, 0.836-0.933) in ADASYN-training set and confirmed in all validation sets. The nomogram that incorporated AP-VP radiomics signatures, CT-reported LN status, and histological grades yielded AUCs of 0.920 (95% CI, 0.881-0.959) in ADASYN-training set, 0.858 (95% CI, 0.771-0.944) in internal validation, and 0.849 (95% CI, 0.752-0.946) in external validation, with good calibration in all cohorts (p > 0.05). Decision curve analyses indicated the nomogram was clinically useful. In addition, the predictive performance of clinical-radiomics nomogram was also validation in combing cohorts. Stratified analysis confirmed the stability of nomogram, particularly in group negative for CT-reported LNM.

CONCLUSION

Clinical-radiomics nomogram based on iodine maps exhibited promising performance in predicting LNM and providing valuable information for making individualized therapy decisions.

Metastatic Lymph Node Detection on Ultrasound Images Using YOLOv7 in Patients with Head and Neck Squamous Cell Carcinoma

Ultrasonography is the preferred modality for detailed evaluation of enlarged lymph nodes (LNs) identified on computed tomography and/or magnetic resonance imaging, owing to its high spatial resolution. However, the diagnostic performance of ultrasonography depends on the examiner's expertise. To support the ultrasonographic diagnosis, we developed YOLOv7-based deep learning models for metastatic LN detection on ultrasonography and compared their detection performance with that of highly experienced radiologists and less experienced residents. We enrolled 462 B- and D-mode ultrasound images of 261 metastatic and 279 non-metastatic histopathologically confirmed LNs from 126 patients with head and neck squamous cell carcinoma. The YOLOv7-based B- and D-mode models were optimized using B- and D-mode training and validation images and their detection performance for metastatic LNs was evaluated using B- and D-mode testing images, respectively. The D-mode model's performance was comparable to that of radiologists and superior to that of residents' reading of D-mode images, whereas the B-mode model's performance was higher than that of residents but lower than that of radiologists on B-mode images. Thus, YOLOv7-based B- and D-mode models can assist less experienced residents in ultrasonographic diagnoses. The D-mode model could raise the diagnostic performance of residents to the same level as experienced radiologists.

Characterizing perfusion defects in metastatic lymph nodes at an early stage using high-frequency ultrasound and micro-CT imaging

A perfusion defect in a metastatic lymph node (LN) can be visualized as a localized area of low contrast on contrast-enhanced CT, MRI or ultrasound images. Hypotheses for perfusion defects include abnormal hemodynamics in neovascular vessels or a decrease in blood flow in pre-existing blood vessels in the parenchyma due to compression by LN tumor growth. However, the mechanisms underlying perfusion defects in LNs during the early stage of LN metastasis have not been investigated. We show that tumor mass formation with very few microvessels was associated with a perfusion defect in a non-enlarged LN at the early stage of LN metastasis in a LN adenopathy mouse (LN size circa 10 mm). We found in a mouse model of LN metastasis, induced using non-keratinizing tumor cells, that during the formation of the perfusion defect in a non-enlarged LN, the number of blood vessels ≤ 50 μm in diameter decreased, while those of > 50 μm in diameter increased. The methods used were contrast-enhanced high-frequency ultrasound and contrast-enhanced micro-CT imaging systems, with a maximum spatial resolution of > 30 μm. Furthermore, we found no tumor angiogenesis or oxygen partial pressure (pO₂) changes in the metastatic LN. Our results demonstrate that the perfusion defect appears to be a specific form of tumorigenesis in the LN, which is a vascular-rich organ. We anticipate that a perfusion defect on ultrasound, CT or MRI images will be used as an indicator of a non-enlarged metastatic LN at an early stage.

Prognostic role of primary tumor, nodal neck, and retropharyngeal GTVs for unresectable sinonasal cancers treated with IMRT and chemotherapy

Background:

We evaluated the prognostic role of gross tumor volumes (GTVs) of primary tumor and positive lymph nodes on overall survival (OS) and progression-free survival (PFS) in locally advanced unresectable sinonasal cancer (SNC) treated with definitive intensity-modulated radiotherapy (IMRT) with or without chemotherapy.

Methods:

Primary tumor GTV (GTV-T), pathologic neck nodes GTV (GTV-N), and positive retropharyngeal nodes GTV (GTV-RPN) of 34 patients with epithelial nonglandular SNC receiving IMRT with or without chemotherapy were retrospectively measured. The GTV variables were analyzed in relation with OS and PFS. Survival curves were estimated using the Kaplan-Meier method and compared with the log-rank test. We also estimated the crude cumulative incidence of locoregional relapses only. The optimal volume cutoff value was determined using an outcome-oriented method among the observed values.

Results:

GTV-T was significantly associated with decreased OS ( P=0.003) and PFS ( P=0.003). Moreover, patients with disease total volumes (GTV) smaller than 149.44 cm³ had better OS and PFS than patients with higher volumes ( P<0.0001 for both). Neck nodal metastasis impacted on OS and PFS ( P=0.030 and P=0.033, respectively), but GTV-N did not ( P=0.961; P=0.958). Retropharyngeal nodes metastasis was not associated with prognosis (OS: P=0.400; PFS: P=0.104). When GTV-RPN was added to GTV-N (GTV-TN), a relation with PFS ( P=0.041) and a trend toward significance for OS ( P=0.075) were found.

Conclusions:

Our results show that tumor volume is a powerful predictor of outcome in SNC. This could be useful to identify patients with worse prognosis deserving different treatment strategies.

[Influence of external and endogenous factors on cervical lymph nodes : Sonographic study of size and morphology]

BACKGROUND

Sonographic evaluation of the dignity of cervical lymph nodes is essential for further diagnostics and treatment concepts in various diseases. The aim of this prospective monocenter study was to determine the sonomorphology and size of benign changes of lymph nodes in healthy subjects and patients who had undergone surgery, in order to examine the influence of various factors.

MATERIALS AND METHODS

Data from 205 healthy subjects and 15 patients before and after surgery were analyzed. Sonographically representative lymph nodes were measured in diameter and volumes were calculated; margins, the recognizability of a hilus, and vascularization were documented. A detailed medical history was taken using a standardized questionnaire.

RESULTS

In 20-39-year-olds, lymph node diameters were larger than in 40-59- and over 60-year-olds, and in 40-59-year-olds, the lymph nodes were larger than over 60-year-old subjects. Individuals with consumption of less than 10 and 10-20 cigarettes per day showed larger cervical lymph nodes compared to subjects with a consumption of more than 20 cigarettes per day. Smokers who additionally exercised routinely showed larger lymph nodes than those who never smoked or exercised. In addition, we observed that both the size and the number of cervical lymph nodes increased postoperatively compared to preoperative.

CONCLUSION

The recorded lymph nodes corresponded to the established sonographic criteria of benign lymph nodes. Our results show that age, smoking intensity, combination of smoking with sporting activity, and surgery influence the size of sonographically measured cervical lymph nodes.

Kikuchi-Fujimoto disease in the regional lymph nodes with node metastasis in a patient with tongue cancer: A case report and literature review

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare self-limiting disorder typically affecting the cervical lymph nodes (LNs), which is often misdiagnosed as other LN-associated diseases. KFD frequently presents with necrotic lesions and recurrences, which are also features of metastatic LNs. Clinicians may thus suspect LN metastasis when they encounter ipsilateral cervical lymphadenopathy in a patient with head and neck cancer. The present study reports the case of a 48-year-old man with tongue cancer and KFD affecting the right edge of his tongue and ipsilateral cervical LNs. LN metastasis was initially suspected, but pathological examination of the dissected LNs revealed one necrotic metastatic lesion and two necrotic KFD lesions. Ipsilateral cervical lymphadenopathy recurred 6 years after the initial surgery, and it was not possible to differentiate clinically between a second primary tumor and recurrent KFD prior to treatment. To the best of our knowledge, this is the first reported case of simultaneous tongue cancer, regional LN metastasis and KFD. This highlights the requirement to consider KFD in the event of LNs with necrotic lesions but no cancerous cells. A combination of clinical and pathological approaches may aid in the diagnosis of KFD, in addition to ruling out LN metastasis in initial and recurrent lymphadenopathies. The present study indicate that a diagnosis of KFD should be considered in patients with head and neck cancer that exhibit necrotic LNs lacking cancerous cells. This is important, as misdiagnosis of KFD as LN metastasis may lead to unnecessary adjuvant therapy.

Impact of 3T multiparametric MRI and FDG-PET-CT in the evaluation of occult primary cancer with cervical node metastasis

Background

This study aimed to determine the ability of multimodal evaluation with multiparametric 3T-MRI (MPMRI) and positron emission tomography - computed tomography (PET/CT) to detect cancer of unknown primary origin (CUP) with neck lymph node (LN) metastasis.

Methods

The study group comprised 38 retrospectively analysed consecutive patients with LN metastasis in the head and neck (HN) region without known primary tumours (PTs). Statistical values of 3T-MRI and of FDG-PET/CT scans were evaluated.

Results

Of the 38 CUPs, conventional native T1-, T2-weighted and STIR sequences detected 6 PTs. Native sequences plus diffusion-weighted imaging (DWI) found 14-, and with fat suppression contrast-enhanced T1-weighted measurement as well as with the complex MPMRI found 15 primaries and with PET/CT 17 CUPs could be evaluated, respectively. The detection rates were 15.8, 36.8, 39.5, 39.5 and 44.7 % for conventional native MRI, native plus DWI, native with contrast-enhanced MRI (CE-MRI), for MPMRI, and for PET/CT, respectively. The overall detection rate proved by histology was 47.4 %. PET/CT provided the highest sensitivity (Sv: 94.4 %) but a lower specificity (Sp: 65.0 %), using MPMRI (Sv: 88.2 %) the specificity increased to 71.4 %. DWIincreased specificity of the native sequences (Sp: 76.2 %). Conventional native sequences plus DWI as well as 3T-MPMRI and PET/CT were same accurate (Acc: 79.0 %) and had similar likelihood ratio (LR: 3.42, 3.03 and 2.62) in detecting unknown PT sites.

Conclusions

The accuracy of FDG-PET/CT and MPMRI in case of CUP in finding the primary cancer in the neck regions is identical. While using PET/CT whole body information can be obtained in one examination. MPMRI shows the local soft tissue status more accurately. In cases of CUP PET/CT should be the first method of choice if it is available. MPMRI can clarify the exact primary tumor stage, and it can be advantageous in clarifying the prognostic factors, which is necessary in case of advanced tumor stage and when surgery is under consideration. In case low N stage is likely after the clinical examination and wait and see policy can be considered, MPMRI is recommended, and in this case the significance the of radiation free MPMRI is increasing.

Electronic supplementary material

The online version of this article (doi:10.1186/s40644-016-0097-x) contains supplementary material, which is available to authorized users.

The diagnostic value of 1.5-T diffusion-weighted MR imaging in detecting 5 to 10 mm metastatic cervical lymph nodes of nasopharyngeal carcinoma

The aim of the study was to prospectively assess the diagnostic accuracy of 1.5 T diffusion-weighted imaging (DWI) for 5 to 10 mm metastatic cervical lymph nodes of patients with nasopharyngeal carcinoma (NPC). All patients with histopathologically confirmed NPC underwent DWI with 2 b values of 0 and 800 s/mm were enrolled. The shortest axial diameter and mean apparent diffusion coefficient (ADC) value were recorded when lymph nodes with a shortest axial diameter from 5 to 10 mm were measured. The correlation between the pathological diagnoses and mean ADC values in the benign and metastatic lymph nodes were compared using the Z test. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of DWI. Three hundred fourteen nodes of 52 patients with NPC consisted of 46.5% (146/314) metastatic lymph nodes and 53.5% (168/314) benign lymph nodes. The mean ADC value (×10 mm/s) of benign lymph nodes was (1.110 ± 0.202), which was significantly higher than that of metastatic nodes (0.878 ± 0.159) (P < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value, accuracy for differentiating metastatic from benign lymph nodes using a cutoff ADC value of 0.924 × 10 mm/s was 83.56%, 82.74%, 80.79%, 85.28%, and 82.80%, respectively. The area under the ROC curve was 0.851 (95% confidence intervals: 0.807-0.889). This study demonstrated that DWI is helpful in detecting 5 to 10 mm metastatic lymph nodes of patients with NPC.

Pre-radiotherapy Haemoglobin Level is A Prognosticator in Locally Advanced Head and Neck Cancers Treated with Concurrent Chemoradiation

INTRODUCTION

Radiation plays a major role in treatment of locoregional control of Head and Neck Squamous cell carcinoma (HNSCC). Anaemia is considered a contributor to intra-tumour hypoxia and tumour resistance to ionizing radiation and most evidences are from developed world, we prospectively investigated the exact role of anaemia in treatment outcome of Stage III/IVA HNSCC in our patient population.

AIM OF THE STUDY

Primary end point: To analyse the Pre-Radiotherapy haemoglobin level and early response of treatment in stage III/IVA HNSCC and to determine the relationship of Pre-Radiotherapy haemoglobin level with other prognostic factors.

MATERIALS AND METHODS

This non-interventional single blinded randomized study enrolled patients attending the OPD consecutively, who met our eligibility criteria.

INCLUSION CRITERIA

HNSCC patients of Stage III/IVA aged ≥18 years and ≤ 70 years with ECOG status of 1or 2 and willing for concurrent chemoradiation and at least 6 weeks of follow up.

EXCLUSION CRITERIA

1) Previous history of treatment for malignancy or radiation in head and neck site. 2) Patients with other fatal and non-fatal pre-morbid or co-morbid conditions that can affect the outcome or the overall survival. Patients with Pre-radiotherapy haemoglobin status < 10 g/dl were given haematinic support and/or blood transfusion. All patients received concurrent chemotherapy (weekly cisplatin) and radiation in conventionally fractionated dose of 66Gy. Early treatment responses were evaluated with Revised RECIST version 1.1 and Data analysis using SPSS version 17.0.

RESULTS

Ninety one patients enrolled had mean age of 55.63 (range: 32-69), a median of 56 and mode of 60. Seventy one were males (78%) and 20 females (22%) with a performance status of ECOG 1 in 43 (47%) patients and ECOG 2 in 48 (53%); Pre-RT Hb level of <10.7 g/dl in 38 (42%) patients and ≥10.7 in 53 (58%) patients; Pre-RT Hb level was <12 g/dl in 67 (74%) patients and ≥12 in 24 (26%) patients. Tumour sites were - Nasopharynx 7 (8 %), Oral Cavity 18 (20 %), Oropharynx 32 (35 %), Hypopharynx 23 (25 %) and Larynx 11 (12 %). Twenty five (27%) had Grade 2 mucositis and 66 (73%) had Grade 3 mucositis. Fifty eight (64%) patients completed treatment with NO breaks and 33 (36%) with treatment breaks for ≥5 days. Pre-radiotherapy haemoglobin ≥ 10.7 g/dl (p < 0.001), ECOG performance status (p = 0.0002), Treatment interruptions for > 5 days (p = <0.0001), Mucositis reaction (p = <0.0001) showed statistical significance with outcome of response.

CONCLUSION

The study found that performance status, pre-RT haemoglobin level, radiotherapy interruptions > 5 days and non-development of grade III mucositis was found to be significantly associated with good loco-regional control. Haemoglobin level ≥10.7 g/dl was associated with better treatment outcome, higher performance status, fewer treatment interruptions and lesser degree of mucositis. Transfusion did not affect the outcome. Definitive conclusions and recommendations need further expansion of our study for better statistical power.

Cutaneous malignancy of the head and neck

Most skin cancers of the head and neck are nonmelanoma skin cancers (NMSCs). Basal cell carcinoma and squamous cell carcinoma are the most frequent types of NMSCs. Treatment options including wide local excision, Mohs surgery, sentinel lymph node biopsy, and cervical lymphadenectomy and adjuvant radiation when warranted offer a high cure rate, while balancing excellent functional and cosmetic outcomes. Evaluation by a multidisciplinary team is highly recommended with advanced and aggressive lesions. Avoidance of sunburns and acute sun damage, sunscreen protection, and early identification and evaluation of suspicious lesions remain the first line of defense against skin cancers.

Imaging of head and neck lymph nodes

The cervical lymph nodes can be affected by a variety of infectious, inflammatory, benign, and malignant pathologic conditions. Clinical history and physical examination with the complementary use of imaging is essential to accurately make a diagnosis or appropriate differential. Knowledge of cervical lymph node anatomy, drainage pathways, morphologic variations, and common nodal pathology is key to correct interpretation of cervical lymph nodes on imaging. Computed tomography (CT), MR, ultrasound, and PET/CT are complementary imaging modalities that can be used in the evaluation of cervical lymph node pathology.

Prognostic factors in advanced pharyngeal and oral cavity cancer; significance of multimodality imaging in terms of 7th edition of TNM

As with most cancers the prognosis in pharyngeal and oral cavity cancer largely depends on tumour stage. Physical examination, including endoscopy should be combined with technical radiologic imaging to record the precise extent of tumour. The TNM staging system of the head and neck region is, in fact, an anatomic staging system that describes the anatomic extent of the primary tumour as well as the involvement of regional lymph nodes and distant metastases. Modifications in the TNM staging system should consider not only the expert opinions and published reports in the literature but the technical advances in technology for improved assessment of tumour extent and the shifting paradigms in therapeutic strategies. “T” stage of the tumour is defined by its size, the depth of the invasion and the involvement of vital structures. In the 7th edition of TNM classification, for stage T4 tumors (larger than 4 cm), subcategories a and b were introduced to indicate the involvement of vital structures and their suitability for surgical resection (except for nasopharynx cancer). Nodal metastasis is the most important predictor of outcome for squamous cell cancer of the head and neck.

Better and more reliable methods of pretreatment tumour assessment are therefore crucial to ensure that the clinical assessment of tumor approximates its actual pathologic extent.

CT and MRI are both useful for assessing extensions of pharyngeal- and oral cavity cancer in advanced stage. MRI is superior in visualizing most primary tumour sites.

Prognostic factors in patients with head and neck squamous cell carcinoma with cN3 neck disease: a retrospective case-control study

OBJECTIVE

This study examined prognostic factors in patients with head and neck squamous cell carcinoma with advanced neck disease.

STUDY DESIGN

The records of 191 patients with previously untreated head and neck squamous cell carcinoma and metastatic cervical lymph node (LN) >6 cm (cN, n = 70) and 3.01 to 6 cm (control, n = 121) in the greatest dimension were reviewed. Univariate and multivariate analyses were used to identify factors associated with disease-free survival (DFS) and locoregional control (LRC).

RESULTS

In the cN3 group, independent variables for DFS were age, active drinking, LN size, and extranodal extension (P < .05), and that for LRC was age (P = .025). In the control group, independent variables for DFS were tumor location and differentiation and LN bilaterality (P < .05), and that for LRC was LN bilaterality (P = .011).

CONCLUSIONS

The survival of cN3 patients is affected by host and nodal characteristics including age, drinking, nodal size, and extranodal extension.

Comparison of dual-energy CT-derived iodine content and iodine overlay of normal, inflammatory and metastatic squamous cell carcinoma cervical lymph nodes

OBJECTIVES

To evaluate whether dual-energy computed tomography (DECT)-derived iodine content and iodine overlay could differentiate between normal, inflammatory and metastatic squamous cell carcinoma (SCC) cervical lymph nodes.

METHODS

This study was approved by the institutional review board. Sixteen patients with normal lymph nodes, 20 patients with enlarged nodes draining deep cervical inflammations and 23 patients with pathologically proved metastatic SCC nodes who underwent contrast enhanced DECT were retrospectively identified. Iodine content and overlay of 36 normal, 43 inflammatory and 52 metastatic lymph nodes were calculated using circular regions of interest and compared among the three groups. A receiver operating characteristic (ROC) curve was used to determine the sensitivity and specificity of iodine content and overlay for diagnosis of metastatic nodes.

RESULTS

Iodine content (mg/ml) was significantly lower for metastatic lymph nodes (2.34 ± 0.45) than for normal (2.86 ± 0.37) and inflammatory (3.53 ± 0.56) lymph nodes, P < 0.0001. Iodine overlay (HU) was also significantly lower for metastatic lymph nodes (47 ± 11.6) than normal (57.4 ± 8.2) and inflammatory nodes (69.3 ± 11.5), P < 0.0001. The areas under the ROC curve for iodine content and iodine overlay were 0.923 and 0.896.

CONCLUSIONS

DECT-derived iodine content and overlay differ significantly among normal, inflammatory and metastatic SCC cervical lymph nodes.

KEY POINTS

• Derived iodine content can be calculated from contrast-enhanced dual-energy CT. • Derived iodine content and iodine overlay could help characterise cervical lymph nodes. • Iodine parameters were significantly lower in metastatic lymph nodes than normal/inflammatory lymph nodes. • Iodine content appears more sensitive than iodine overlay for lymph node characterisation.

Prognostic significance of preoperative metabolic tumour volume and total lesion glycolysis measured by (18)F-FDG PET/CT in squamous cell carcinoma of the oral cavity

PURPOSE

Metabolic tumour volume (MTV) and total lesion glycolysis (TLG) from (18)F-FDG PET/CT are emerging prognostic biomarkers in human solid cancers; yet few studies have investigated their clinical and prognostic significance in oral cavity squamous cell carcinoma (OSCC). The present retrospective study evaluated the utility of pretreatment MTV and TLG measured by (18)F-FDG PET/CT to predict survival and occult metastasis (OM) in OSCC.

METHODS

Of 162 patients with OSCC evaluated preoperatively by (18)F-FDG PET/CT, 105 who underwent definitive surgery with or without adjuvant therapy were eligible. Maximum standardized uptake value (SUVmax), MTV and TLG were measured. For calculation of MTV, 3-D regions of interest were drawn and a SUV threshold of 2.5 was used for defining regions. Univariate and multivariate analyses identified clinicopathological and imaging variables associated with OM, disease-free survival (DFS) and overall survival (OS).

RESULTS

The median (range) SUVmax, MTV and TLG were 7.3 (0.7-41.9), 4.5 ml (0.7-115.1 ml) and 18.3 g (2.4-224.1 g), respectively. Of 53 patients with clinically negative lymph nodes, OM was detected in 19 (36%). By univariate and multivariate analyses, MTV (P = 0.018) and TLG (P = 0.011) were both independent predictive factors for OM, although they were not independent of each other. The 4-year DFS and OS rates were 53.0% and 62.0%, respectively. Univariate and multivariate analyses revealed that MTV (P = 0.001) and TLG (P = 0.006), with different cut-off levels, were both independent predictive factors for DFS, although they were not independent of each other, and MTV (P = 0.001), TLG (P = 0.002) and the involved resection margin (P = 0.007) were independent predictive factors for OS.

CONCLUSION

Pretreatment MTV and TLG may be useful in stratifying the likelihood of survival and predicting OM in OSCC.

Head and neck tumours: combined MRI assessment based on IVIM and TIC analyses for the differentiation of tumors of different histological types

OBJECTIVES

We evaluated the combined use of intravoxel incoherent motion (IVIM) and time-signal intensity curve (TIC) analyses to diagnose head and neck tumours.

METHODS

We compared perfusion-related parameters (PP) and molecular diffusion values (D) determined from IVIM theory and TIC profiles among 92 tumours with different histologies.

RESULTS

IVIM parameters (f and D values) and TIC profiles in combination were distinct among the different types of head and neck tumours, including squamous cell carcinomas (SCCs), lymphomas, malignant salivary gland tumours, Warthin's tumours, pleomorphic adenomas and schwannomas. A multiparametric approach using both IVIM parameters and TIC profiles differentiated between benign and malignant tumours with 97 % accuracy and diagnosed different tumour types with 89 % accuracy.

CONCLUSIONS

Combined use of IVIM parameters and TIC profiles has high efficacy in diagnosing head and neck tumours.

KEY POINTS

• Head and neck tumours have wide MR perfusion/diffusion properties. • Dynamic contrast-enhanced (DCE) MR imaging can characterise tumour perfusion (TIC analysis). • Intravoxel incoherent motion (IVIM) imaging can provide diffusion and perfusion properties. • However, IVIM or DCE imaging alone is insufficient for diagnosing head/neck tumours. • Multiparametric approach using both IVIM and TIC profiles can facilitate the diagnosis.

Can axial-based nodal size criteria be used in other imaging planes to accurately determine "enlarged" head and neck lymph nodes?

Objective. We evaluate if axial-based lymph node size criteria can be applied to coronal and sagittal planes. Methods. Fifty pretreatment computed tomographic (CT) neck exams were evaluated in patients with head and neck squamous cell carcinoma (SCCa) and neck lymphadenopathy. Axial-based size criteria were applied to all 3 imaging planes, measured, and classified as “enlarged” if equal to or exceeding size criteria. Results. 222 lymph nodes were “enlarged” in one imaging plane; however, 53.2% (118/222) of these were “enlarged” in all 3 planes. Classification concordance between axial versus coronal/sagittal planes was poor (kappa = −0.09 and −0.07, resp., P < 0.05). The McNemar test showed systematic misclassification when comparing axial versus coronal (P < 0.001) and axial versus sagittal (P < 0.001) planes. Conclusion. Classification of “enlarged” lymph nodes differs between axial versus coronal/sagittal imaging planes when axial-based nodal size criteria are applied independently to all three imaging planes, and exclusively used without other morphologic nodal data.

Necrotic cervical nodes: usefulness of diffusion-weighted MR imaging in the differentiation of suppurative lymphadenitis from malignancy

PURPOSE

The purpose of this study was to assess the efficacy of diffusion-weighted (DW) MR imaging for the differentiation between suppurative lymphadenitis and malignancy in necrotic cervical lymph nodes.

MATERIALS AND METHODS

Fifteen patients with suppurative lymphadenitis, 40 with squamous cell carcinoma (SCC), eight with lymphoma, and six with thyroid cancer were accompanied by necrotic cervical nodes. All 69 patients underwent 1.5-T MR imaging including DW and 58 underwent gadolinium-enhanced MR imaging. Necrotic area-to-spinal cord signal intensity ratios (SIR) on T1-, T2- and DW images and apparent diffusion coefficients (ADCs) [10(-3)mm(2)/s] were correlated with the pathologies.

RESULTS

Nineteen necrotic cervical nodes with suppurative lymphadenitis, 67 with SCC, 10 with lymphoma, and 12 with thyroid cancer were identified. SIR on DW images was higher in suppurative lymphadenitis (2.50 ± 1.21) than in malignancies (1.29 ± 0.67) (p<.01), and ADC value was lower in suppurative lymphadenitis (0.89 ± 0.21) than in malignancies (1.46 ± 0.46) (p<.01). SIR on T1-weighted images was higher in thyroid cancer (1.95 ± 0.53) than in suppurative lymphadenitis (0.87 ± 0.17), SCC (0.92 ± 0.13), and lymphoma (0.95 ± 0.09) (p<.01). No significant difference in SIR on T2-weighted images was found between suppurative lymphadenitis (1.46 ± 0.50) and malignancies (1.61 ± 0.56).

CONCLUSION

DW imaging with ADC measurements may play a supplementary role in the differentiation of necrotic cervical nodes between suppurative lymphadenitis and malignancy.

Extranodal spread in the neck: MRI detection on the basis of pixel-based time-signal intensity curve analysis

PURPOSE

We evaluated dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) for the preoperative detection of extranodal spread (ENS) in metastatic nodes in the neck.

MATERIALS AND METHODS

The time-signal intensity curve (TIC) profiles of 54 histologically proven metastatic nodes (26 ENS-positive and 28 ENS-negative) from 43 patients with head and neck squamous cell carcinoma (SCC) were retrospectively analyzed to determine the effective TIC criteria for ENS-positive nodes. The TICs were semiautomatically classified into four distinctive patterns (flat, slow uptake, rapid uptake with low washout ratio, and rapid uptake with high washout ratio) on a pixel-by-pixel basis.

RESULTS

A number of the MRI findings were significantly correlated with ENS. However, multivariate logistic regression analysis revealed that only a short-axis diameter and an area with slow uptake TIC patterns were significantly and independently indicative of the presence of ENS. The combined MRI criteria of nodal size (>25 mm) or TIC profile (>44% nodal areas with slow-uptake TIC patterns) yielded the best results for differentiation between ENS-positive and ENS-negative nodes, providing 96% sensitivity, 100% specificity, 98% accuracy, and 100% positive, and 97% negative predictive values.

CONCLUSION

When combined with size criteria, pixel-based MR factor analysis may be a promising tool for detecting ENS.

Head and neck cancers manifested as deep neck infection

The incidence of head and neck cancers in patients with an initial presentation of deep neck infection is unclear and may be underestimated. Thus, the aim of this study was to assess the incidence of head and neck cancers initially manifested as deep neck infection. Also, the possible risk factors and pathophysiology are discussed. This study was a retrospective medical chart review in a tertiary referral center. A total of 81 consecutive patients admitted with a diagnosis of deep neck infection over a 46-month period were analyzed. The demographic data, physical examinations, laboratory findings, radiographic studies, and pathology report were analyzed. Among the 81 deep neck infection patients, head and neck cancers were histologically demonstrated in four patients (4.9%) with the initial symptom of a painful neck mass. The incidence of head and neck cancer initially manifested as deep neck infection was found to increase in patients aged over 40 years (6.7%; 3/45 vs. 2.8%; 1/36). A detailed history of all patients with deep neck infection should be taken. Furthermore, endoscopic examination, thyroid examination and routine pathological examination should be performed, especially in those aged over 40. Also, careful explanation to the patient and his/her family about the possibility of underlying head and neck cancer (incidence 1-5%) may be needed. If the neck swelling diminishes, but does not disappear completely after full course of antibiotics, repeated fine needle aspiration, endoscopy, or image study should be considered.

Role of perfusion magnetic resonance imaging in cervical lymphadenopathy

PURPOSE

To assess the role of perfusion magnetic resonance (MR) imaging in patients with cervical lymphadenopathy.

MATERIALS AND METHODS

Dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging was performed on 45 cervical lymph nodes after a bolus injection of gadolinium-DTPA (0.1 mmol/kg body weight). Time signal intensity curve was created and dynamic susceptibility contrast (DSC) percentage of the lymph nodes was calculated. Receiver operating characteristic curve analysis was used to investigate whether DSC percentage could aid in the characterization of cervical lymphadenopathy.

RESULTS

The mean (SD) DSC percentage of malignant nodes (44.8% [6.2%]) was significantly different (P = 0.001) from that of benign nodes (28.8% [4.8%]). The mean (SD) DSC percentage of metastatic nodes (48.72% [2.4%]) was significantly different (P = 0.001) than that of lymphoma (37.09% [3.5%]). The DSC percentage threshold value used for differentiating malignant from benign nodes and metastatic from lymphomatous nodes were 34.3% and 43.5%, with areas under the curve of 0.95 and 0.97, respectively.

CONCLUSIONS

Perfusion MR imaging is a noninvasive promising method that can be used for differentiation of malignant from benign cervical lymph nodes, and it helps in the characterization of malignant cervical lymphadenopathy.

Head and neck cancer: carcinoma of unknown primary

Carcinoma of unknown primary is uncommon, estimated to represent only 3% to 5% of all head and neck cancers. Squamous cell carcinoma accounts for 70% to 90% of these lesions, most commonly from sites in the upper aerodigestive tract, including tonsils, base of tongue, nasopharynx, and piriform sinus. Magnetic resonance, computed tomography (CT), and positron emission tomography all play a role in the assessment of patients with an unknown primary. The location of a metastatic lymph node may give an indication of the primary tumor site, and knowledge of lymph node drainage patterns is important for anyone evaluating these patients. Magnetic resonance and CT are both used for evaluation for extracapsular nodal disease, perineural tumor spread, osseous skull base or perivertebral space involvement, and vascular invasion, findings that seriously impact treatment and prognosis. Positron emission tomography/CT also plays a significant role in detecting primary tumor sites and identifying distant metastatic disease.

Detection of small inflammatory and metastatic lymph nodes in rabbits by sonography: evaluation with the resistive index ratio

OBJECTIVE

The aim of this prospective study was to determine whether the resistive index (RI) ratio based on high-resolution spectral Doppler sonography would be useful in the differential diagnosis of small inflammatory and metastatic lymph nodes in rabbit models.

METHODS

The infected and metastatic lymph node models we used were created by subcutaneously inoculating methicillin-susceptible Staphylococcus aureus and VX2 tumor cells respectively into the left hind limbs of 10 New Zealand White rabbits. High-resolution sonography was performed to investigate the popliteal fossa lymph nodes 2 weeks after the inoculation. The sizes, long-/short-axis ratios, and RI ratios (defined as the value of the peripheral RI relative to the central RI) of the nodes were evaluated with sonography and then compared with the histopathologic findings.

RESULTS

No statistical differences were found between the volumes (mean +/- SD, 104 +/- 41 versus 87 +/- 24 mm(3); P > .05) and the long-/short-axis ratios (1.97 +/- 0.28 versus 2.03 +/- 0.26; P > .05) of 15 inflammatory and 14 metastatic lymph nodes. On spectral Doppler sonography, the RI ratio was higher in the metastatic lymph nodes than in the inflammatory lymph nodes. With an RI ratio higher than 1.2 as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity, and positive and negative predictive values of sonography were 71% (10/14), 80% (12/15), 76% (10/13), and 75% (12/16), respectively, with an area under the receiver operating characteristic curve value of 0.824.

CONCLUSIONS

This experimental study confirms that RI ratio changes based on high-resolution spectral Doppler sonography are associated with histopathologic changes of metastatic and inflammatory lymph nodes during the initial stage in rabbits.