Modern imaging lymph node staging of the head and neck region

Development and Validation of a 3D Resnet Model for Prediction of Lymph Node Metastasis in Head and Neck Cancer Patients

The accurate diagnosis and staging of lymph node metastasis (LNM) are crucial for determining the optimal treatment strategy for head and neck cancer patients. We aimed to develop a 3D Resnet model and investigate its prediction value in detecting LNM. This study enrolled 156 head and neck cancer patients and analyzed 342 lymph nodes segmented from surgical pathologic reports. The patients' clinical and pathological data related to the primary tumor site and clinical and pathology T and N stages were collected. To predict LNM, we developed a dual-pathway 3D Resnet model incorporating two Resnet models with different depths to extract features from the input data. To assess the model's performance, we compared its predictions with those of radiologists in a test dataset comprising 38 patients. The study found that the dimensions and volume of LNM + were significantly larger than those of LNM-. Specifically, the Y and Z dimensions showed the highest sensitivity of 84.6% and specificity of 72.2%, respectively, in predicting LNM + . The analysis of various variations of the proposed 3D Resnet model demonstrated that Dual-3D-Resnet models with a depth of 34 achieved the highest AUC values of 0.9294. In the validation test of 38 patients and 86 lymph nodes dataset, the 3D Resnet model outperformed both physical examination and radiologists in terms of sensitivity (80.8% compared to 50.0% and 91.7%, respectively), specificity(90.0% compared to 88.5% and 65.4%, respectively), and positive predictive value (77.8% compared to 66.7% and 55.0%, respectively) in detecting individual LNM + . These results suggest that the 3D Resnet model can be valuable for accurately identifying LNM + in head and neck cancer patients. A prospective trial is needed to evaluate further the role of the 3D Resnet model in determining LNM + in head and neck cancer patients and its impact on treatment strategies and patient outcomes.

Comparison of microvascular flow imaging and contrast-enhanced ultrasound for blood flow analysis of cervical lymph node lesions

OBJECTIVE

To compare the diagnostic value of microvascular flow imaging (MVFI) with that of contrast-enhanced ultrasound (CEUS) for the analysis of blood flow in benign and malignant cervical lymph nodes.

MATERIAL AND METHODS

As a prospective study, 95 cervical enlarged lymph nodes (43 benign and 52 malignant) were observed in 95 patients using conventional ultrasonography (including gray and Color Doppler Flow Imaging), CEUS, and MVFI. Two researchers evaluated vascular parameters of MVFI (vascular distribution, internal vascular features, vascular index) and CEUS (enhancement mode, enhancement type) and compared the diagnostic effects of MVFI and CEUS.All results were compared with pathological findings.

RESULTS

There were significant differences in the vascular distribution and internal vascular features of benign and malignant lymph nodes on MVFI (P < 0.05). The vascular distribution of benign lymph nodes was mainly of the central and avascular types, the internal blood vessels were mostly normal, the vascular distribution of malignant lymph nodes was mainly mixed, the internal vessels were mainly tortuous and displaced. The optimal cut-off value of the benign and malignant lymph node vascular index (VI) was 15.55%, and the area under the receiver operating characteristic curve (AUC) of the VI was 0.876. There were also significant differences in the enhancement mode and types of benign and malignant lymph nodes in CEUS (P < 0.05). The benign lymph nodes showed centrifugal perfusion, and the enhancement types were mostly type I and type II. Most malignant lymph nodes showed centripetal or mixed perfusion, and the enhancement types were usually type III and type IV. The accuracy, sensitivity, and specificity of CEUS in the diagnosis of lymph node lesions were 84.2%, 84.6% and 83.7%, respectively, and the AUC was 0.845. The accuracy, sensitivity, and specificity of MVFI in the diagnosis of lymph node lesions were 85.3%, 84.6%, and 86.0%, respectively, and the AUC was 0.886.

CONCLUSION

Both CEUS and MVFI are valuable in differentiating benign and malignant lesions of lymph nodes and have a similar diagnostic performance; however, MVFI is less invasive and simpler than CEUS. Therefore it is preferred for auxiliary examination of enlarged lymph nodes that are difficult to diagnose by conventional ultrasound.

Chest PET/MRI in Solid Cancers: Comparing the Diagnostic Performance of a Free-Breathing 3D-T1-GRE Stack-of-Stars Volume Interpolated Breath-Hold Examination (StarVIBE) Acquisition With That of a 3D-T1-GRE Volume Interpolated Breath-Hold Examination (VIBE) for Chest Staging During Whole-Body PET/MRI

BACKGROUND

Whole-body positron emission tomography/magnetic resonance imaging (WB-PET/MRI) is increasingly used in oncology. However, chest staging remains challenging.

PURPOSE

To compare the diagnostic performance of a free-breathing 3D-T1-GRE stack-of-stars volume interpolated breath-hold examination (StarVIBE) with that of a 3D-T1-GRE volume interpolated breath-hold examination (VIBE) during WB-PET/MRI for chest staging.

STUDY TYPE

Retrospective, cohort study.

POPULATION

One hundred and twenty-three patients were referred for initial staging of solid cancer, 46 of whom had pulmonary nodules and 14 had pulmonary metastasis.

FIELD STRENGTH/SEQUENCE

Free-breathing 3D-T1-GRE stack-of-stars (StarVIBE) and Cartesian 3D-T1-GRE VIBE at 3.0 T.

ASSESSMENT

Image quality was assessed using a 4-point scale and using the signal-to-noise ratio (SNR) of lung parenchyma and contrast-to-noise ratio (CNR) of pulmonary nodules. Diagnostic performances of both sequences were determined by three independent radiologists for detection of pulmonary nodules, lymph node involvement, and bone metastases using chest CT, pathology, and follow-up as reference standards.

STATISTICAL TESTS

Paired Student's t-test; chi-squared; Fisher's exact test. A P value <0.05 was considered statistically significant.

RESULTS

StarVIBE quality was judged as better in 34% of cases and at least equivalent to VIBE in 89% of cases, with significantly higher quality scores (4 [4-4] vs. 3 [3-4], respectively). SNR and CNR values were significantly higher with StarVIBE (8 ± 1.3 and 9.7 ± 4.6, respectively) than with VIBE (1.8 ± 0.2 and 5.5 ± 3.3, respectively). Compared to VIBE, StarVIBE showed significantly higher sensitivity (73% [95% CI 62-82] vs. 44% [95% CI 33-55], respectively) and specificity (95% [95% CI 88-99] vs. 67% [95% CI 56-77]) for pulmonary nodules detection and significantly higher sensitivity (100% [95% CI 89-100] vs. 67% [95% CI 48-82], respectively) for detection of lymph node involvement. Sensitivities for bone metastases detection were not significantly different (100% [95% CI 88-100] vs. 82% [95% CI 63-94], P = 0.054).

DATA CONCLUSION

Owing to improved SNR and CNR and spatial resolution, a free-breathing 3D stack-of-stars T1-GRE sequence improves chest staging in comparison with standard 3D-T1-GRE VIBE and may be integrated in WB-PET/MRI acquisitions for initial staging of solid cancer.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Magnetic resonance imaging (MRI) radiomics of papillary thyroid cancer (PTC): a comparison of predictive performance of multiple classifiers modeling to identify cervical lymph node metastases before surgery

PURPOSE

To compare predictive efficiency of multiple classifiers modeling and establish a combined magnetic resonance imaging (MRI) radiomics model for identifying lymph node (LN) metastases of papillary thyroid cancer (PTC) preoperatively.

MATERIALS AND METHODS

A retrospective analysis based on the preoperative MRI scans of 109 PTC patients including 77 patients with LN metastases and 32 patients without metastases was conducted, and we divided enroll cases into trained group and validation group. Radiomics signatures were selected from fat-suppressed T2-weighted MRI images, and the optimal characteristics were confirmed by spearman correlation test, hypothesis testing and random forest methods, and then, eight predictive models were constructed by eight classifiers. The receiver operating characteristic (ROC) curves analysis were performed to demonstrate the effectiveness of the models.

RESULTS

The area under the curve (AUC) of ROC based on MRI texture diagnosed LN status by naked eye was 0.739 (sensitivity = 0.571, specificity = 0.906). Based on the 5 optimal signatures, the best AUC of MRI radiomics model by logistics regression classifier had a considerable prediction performance with AUCs 0.805 in trained group and 0.760 in validation group, respectively, and a combination of best radiomics model with visual diagnosis of MRI texture had a high AUC as 0.969 (sensitivity = 0.938, specificity = 1.000), suggesting combined model had a preferable diagnostic efficiency in evaluating LN metastases of PTC.

CONCLUSION

Our combined radiomics model with visual diagnosis could be a potentially effective strategy to preoperatively predict LN metastases in PTC patients before clinical intervention.

Computed tomography texture features can discriminate benign from malignant lymphadenopathy in pediatric patients: a preliminary study

BACKGROUND

Differentiation of benign from malignant lymphadenopathy remains challenging in pediatric radiology. Textural analysis (TA) quantitates heterogeneity of tissue signal intensities and has been applied to analysis of CT images.

OBJECTIVE

The purpose of this study was to establish whether CT textural analysis of enlarged lymph nodes visualized on pediatric CT can distinguish benign from malignant lymphadenopathy.

MATERIALS AND METHODS

We retrospectively identified enlarged lymph nodes measuring 10-20 mm on contrast-enhanced CTs of patients age 18 years and younger that had been categorized as benign or malignant based on the known diagnoses. We placed regions of interest (ROIs) over lymph nodes of interest and performed textural analysis with and without feature size filtration. We then calculated test performance characteristics for TA features, along with multivariate logistic regression modeling using Akaike Information Criterion (AIC) minimization, to determine the optimal thresholds for distinguishing benign from malignant lymphadenopathy.

RESULTS

We identified 34 enlarged malignant nodes and 29 benign nodes from 63 patients within the 10- to 20-mm size range. Filtered image TA exhibited 82.4% sensitivity, 86.2% specificity and 84.1% accuracy for detecting malignant lymph nodes using mean and entropy parameters, whereas unfiltered TA exhibited 88.2% sensitivity, 72.4% specificity and 81.0% accuracy using mean and mean value of positive pixels parameters.

CONCLUSION

This preliminary study demonstrates that the use of TA features improves the utility of pediatric CT to distinguish benign from malignant lymphadenopathy. The addition of TA to pediatric CT protocols has great potential to aid the characterization of indeterminate lymph nodes. If definitive differentiation between benign and malignant lymphadenopathy is possible by TA, it has the potential to reduce the need for follow-up imaging and tissue sampling, with reduced associated radiation exposure. However future studies are needed to confirm the clinical applicability of TA in distinguishing benign from malignant lymphadenopathy.

Dual-Energy CT-Derived Iodine Content and Spectral Attenuation Analysis of Metastatic Versus Nonmetastatic Lymph Nodes in Squamous Cell Carcinoma of the Oropharynx

The presence of a single nodal metastasis has significant prognostic and treatment implications for patients with head and neck cancer. This study aims to investigate whether dual-energy computed tomography (DECT)-derived iodine content and spectral attenuation curve analysis can improve detection of nodal metastasis in oropharyngeal carcinoma. Eight patients with newly diagnosed oropharyngeal squamous cell carcinoma and pathologically proven nodal metastatic disease (n = 13 metastatic nodes; n = 16 nonmetastatic nodes) who underwent contrast-enhanced DECT of the neck were retrospectively evaluated. DECT-derived iodine content (mg/mL) and monoenergetic attenuation values at 40 keV and 100 keV were obtained via circular regions of interest within metastatic and nonmetastatic cervical lymph nodes. Iodine content was significantly lower in metastatic nodes (0.96 ± 0.28 mg/mL) than in nonmetastatic nodes (1.65 ± 0.38 mg/mL; P = .002). Iodine spectral attenuation slope was significantly lower in metastatic nodes (1.33 ± 0.49 mg/mL) than in nonmetastatic nodes (1.91 ± 0.64 mg/mL; P = .015). A nodal iodine threshold of ≤1.3 mg/mL showed a sensitivity of 84.6% and a specificity of 75.0%, with an area under the curve of 0.839, P < .0001. At a threshold value of ≤1.95 for nodal spectral attenuation slope, an optimized specificity of 92.3% and specificity of 50.0% was achieved, with an area under the curve of 0.68 (P = .049). DECT-derived quantitative iodine data and spectral attenuation curves may improve the diagnostic accuracy of computed tomography for nodal metastasis in patients with squamous cell carcinoma of the oropharynx.

Muscular invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge is associated with cervical lymph node metastasis

Objectives

To assess the association between muscle invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis on the basis of preoperative magnetic resonance imaging (MRI).

Materials and Methods

Twenty-six patients with oral squamous cell carcinoma of the posterior mandibular alveolar ridge were evaluated by MRI. The associations between cervical lymph node metastasis and independent factors evaluated by MRI were analyzed. Overall survival was also analyzed in this manner. Representative biopsy specimens were stained with anti-podoplanin and anti-CD34 antibodies.

Results

Mylohyoid muscle invasion was associated with cervical lymph node metastasis. A combinational factor of mylohyoid and/or buccinator muscle invasion was also associated with cervical lymph node metastasis. Cervical lymph node metastasis and masticator space invasion had a negative effect on overall survival. No lymphatic vessels were identified near the tumor invasion front within the mandible. In contrast, lymphatic vessels were identified near the front of tumor invasion in the muscles.

Conclusion

This study demonstrates an association between muscular invasion by oral squamous cell carcinoma of the posterior mandibular alveolar ridge and cervical lymph node metastasis.

Clinical outcome of surgical treatment of T1-2 N0 squamous cell carcinoma of oral tongue with observation for the neck: Analysis of 176 cases

OBJECTIVE

To analyze various demographic, clinical, and histopathologic factors in T1-2 N0 squamous cell carcinoma (SCC) of the oral tongue to define a high-risk group for regional recurrence that will benefit from elective neck dissection.

MATERIALS AND METHODS

Retrospective outcome analysis of a patient cohort without palpable or ultrasound (USG) detectable nodal metastases undergoing per oral wide glossectomy for T1-2 N0 SCC of oral tongue. Patients were followed up using palpation and serial USG neck and fine-needle aspiration cytology.

RESULTS

Of the 176 patients, 69 (39%) showed recurrence during follow-up. Fifty-eight cases developed regional neck node metastases, i.e., overall regional node recurrence rate of 33%. Fifty-three (91%) with regional neck node metastases were salvaged successfully with further treatment. In 110 cases with tumor thickness more than 5 mm, 39% cases developed regional neck node metastases. This association was significant with P = 0.0402. Among 44 cases with perineural invasion, 54% developed regional neck node metastases. Similarly in 39 cases with lymphovascular invasion, 61% developed regional neck node metastases. Association of both of these parameters with the development of regional neck node metastases was significant.

CONCLUSION

We recommend prophylactic selective neck dissection in early stage SCC of oral tongue, especially with depth of invasion more than 5 mm, perineural and lymphovascular invasion.

Poor Correlation of Histologic Parameters Between Biopsy and Resection Specimen in Early Stage Oral Squamous Cell Carcinoma

OBJECTIVES

Infiltration depth, perineural growth (PG), vascular invasive growth (VG), and infiltrative growth (IG) are associated with regional metastases in oral squamous cell carcinomas (OSCCs). Preoperative knowledge of these parameters could facilitate the treatment planning of the neck. The aim of this study was to evaluate if the biopsy specimen correlates with the resection specimen.

METHODS

In total, 149 patients with a pT1-2cN0 OSCC were included. Biopsy thickness and tumor thickness were analyzed. Occurrence of PG, VG, and IG was determined on biopsy and resection specimens and correlated with the N status and survival. Sensitivity, specificity, positive and negative predictive value, and diagnostic gain of the biopsy specimen were calculated.

RESULTS

N+ patients showed PG, VG, and IG significantly more often in the resection specimen compared with N- patients (P = .02, P = .001, and P = .001, respectively). Histologic parameters in the biopsy specimens did not correlate with N status or survival. The positive diagnostic gain for biopsy specimens with PG, VG, and IG was 57%, 40%, and 19%, respectively. The negative diagnostic gain was 2%, 0%, and 22%, respectively.

CONCLUSIONS

Histologic parameters in biopsy specimens do not represent the resection specimen. Determination of histologic parameters in routinely taken biopsy specimens of OSCC is not helpful in deciding whether to treat the neck.

Ultrasound-guided fine needle aspiration cytology in the assessment of cervical metastasis in patients undergoing elective neck dissection

BACKGROUND

In head and neck cancer patients, diagnosis of metastatic cervical adenopathy is essential for treatment planning and prognosis assessment. Treatment of patients with head and neck cancer with clinically negative cervical lymph node (N0) remains controversial. While routine neck treatment would result in overtreatment in many patients, observation may delay the diagnosis and decrease the patients' survival.

OBJECTIVES

To gain insights into the unclear questions regarding the value of diagnostic modalities in patients with N0 neck, this study was designed to compare the diagnostic efficacy of palpation, ultrasonography (US) and ultrasound-guided fine needle aspiration (USGFNA) in detecting cervical lymph node metastasis.

PATIENTS AND METHODS

Forty-two patients with head and neck cancer who underwent US and USGFNA prior to elective neck dissection were studied. Histopathologic findings of the neck specimens were compared with each diagnostic technique.

RESULTS

Of the 53 neck dissection specimens, histopathology showed metastases in 16 cases. The overall accuracy of USGFNA, US and palpation was 96%, 68% and 70%, respectively. The specificity of USGFNA was superior to palpation and US alone. USGFNA had the highest sensitivity, predictive value and accuracy in detecting cervical metastases compared with other performed tests.

CONCLUSIONS

In our study, USGFNA was superior to palpation and US in detecting metastasis in clinically negative necks. This method can be recommended as a diagnostic tool in preoperative assessment of patients without palpable metastasis, but further investigations are needed before this modality could be considered as an alternative to elective neck dissection.

Spectral CT imaging of laryngeal and hypopharyngeal squamous cell carcinoma: evaluation of image quality and status of lymph nodes

PURPOSE

The purpose of this study was to evaluate image quality and status of lymph nodes in laryngeal and hypopharyngeal squamous cell carcinoma (SCC) patients using spectral CT imaging.

MATERIALS AND METHODS

Thirty-eight patients with laryngeal and hypopharyngeal SCCs were scanned with spectral CT mode in venous phase. The conventional 140-kVp polychromatic images and one hundred and one sets of monochromatic images were generated ranging from 40 keV to 140 keV. The mean optimal keV was calculated on the monochromatic images. The image quality of the mean optimal keV monochromatic images and polychromatic images was compared with two different methods including a quantitative analysis method and a qualitative analysis method. The HU curve slope (λHU) in the target lymph nodes and the primary lesion was calculated respectively. The ratio of λHU was studied between metastatic and non-metastatic lymph nodes group.

RESULTS

A total of 38 primary lesions were included. The mean optimal keV was obtained at 55 ± 1.77 keV on the monochromatic images. The image quality evaluated by two different methods including a quantitative analysis method and a qualitative analysis method was obviously increased on monochromatic images than polychromatic images (p<0.05). The ratio of λHU between metastatic and non-metastatic lymph nodes was significantly different in the venous phase images (p<0.05).

CONCLUSION

The monochromatic images obtained with spectral CT can be used to improve the image quality of laryngeal and hypopharyngeal SCC and the N-staging accuracy. The quantitative ratio of λHU may be helpful for differentiating between metastatic and non-metastatic cervical lymph nodes.

Elastography: the next step

In the past few decades, various tools have emerged that claim to enhance detection of oral cancer. The most important prognostic factor in patients with oral cancer is lymph node status: the presence of nodal spread decreases the 5-year survival rate by approximately 50%. Differentiation between reactive and metastatic lymphadenopathy is thus vital, and one differentiating criterion is hardness (elasticity) of the lymph node. The purpose of this review is to highlight a promising new ultrasound technique, known as elastography, which measures the characteristics of tissue compliance. The principles underlying elastography are that tissue compression produces strain (displacement) within the tissue - which is lower in harder tissues than in softer tissues - and that malignant tissues are generally harder than normal surrounding tissue. Therefore, elastography might yield clinical information useful in diagnosing cervical metastasis and improving prognosis in oral cancer. It has long been used for cancers of the breast, pancreas, and thyroid, and its use in cervical lymphadenopathy is now being explored, which could lead to great advancements in the diagnosis and prognosis of oral cancer.

Histologic diagnoses in persistently swollen cervical lymph nodes

BACKGROUND

Biopsy and histological examination of persistently enlarged cervical lymph nodes represent a major health care issue and have high impact on further clinical therapy. Tertiary health centers are faced with an increased demand for diagnostic workup to rule out malignancy. We performed a retrospective study from January 2000 to June 2008 to identify patients referred to us for diagnostic biopsy and to document the histopathological result.

METHODS

Patients with a diagnostic biopsy, but neither clinical signs of head and neck cancer nor other malignancies, were identified within the records. Patient characteristics and histopathological diagnosis were retrieved.

RESULTS

Three hundred twenty-six patients were identified (146 women, and 180 men). One hundred twenty-three patients (38%; 44 women, and 79 men) had a malignancy: 61 with metastatic disease and 62 with malignant lymphoma; the youngest was 15 years old and the oldest was 92 years old.

CONCLUSION

Persistently swollen cervical lymph nodes should trigger a thorough clinical examination and prompt biopsy for histopathological workup.

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.