Staging of cervical lymph nodes in oral squamous cell carcinoma: adding ultrasound in clinically lymph node negative patients may improve diagnostic work-up

Imaging and Pathology Concordance in Head and Neck Cancer: Retrospective Analysis

BACKGROUND

Lymph node metastasis critically impacts prognosis in head and neck malignancies. Preoperative imaging (CT/MRI) is vital for assessment but often yields false results. This study examines the concordance between preoperative imaging and postoperative pathology and identifies factors influencing imaging accuracy.

METHODS

A retrospective cohort study from 2014 to 2023 included patients with head and neck malignancies. Clinical and radiological data were analyzed, and the random forest algorithm was utilized for indeterminate cases.

RESULTS

Analyzing 1129 records, 26.1% had indeterminate imaging. Imaging accuracy for definitive findings was 72.8%, sensitivity 57.2%, and specificity 86.0%. Logistic regression highlighted alcohol, T, and clinical stage as accuracy influencers. The indeterminate group showed a link between multiple enlarged lymph nodes and positivity. A nomogram achieved 67.5% accuracy. The random forest model, focusing on lymph node diameter, stage, and T classification, improved accuracy to 75.5% over logistic regression.

CONCLUSION

Our study shows moderate imaging-pathology concordance. Key predictors like lymph node size suggest refining criteria with machine learning could enhance head and neck cancer diagnosis. These results could guide more accurate preoperative imaging assessments, leading to better surgical planning and patient outcomes. Subsequent exploration of adjusting lymph node size thresholds or integrating novel imaging technologies would be useful.

Molecular Markers of Occult Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma (HNSCC) Patients

The accurate diagnosis of regional lymph node metastasis is critical for guiding treatment decisions in head and neck cancer patients. Despite advances in imaging techniques, detecting nodal metastasis using radiology remains challenging, leading to potential undertreatment or overtreatment. This review aims to identify molecular markers associated with occult metastasis in head and neck squamous cell carcinoma (HNSCC) patients. We divided the results by subsite for markers: lymph node analysis (microRNAs, myosin-5a (MYO5A), ring finger protein 145 (RNF145), F-box only protein 32 (FBXO32), CTONG2002744, cytokeratin 14 (CK14), eukaryotic initiation factor 4E (eIF4E), desmoglein-3 (DSG3), microsatellite D9S171, squamous cell carcinoma antigen, cytokeratin, tumor budding score, human papillomavirus-DNA (HPV-DNA), tumor infiltrating lymphocytes, sentinel lymph node analysis techniques, single fiber reflectance spectroscopy, radiological techniques), tumor tissue analysis (activin A, carcinoma-associated fibroblasts, cyclins, β-catenin, histopathology, genetic amplifications, DNA methylation, ecotropic viral integration site 1, CC-chemokine receptor 7, melanoma associated-A antigens, vascular endothelial growth factor-C (VEGF-C), panitumumab, epidermal growth factor receptor (EGFR), cornulin, total protein analysis, CD133, NANOG homeobox, neurogenic locus notch homolog protein 1 (NOTCH1), metastasis-associated protein 1, 14-3-3-zeta, E-cadherin, focal adhesion kinase, p-epithelial-mesenchymal transition (EMT), small proline rich protein 1B (SPRR1B), transcription factor NKX3-1, DNA copy number aberrations, microfibril-associated protein 5 (MFAP5), troponin C1, slow skeletal and cardiac type (TNNC1), matrix Gla protein (MGP), fibroblast growth factor binding protein 1 (FBFBP1), F-box protein 32 (FBXO32), fatty acid binding protein 5, B cell-specific Moloney murine leukemia virus integration site 1, podoplanin, p53, Bcl-2, epidermal growth factor receptor (EGFR), Ki67, cyclin D1, cox-2, semaphorin-3F, neuropilin-2, histologic features, cellular dissociation grade, prospero homeobox protein 1, radiologic features, Ki-67, poly (ADP-ribose) polymerase (PARP), Bcl-2 associated agonist of cell death (BAD), caspase-9, vascular endothelial growth factor A (VEGF-A), HPV, p16, methylation status of long interspersed element 1 (LINE-1) and Alu elements, mesenchymal-epithelial transition (MET), gene expression analyses, molecular subtypes) and blood markers (standard blood analysis indexes and ratios, circulating tumor cells, HPV-DNA, CD-31, bone marrow analysis). Several promising markers were identified, including miR-205, desmoglein 3 (DSG3), pan-cytokeratin (CK) AE1/AE3, HPV-16, activin-A, cyclin D1, E-cadherin, and neural progenitor lineage (NPL) that demonstrated effectiveness across multiple studies. Future research should focus on exploring combination scoring systems to improve diagnostic precision and optimize treatment selection in HNSCC patients.

Comparing the Efficacy of CT, MRI, PET-CT, and US in the Detection of Cervical Lymph Node Metastases in Head and Neck Squamous Cell Carcinoma with Clinically Negative Neck Lymph Node: A Systematic Review and Meta-Analysis

Background: Traditional imaging techniques have limited efficacy in detecting occult cervical lymph node (LN) metastases in head and neck squamous cell carcinoma (HNSCC). Positron emission tomography/computed tomography (PET-CT) has demonstrated potential for assessing HNSCC, but the literature on its efficacy for detecting cervical LN metastases is scarce and exhibits varied outcomes, hindering comparisons. Aim: To compare the efficacy of CT, MRI, PET-CT, and US for detecting LN metastasis in HNSCC with clinically negative neck lymph nodes. Methods: A systematic search was performed using Web of Science, PubMed, Scopus, Embase, and Cochrane databases. Studies comparing CT, MRI, PET-CT, or US to detect cervical metastases in HNSCC were identified. The quality of the studies was assessed using the QUADAS-2 instrument. The positive likelihood ratios (+LR) and negative likelihood ratios (-LR), sensitivity (SEN), specificity (SPE), and diagnostic odds ratio (DOR), with 95% confidence intervals (C.I.), were calculated. Analysis was stratified according to lymph node and patient basis. Results: Fifty-seven studies yielded 3791 patients. At the patient level, PET-CT exhibited the highest diagnostic performance, with a SEN of 74.5% (95% C.I.: 65.4-81.8%) and SPE of 83.6% (95% C.I.: 77.2-88.5%). PET-CT also demonstrated the highest +LR of 4.303 (95% C.I.: 3.082-6.008) and the lowest -LR of 0.249 (95% C.I.: 0.168-0.370), resulting in the highest DOR of 15.487 (95% C.I.: 8.973-26.730). In the evaluation of diagnostic parameters for various imaging modalities on node-based analysis results, MRI exhibited the highest SEN at 77.4%, and PET demonstrated the highest SPE at 96.6% (95% C.I.: 94.4-98%). PET-CT achieved the highest DOR at 24.353 (95% C.I.: 10.949-54.166). Conclusions: PET-CT outperformed other imaging modalities across the majority of studied metrics concerning LN metastasis detection in HNSCC.

Risk stratification of submandibular salivary gland involvement in oral squamous cell carcinoma based on histopathological parameters: A 15-year retrospective study

Objective

Squamous cell carcinoma (SCC) represents about 90% of all oral malignancies. The study aimed to assess the involvement of the submandibular salivary gland (SMG) in oral SCC (OSCC) patients and the need for SMG excision.

Materials and Methods

Demographics, clinical information and staging of the 210 patients undergoing surgery for OSCC were obtained from the department records. The histopathological slides were retrospectively reviewed. The nodal status was also verified with the histopathology reports. Frequency distribution, Chi-square association, ordinal logistic regression analysis and Kaplan-Meier analysis were performed.

Results

SMG was excised in 171 patients. Five patients had SMG involvement. Buccal mucosa (BM) and gingivobuccal sulcus had a greater risk of level IB metastases (P < 0.01). Pattern 3 and pattern 4 of invasion had a higher risk of level IB metastases (P = 0.04). Depth of invasion (DOI) >4 mm was associated with level IB lymph node (LN) involvement (P = 0.0001). DOI >4 mm to 8 mm had 3.7 times the risk and a DOI >8 mm to 12 mm had 5 times the risk of level IB metastases. Pattern of invasion (POI), tumour budding and DOI >4 mm were significant prognosticators for patient survival.

Conclusion

Histologically, patients may be categorised as 'high risk': those with an increased risk of level IB LN involvement and 'low risk': those at low risk for level IB involvement with the help of POI, tumour budding and DOI as risk factors. In low-risk patients, SMG may be spared and the level IB LNs are dissected. High-risk patients may be chosen as candidates for SMG transfer or excision based on the extent of LN involvement.

Efficacy of texture analysis of ultrasonographic images in the differentiation of metastatic and non-metastatic cervical lymph nodes in patients with squamous cell carcinoma of the tongue

OBJECTIVE

We investigated the efficacy of using texture analysis of ultrasonographic images of the cervical lymph nodes of patients with squamous cell carcinoma of the tongue to differentiate between metastatic and non-metastatic lymph nodes.

STUDY DESIGN

We analyzed 32 metastatic and 28 non-metastatic lymph nodes diagnosed by histopathologic examination on presurgical US images. Using the LIFEx texture analysis program, we extracted 36 texture features from the images and calculated the statistical significance of differences in texture features between metastatic and non-metastatic lymph nodes using the t test. To assess the diagnostic ability of the significantly different texture features to discriminate between metastatic and non-metastatic nodes, we performed receiver operating characteristic curve analysis and calculated the area under the curve. We set the cutoff points that maximized the sensitivity and specificity for each curve according to the Youden J statistic.

RESULTS

We found that 20 texture features significantly differed between metastatic and non-metastatic lymph nodes. Among them, only the gray-level run length matrix feature of run length non-uniformity and the gray-level zone length matrix features of gray-level non-uniformity and zone length non-uniformity showed an excellent ability to discriminate between metastatic and non-metastatic lymph nodes as indicated by the area under the curve and the sum of sensitivity and specificity.

CONCLUSIONS

Analysis of the texture features of run length non-uniformity, gray-level non-uniformity, and zone length non-uniformity values allows for differentiation between metastatic and non-metastatic lymph nodes, with the use of gray-level non-uniformity appearing to be the best means of predicting metastatic lymph nodes.

The Applications and Potential Developments of Ultrasound in Oral Cancer Management

Oral cancer is endemic and causes a great burden in Southern Asia. It is preferably treated by surgery with/without adjuvant radiotherapy (RT) or chemoradiation therapy, depending on the stage of the disease. Close or positive resection margin and cervical lymph node (LN) metastasis are important prognostic factors that have been presented to be related to undesirable locoregional recurrence and poor survival. Ultrasound (US) is a simple, noninvasive, time-saving, and inexpensive diagnostic modality. It can depict soft tissues very clearly without the risk of radiation exposure. Additionally, it is real-time and continuous image is demonstrated during the exam. Furthermore, the clinician can perform US-guided fine needle aspiration (FNA) or core needle biopsy (CNB) at the same time. US with/without US-guided FNA/CNB is reported to be of value in determining tumor thickness (TT), depth of invasion (DOI), and cervical LN metastasis, and in aiding the staging of oral cancer. DOI has a relevant prognostic value as reported in the eighth edition of the American Joint Committee on Cancer staging of oral cancer. In the present review, we describe the clinical applications of US in oral cancer management in different phases and potential applications in the future. In the pretreatment and surgical phase, US can be used to evaluate TT/DOI and surgical margins of oral cancer in vivo and ex vivo. The prediction of a malignant cervical LN (nodal metastasis) by the US-based prediction model can guide the necessity of FNA/CNB and elective neck dissection in clinical early-stage oral cancer. In the posttreatment surveillance phase, US with/without US-guided FNA or CNB is helpful in the detection of nodal persistence or LN recurrence, and can assess the possibility and extent of carotid artery stenosis after irradiation therapy. Both US elastography and US swallowing assessment are potentially helpful to the management of oral cancer.

Unilateral versus bilateral nodal irradiation: Current evidence in the treatment of squamous cell carcinoma of the head and neck

Cancers of the head and neck region often present with nodal involvement. There is a long-standing convention within the community of head and neck radiation oncology to irradiate both sides of the neck electively in almost all cases to include both macroscopic and microscopic disease extension (so called elective nodal volume). International guidelines for the selection and delineation of the elective lymph nodes were published in the early 2000s and were updated recently. However, diagnostic imaging techniques have improved the accuracy and reliability of nodal staging and as a result, small metastases that used to remain undetected and were thus in the past included in the elective nodal volume, will now be included in high-dose volumes. Furthermore, the elective nodal areas are situated close to the parotid glands, the submandibular glands and the swallowing muscles. Therefore, irradiation of a smaller, more selected volume of the elective nodes could reduce treatment-related toxicity. Several researchers consider the current bilateral elective neck irradiation strategies an overtreatment and show growing interest in a unilateral nodal irradiation in selected patients. The aim of this article is to give an overview of the current evidence about the indications and benefits of unilateral nodal irradiation and the use of SPECT/CT-guided nodal irradiation in squamous cell carcinomas of the head and neck.

[18F]FDG PET/MRI versus contrast-enhanced MRI in detecting regional HNSCC metastases

OBJECTIVE

To compare the accuracy of contrast-enhanced MRI using established dimensional and morphological criteria versus integrated [¹⁸F]FDG PET/MRI in identifying regional lymph node metastases in patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC). For this purpose, we compare MRI and PET/MRI using the histopathological findings in dissected lymph nodes as the gold standard.

METHODS

We retrospectively reviewed 26 patients with histologically proven HNSCC who underwent gadolinium-enhanced [¹⁸F]FDG PET/MRI as part of their staging. All neck lymph nodes were classified on MRI using dimensional and/or morphological criteria. Then, they were jointly assessed by a nuclear medicine physician and a radiologist using integrated [¹⁸F]PET/MR images. ROC curves were obtained to compare the techniques. Lymph node histopathology was considered as the reference standard.

RESULTS

Out of 865 lymph nodes, 35 were malignant at histopathology (3 with micro-metastases). Sensitivity and specificity were 48.6% and 99.5% for MRI using dimensional criteria; 60.0% and 99.6% for MRI using morphological criteria; 60.0% and 99.4% for MRI using both; and 74.3% and 97.6% for PET using MR as anatomic localization. The area under the ROC curve was higher for PET and MRI localization (0.859) than for MRI using dimensional (0.740; p < 0.05), or morphological (0.798; p < 0.05), or both criteria (0.797; p < 0.05). PET/MR using a PET SUVmax cutoff of 5.7 combined with MRI using dimensional and/or morphological criteria reached high values for accuracy (98.2%), NPV (98.2%), and PPV (95.2%).

CONCLUSIONS

Compared with traditional contrast-enhanced MRI or PET alone, integrated PET/MRI could improve diagnostic accuracy in detecting metastatic lymph nodes in patients with HNSCC.

Benign and Malignant Lesions of Jaw

Benign and malignant neoplasm of oral cavity is usually presented as swellings or ulcerations of affected tissue. The lesions are broadly categorized as potentially malignant disorders, benign and malignant neoplasm of epithelial and connective tissue origin for the convenience of learning. Neoplasm of oral cavity has a significantly lower incidence. Because of uncommon occurrence of oral neoplasm, retention of diagnostic skills is a challenging task. However, comprehensive understanding on clinical and pathologic details will help in correlating and presenting complaint and assisting in formulation of possible diagnosis. The key for successful therapeutic management depends on achieving right and timely diagnosis.

[Capabilities of contrast-enhanced ultrasound for preoperative assessment of regional lymphatic basin in patients with early oral cavity squamous cell cancer]

This review paper describes the possibilities of visualization of regional lymph nodes using contrast-enhanced ultrasound. Discussed is the experience of contrast-enhanced ultrasound implication for differential diagnosis of regional metastases of squamous cell carcinoma of the oral mucosa. The basics of the technique of contrast-enhanced ultrasound examination of the neck lymphatic basin are described.

Evaluation of the Expression of Matrix Metalloproteinase-1 of Laryngeal Squamous Cell Carcinoma by Ultrasound Molecular Imaging

Purpose: The aims of this study were to evaluate the expression of matrix metalloproteinase-1 (MMP-1) on laryngeal squamous cell carcinoma (LSCC) and improve the early diagnosis rate via ultrasound molecular imaging (USMI).

Methods: The microsized MMP-1-targeted microbubbles (MB_MMP-1) and the control MBs (MB_IgG) based on perfluorocarbon-filled lipid-shelled MBs were constructed and characterized. The in vitro binding experiment was performed with human epidermoid laryngeal cancer cells (HEp-2) and tested the binding efficiency of MB_MMP-1 and MB_IgG. In the in vivo study, the LSCC model was established in 10 mice. The MB_MMP-1 and MB_IgG were randomly injected into tumor-bearing mice via the tail vein at Day 7, Day 12, and Day 17 to dynamically evaluate the differential targeted enhancement (dTE) signals via USMI. Subsequent immunofluorescence analysis was used for confirmation of MMP-1 expression.

Result: The effective adhesion rate of MB_MMP-1 and MB_IgG to HEp-2 was 298.42 ± 16.57 versus 12.38 ± 3.26 bubbles/per field in vitro experiment, which shows a significant difference (P < 0.01). The in vivo ultrasound molecular imaging (USMI) results demonstrated that dTE signal intensity from MB_MMP-1 was significantly higher than that from the MB_IgG at Day 7, Day 12, and Day 17 (Day 7, 41.21 ± 15.00 versus 2.25 ± 0.6 a.u., P < 0.05; Day 12, 124.64 ± 5.19 versus 11.13 ± 1.13 a.u., P < 0. 05; Day 17, 332.01 ± 64.88 versus 42.99 ± 11.9 a.u., P < 0.01). Moreover, immunofluorescence analysis further confirmed the expression of MMP-1 in LSCC with a gradual increase with the tumor growth.

Conclusion: MB_MMP-1 could be a potential probe that can be used in the early diagnosis of LSCC by USMI.

Cell-Free Plasma DNA for Disease Stratification and Prognosis in Head and Neck Cancer

BACKGROUND

Clinicians face many challenges in disease stratification and outcome prediction in head and neck squamous cancer cell (HNSCC) patients. Given the limitations of currently used clinical scoring, repetitive biopsies, and imaging techniques, liquid biopsy approaches may provide valuable additional diagnostic and prognostic information.

METHODS

A noninterventional, single-center observational study was performed with clinical data and plasma samples from HNSCC patients. Cell-free tumor DNA-derived copy number aberrations (CNAs) were determined in 116 patients by low-coverage next-generation sequencing (NGS). Significant CNAs were combined in a genome-wide copy number instability score (CNI), which was evaluated with respect to conventional clinical staging and patient outcome.

RESULTS

Receiver-operating characteristic (ROC) curve analysis comparing the presurgery CNI in patients (n = 103) with that in tumor-free controls (n = 142) yielded an area under the ROC curve of 87.2% (95% CI, 79.4%-93.3%). At a specificity of 95%, the sensitivity to detect tumors varied between 46% (pT1) and 94% (pT4). A CNI above the median (i.e., >72) had a positive predictive value of 90% (95% CI, 79%-96%) for lymph node involvement (LNI), while the negative predictive value was 57% (95% CI, 43%-70%). For a CNI >72, overall survival (OS) was worse (hazard ratio, 4.89; 95% CI, 1.39-17.17; P = 0.01) with 62% and 90% survivors 3 years after surgery for a CNI >72 and ≤72, respectively. In multivariable models, the CNI was a superior predictor of OS compared to established disease features, including LNI.

CONCLUSIONS

The CNI may assist in predicting LNI and prognosis in HNSCC with direct therapeutic implications concerning the need for neck dissection or more aggressive treatment.

Role of Neck Dissection in Clinical T3N0M0 Lesion of Oral Cavity: Changing Trend

INTRODUCTION

Neck dissection is an important part in the management of head and neck malignancies especially in terms of control of nodal metastasis. The study is focused on evaluating the profile of lymph nodes in T₃N₀M₀ lesion of different subsides of oral cavity.

AIM

To evaluate the utility of neck dissection in T₃N₀M₀ stage of carcinomas of the different region of oral cavity.

MATERIALS AND METHODS

Ninety patients aged 20 to 70 years underwent treatment for carcinoma of the oral cavity at our center between 2005 and 2013. Of these, 39 patients were stage T₃N₀M₀ and underwent excision of the primary lesion with neck dissection. The data were collected retrospectively from hospital record library. These patients were evaluated clinically, radiologically and compared with intra operative finding. Addition of radiotherapy was decided on final histopathology.

RESULTS

Out of 39 patients, the site of primary tumour in 21 patients was tongue, in 13 patients was Buccal Mucosa (BM), in 2 patients was lip and in 3 patients was Floor of Mouth (FOM) with tongue. In patients with clinically negative neck nodes, ultrasonography and intra-operative examination revealed the presence of suspicious nodes in 35.9% and 30.7% cases respectively. Occult metastasis in the nodes was identified on histopathological examination in 15 patients (38.5%). A total of 14 patients of carcinoma of tongue and one patient of BM showed positive nodes on histopathology. These patients with positive neck nodes on histopathology, were sent for postoperative radiotherapy. At follow up examination, four patients showed local and distal recurrence and they were managed accordingly. Out of 39 patients, 11 patients of BM, 2 patients of lip, 1 patient of FOM and 6 patients of tongue were disease free in last follow up.

CONCLUSION

Selective neck dissection is an effective therapeutic intervention in patients without clinically involved neck nodes. It can upstage the tumour and additional treatment may be advised. In patients with carcinoma of buccal mucosa and lip, the patients can be kept under regular follow up when biopsy report showed excision with adequate margin and no nodal metastasis.

A new evidence-based risk stratification system for cutaneous squamous cell carcinoma into low, intermediate, and high risk groups with implications for management

Most primary cutaneous squamous cell carcinomas are cured with surgery. A subset, however, may develop local and nodal metastasis that may eventuate in disease-specific; death. This subset has been variably termed high risk. Herein, we review; an emerging body of data on the risks of these outcomes and propose an evidence-based; risk stratification for low-, intermediate-, and high-risk tumors that takes into; account both tumor and patient characteristics. Finally, we discuss a framework for; management of these tumors on the basis of data, when available, and our; recommendations when data are sparse.

Comparative analysis of detecting cervical lymph node metastasis with fine needle aspiration cytology

Objectives:

We correlated the results of cervical lymph node (LN) status by T-tumor size, N-nodal metastasis, M-distant metastasis (TNM) staging, and fine needle aspiration cytology (FNAC) in oral cancer patients to assess the discrepancy index (DI) between nodal metastasis (N) and FNAC results of cervicofacial LNs.

Materials and Methods:

A total of 63 patients (29 females and 34 males) aged from 30 to 85 years were included in our study. Cervical LN status through TNM staging and FNAC results were matched and DI was calculated.

Results:

DI in case of nodal status was 64.10% and 43.47% for TNMN1 and N2, respectively, indicating that tendency for observation of positive result on FNAC increased from N1 to N2.

Conclusion:

Hence, we suggest that relying solely on clinical examination and routine diagnostic tests like FNAC may not be appropriate and additional diagnostic imaging modalities should be considered.

Staging of early lymph node metastases with the sentinel lymph node technique and predictive factors in T1/T2 oral cavity cancer: A retrospective single-center study

BACKGROUND

The purpose of this study was to examine the diagnostic accuracy of detecting lymph node metastases and to identify predictive and prognostic clinicopathological factors in patients with oral squamous cell carcinoma (OSCC) undergoing sentinel lymph node biopsy (SLNB).

METHODS

All patients diagnosed with cT1 to T2N0 OSCC who underwent a diagnostic SLNB between 2007 and 2013 were included.

RESULTS

We identified 253 patients, of whom 27% had a positive sentinel lymph node (SLB). The false-negative rate, sensitivity, and negative predictive value (NPV) were 5%, 88%, and 95%, respectively. Patients with micrometastases as well as macrometastases had a separately, significantly shorter disease-specific survival than patients with pN0 disease. In a logistic regression model, the maximum tumor thickness, perineural invasion, and differentiation grade were independent predictive factors for the presence of metastases.

CONCLUSION

These data support the use of the SLNB technique as an accurate and safe staging tool in patients with OSCC with a cN0 neck. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1033-E1040, 2016.

Sentinel Node Biopsy for the Head and Neck Using Contrast-Enhanced Ultrasonography Combined with Indocyanine Green Fluorescence in Animal Models: A Feasibility Study

Background

Sentinel node navigation surgery is gaining popularity in oral cancer. We assessed application of sentinel lymph node navigation surgery to pharyngeal and laryngeal cancers by evaluating the combination of contrast-enhanced ultrasonography and indocyanine green fluorescence in animal models.

Methods

This was a prospective, nonrandomized, experimental study in rabbit and swine animal models. A mixture of indocyanine green and Sonazoid was used as the tracer. The tracer mixture was injected into the tongue, larynx, or pharynx. The sentinel lymph nodes were identified transcutaneously by infra-red camera and contrast-enhanced ultrasonography. Detection time and extraction time of the sentinel lymph nodes were measured. The safety of the tracer mixture in terms of mucosal reaction was evaluated macroscopically and microscopically.

Results

Sentinel lymph nodes were detected transcutaneously by contrast-enhanced ultrasonography alone. The number of sentinel lymph nodes detected was one or two. Despite observation of contrast enhancement of Sonazoid for at least 90 minutes, the number of sentinel lymph nodes detected did not change. The average extraction time of sentinel lymph nodes was 4.8 minutes. Indocyanine green fluorescence offered visual information during lymph node biopsy. The safety of the tracer was confirmed by absence of laryngeal edema both macro and microscopically.

Conclusions

The combination method of indocyanine green fluorescence and contrast-enhanced ultrasonography for detecting sentinel lymph nodes during surgery for head and neck cancer seems promising, especially for pharyngeal and laryngeal cancer. Further clinical studies to confirm this are warranted.