A study on the correlation of Doppler ultrasound in the diagnosis of cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers: An observational study

Abstract

The objective was to assess the diagnostic efficacy of Doppler ultrasound in detecting cervical lymph nodes in patients diagnosed with laryngeal and hypopharyngeal cancers. Patients undergoing surgery for laryngeal and hypopharyngeal cancers in the Otolaryngology Department from January 2021 to January 2023 were included. Two groups, with equal numbers, underwent ultrasound examination and intensive CT examination in the experimental and control groups, respectively, along with routine cervical lymph node dissection. A resident with over 6 years of clinical experience in the otolaryngology department performed routine bilateral cervical lymph node palpation. Sensitivity, specificity, and validity were compared among different examination methods. The McNemar test assessed specificity and sensitivity between palpation, color Doppler ultrasonography, and enhanced CT, while the Kappa concordance test evaluated the concordance between the 2 examination methods. Data were statistically analyzed using SPSS 23.0. Palpation showed a diagnostic sensitivity (DS) of 52.83% and specificity of 91.11% for all patients with cervical lymph node metastasis. Ultrasonography demonstrated a DS of 77.78% and specificity of 81.82% in patients with cervical lymph node metastasis, while intensive CT had a DS of 75.86% and specificity of 60.00%. Statistical significance (P < .05) was observed in the sensitivity between palpation and ultrasonography, and between palpation and enhanced CT. The specificity between enhanced CT and ultrasonography (P = .021) and between palpation and enhanced CT scan (P = .003) both showed statistical significance (P < .05). Doppler ultrasound yields diagnostic results highly consistent with pathological diagnoses in patients with laryngeal and hypopharyngeal cancers. Utilizing Doppler ultrasound can enhance the accuracy of diagnosing these cancers, aiding physicians in devising more suitable treatment plans for patients.

1. Introduction

Laryngeal and hypopharyngeal cancers, representing prevalent head and neck malignancies, contribute to approximately 33.5% of cases.^[1] Conventional treatment modalities for these cancers encompass surgery, radiotherapy, chemotherapy, and immunotherapy. Within the intricate tissue structure of the head and neck, aside from the acoustic region, abundant lymphatic tissue exists, making smaller primary tumors in these regions highly susceptible to lymph node metastasis (LNM).^[2,3] Consequently, an active exploration of the patterns and methodologies of LNM in the neck becomes imperative to formulate effective treatment strategies and curb extensive LNM.

As a widely employed diagnostic tool in clinical oncology, Doppler ultrasound technology offers a radiation-free, noninvasive, and portable solution. Additionally, color Doppler ultrasound facilitates the observation of internal structure changes and blood flow in lymph nodes.^[4,5] The versatility of color Doppler ultrasound technology is evident in various clinical diagnostic applications.^[6] Alis et al^[7] investigated the efficacy of Superb microangiography and power Doppler ultrasound in diagnosing synovial inflammation of the knee joint in patients with juvenile idiopathic arthritis, with power Doppler ultrasound imaging demonstrating superiority. Ge et al^[8] explored the effectiveness of Doppler ultrasound technology in fetal cardiac structure examinations, revealing its capability to detect fetal heart malformations and provide a reliable foundation for comprehensive understanding of the pregnant individual’s condition and subsequent treatment, thereby enhancing the quality of newborns.

In light of the aforementioned context, we postulate that Doppler ultrasound technology holds significant promise in diagnosing neck lymph nodes in patients with hypopharyngeal cancer. If the diagnostic efficacy of Doppler ultrasound technology proves comparable to or surpasses that of traditional enhanced CT scans and routine lymph node dissection, the diagnostic process using Doppler ultrasound technology could offer a more convenient and safe alternative. Therefore, this study aims to investigate and compare the effectiveness and significance of Doppler ultrasound technology in diagnosing neck lymph nodes in patients with hypopharyngeal cancer, providing valuable insights for devising more tailored treatment plans.

2. Materials and methods

2.1. General information

This research received approval from the Ethics Committee of Zhuzhou Hospital, affiliated with Xiangya School of Medicine. The study focused on patients diagnosed with laryngeal and hypopharyngeal cancers who underwent surgery in our otolaryngology department between January 2021 and January 2023. Comprehensive examinations, including routine assessments, were conducted for all patients, with the collection of both pathological and imaging data from individual cases. The inclusion criteria for patients were: patients capable of providing informed consent; patients with normal mental status, language proficiency, and comprehension; patients experiencing noticeable foreign body sensation in the throat, accompanied by pain and breathing difficulties; pathological examination confirming the diagnosis of laryngeal or hypopharyngeal cancer, and no ongoing relevant treatment; patients able to collaborate with the hospital to complete all ultrasound and intensive CT examinations. Exclusion criteria were: patients with missing diagnostic results; patients unable to provide informed consent; patients with other serious systemic diseases; patients with a history of previous pharyngeal surgery; patients with neurological impairment affecting proper communication. The hospital’s ethics committee granted approval for this research, and both patients and their families provided signed consent forms.

2.2. Research methodology

A resident, possessing over 6 years of clinical experience in our otolaryngology department, conducted routine bilateral cervical lymph node palpation for each participant. To ensure randomization, 98 envelopes were prepared in advance, with 49 allocated to the experimental group and 49 to the control group. These envelopes were then placed in a blinded box.

Before surgery, a random draw from the box was performed for each patient’s inclusion, determining whether they would be assigned to the experimental or control group. Patients in the control group underwent intensive CT examination of the neck and routine cervical lymph node dissection. In contrast, patients in the experimental group underwent bilateral ultrasound examination of the neck along with routine cervical lymph node dissection.

During palpation and all examinations, the size, hardness, and clinical characteristics of the lymph nodes were meticulously recorded. This process ensured a standardized approach to data collection for both groups.

When comparing the relative negative/positive rates of the 2 groups after the pathological diagnosis, the 2 groups were divided into laryngeal cancer patient groups and hypopharyngeal cancer patient groups, respectively. Therefore, in the final negative/positive rate presentation, the experimental group and the control group respectively included 3 categories of negative/positive rate calculation ranges, namely A, B, and C. A. Groups B and C respectively represent all patient groups, laryngeal cancer patient groups, and hypopharyngeal cancer patient groups.

2.3. Related inspection instruments and their use

2.3.1. For color Doppler ultrasound examination

Patients were placed in a supine position with their neck fully exposed, and a PHILIPS IU22 color ultrasound instrument was utilized for diagnosis. The instrument probe operated at a frequency between 8 and 10 MHz. Positioned on the patient’s neck, the probe examined the distribution of lymph nodes in the lateral cervical region. Observations included the length, shape, and cortical status of lymph nodes, with meticulous recording of relevant data.

2.3.2. For lymph node dissection using enhanced CT

Patients were positioned supine with the chin elevated to fully expose the pharynx and maintain a straight neck. Transverse, longitudinal, and oblique views were conducted from the base of the skull to below the superior sternal fossa, employing a transsphenoidal approach. The PHILIPS iCT facilitated the enhanced CT scan with parameters set at 120 kV voltage, 50 kA current, 3 mm layer thickness, 2 mm pitch, and 350 iopidol contrast agent administered intravenously, followed by scanning after 30 seconds. Throughout the scanning process, all enhancement scans were executed, and parallel multiplanar reconstruction was performed for comprehensive evaluation.

2.4. Pathological examination

Following neck lymph node dissection surgery, the excised lymph node tissues undergo zoning and localization. Pathological examination is subsequently conducted to ascertain a precise diagnosis. Pathologists engage in wax immersion, embedding, sectioning, staining, and microscopic examination of the submitted pathological tissues. Diagnosis is then undertaken collaboratively by surgeons and pathologists, each possessing over 5 years of clinical experience in otorhinolaryngology. Notably, patients exhibiting abnormal findings in palpation, ultrasound, or CT were excluded from the analysis.

2.5. Diagnostic indicators

The criteria for determining palpation findings are as follows: Patients presenting with cervical lymph nodes measuring >2 cm or with palpation findings exceeding 1.5 cm on the same side as the primary focus were classified as having positive lymph node metastases. The resident assesses the metastatic status of the lymph nodes by considering factors such as size, shape, and activity.

Positive LNM is determined by the presence of either the loss of lymphatic portal structures or the loss of lymph node dermomyelination. Additionally, patients exhibiting 2 or more of the following 8 phenomena are considered to have positive LNM: short lymph node diameter exceeding 1 cm; lymph node length-to-diameter ratio >2; blurred dermal medullary boundary; eccentric hypertrophy of the cortex; internal lamellar necrosis or punctate necrosis with hypoechogenicity; uneven internal echogenicity; poorly defined borders; peripheral blood flow in the lymph nodes.

Intensive CT scan index: Positive LNM is determined if the patient presents with any 2 of the following 6 phenomena: short diameter of lymph nodes exceeding 1 cm; ratio of long to short diameter >2; aggregation of lymph nodes in the area of the primary focus; encapsulated infiltration; internal presence of sheet necrosis or punctate necrosis with hypoechogenicity; irregular marginal enhancement.

2.6. Statistical data processing methods

Statistical analyses of the data collected in this experiment were conducted utilizing SPSS 23.0. For data conforming to a normal distribution, representation was performed using the mean (x) ± standard deviation (S), and ANOVA was carried out. The cardinality test was employed to analyze the relationship between the rates of the 2 groups. To assess specificity and sensitivity between palpation, color Doppler ultrasonography, and intensive CT examination, the McNemar test was employed. Additionally, the Kappa concordance test was adopted to evaluate the agreement between the different examination methods.

3. Results

3.1. Comparison of general information

Table 1 presents the fundamental information. Mean age, gender, height, weight, tumor TNM stage, and neck lymph node stage were individually compared between the 2 groups. Notably, height, weight, and mean age exhibited a normal distribution. ANOVA was applied and revealed no significant difference in height (P > .05). Furthermore, the comparison of tumor T-stage and cervical lymph node N-stage between the experimental and control groups, conducted through a chi-square test, indicated no significant difference (P > .05).

Table 1.

Comparison of patients’ general information.

Projects	Properties	Control group	Experimental group	$t/{\chi }^2$	P
Number of people	/	49	49	/	/
Average age	Year	61.65 ± 9.32	61.58 ± 10.06	0.936	.732
Height	Cm	166.05 ± 15.62	166.22 ± 16.04	1.156	.095
Body weight	Kg	67.98 ± 16.05	67.59 ± 15.95	1.263	.079
Tumor T-stage	Tis	4	3	0.265	.263
	T1	8	7	0.315	.225
	T2	12	15	0.356	.364
	T3	16	12	0.458	.395
	T4	10	13	0.398	.346
Cervical lymph node N-stage	N0	16	15	0.413	.531
	N1	21	20	0.526	.716
	N2	13	15	0.465	.651

3.2. Analysis of the diagnostic validity of palpation in cervical lymph node metastasis

Table 2 illustrates the concordance analysis results between neck palpation findings and pathology reports in patients diagnosed with laryngeal and hypopharyngeal cancers. The sensitivity of neck palpation for diagnosing LNM was 52.83% (28/53) with a specificity of 91.11% (41/45) across all patients. For patients with laryngeal cancer, the sensitivity was 20.00% (3/15), with a specificity of 96.30% (26/27). Hypopharyngeal cancer patients exhibited a sensitivity of 66.67% (24/36) and a specificity of 80.00% (16/20) in the diagnosis of LNM through palpation.

Table 2.

Palpation findings and pathological findings of cervical lymph nodes.

Diagnostic methods and results		Pathological findings in patients with laryngeal and hypopharyngeal cancers
		Negative	Positive	Total
Palpation findings	Negative	41 (91.11%)	25 (47.17%)	66
	Positive	4 (8.89%)	28 (52.83%)	32
	Total	45	53	98
Positive/negative predictive value		PPV: 87.5%	NPV: 62.1%

Diagnostic methods and results		Pathological findings in patients with laryngeal cancer
		Negative	Positive	Total
Palpation findings	Negative	26 (96.30%)	12 (80.00%)	38
	Positive	1 (3.70%)	3 (20.00%)	4
	Total	27	15	42
Positive/negative predictive value		PPV: 75.00%	NPV: 68.42%

Diagnostic methods and results		Pathological findings in patients with hypopharyngeal cancer
		Negative	Positive	Total
Palpation findings	Negative	16 (80.00%)	12 (33.33%)	28
	Positive	4 (20.00%)	24 (66.67%)	28
	Total	20	36	56
Positive/negative predictive value		PPV: 85.71%	NPV: 57.10%

3.3. Analysis of the diagnostic validity of color Doppler ultrasonography in cervical lymph node metastasis

In color Doppler ultrasonography, Table 3 shows the concordance analysis between ultrasound findings and pathology reports in patients with laryngeal cancer and hypopharyngeal cancer. In Table 3, the diagnostic sensitivity (DS) of ultrasonography was 77.78% (42/54) and the specificity was 81.82% (36/44) in all patients with LNM in the neck. The DS of ultrasonography in LNM in the neck of patients with laryngeal cancer was 77.78% (14/18) and the specificity was 91.67% (22/24). The DS of ultrasonography in LNM in the neck of hypopharyngeal cancer patients was 91.43% (32/35), and the specificity was 61.90% (13/21).

Table 3.

Color Doppler ultrasound findings and pathological findings of the cervical lymph nodes.

Diagnostic methods and results		Pathological findings in patients with laryngeal and hypopharyngeal cancers
		Negative	Positive	Total
Color Doppler ultrasound Inspection results	Negative	36 (81.82%)	12 (22.22%)	48
	Positive	8 (18.18%)	42 (77.78%)	50
	Total	44	54	98
Positive/negative predictive value		PPV: 84.00%	NPV: 75.00%

Diagnostic methods and results		Pathological findings in patients with laryngeal cancer
		Negative	Positive	Total
Color Doppler ultrasound inspection results	Negative	22 (91.67%)	4 (22.22%)	26
	Positive	2 (8.33%)	14 (77.78%)	16
	Total	24	18	42
Positive/Negative Predictive Value		PPV: 87.50%	NPV: 84.61%

Diagnostic methods and results		Pathological findings in patients with hypopharyngeal cancer
		Negative	Positive	Total
Color Doppler ultrasound Inspection results	Negative	13 (61.90%)	3 (8.57%)	16
	Positive	8 (38.10%)	32 (91.43%)	40
	Total	21	35	56
Positive/negative predictive value		PPV: 80.00%	NPV: 81.25%

3.4. Analysis of the diagnostic validity of intensive CT examination in cervical lymph node metastasis

In the intensive CT examination, Table 4 displays the concordance analysis between the intensive CT findings and pathology reports of patients with laryngeal cancer and patients with hypopharyngeal cancer. In Table 4, the DS of intensive CT examination was 75.86% (44/58) and the specificity was 60.00% (24/40) in all patients with LNM in the neck. The DS of intensive CT examination in LNM in the neck of laryngeal cancer patients was 94.74% (18/19), and the specificity was 69.57% (16/23). The DS of intensive CT examination in LNM in the neck of hypopharyngeal cancer patients was 94.12% (32/34), and the specificity was 54.55% (12/22).

Table 4.

Intensive CT findings and pathological findings of cervical lymph nodes.

Diagnostic methods and results		Pathological findings in patients with laryngeal and hypopharyngeal cancers
		Negative	Positive	Total
Intensive CT inspection results	Negative	24 (60.00%)	14 (24.14%)	38
	Positive	16 (40.00%)	44 (75.86%)	60
	Total	40	58	98
Positive/negative predictive value		PPV: 73.33%	NPV: 63.16%

Diagnostic methods and results		Pathological findings in patients with laryngeal cancer
		Negative	Positive	Total
Intensive CT inspection results	Negative	16 (69.57%)	1 (5.26%)	17
	Positive	7 (30.43%)	18 (94.74%)	25
	Total	23	19	42
Positive/negative predictive value		PPV: 72.00%	NPV: 94.12%

Diagnostic methods and results		Pathological findings in patients with hypopharyngeal cancer
		Negative	Positive	Total
Intensive CT Inspection results	Negative	12 (54.55%)	2 (5.88%)	14
	Positive	10 (45.45%)	32 (94.12%)	42
	Total	22	34	56
Positive/negative predictive value		PPV: 76.19%	NPV: 85.71%

Figure 1 shows the results of various indicators for neck palpation, color Doppler ultrasound, and enhanced CT diagnosis of LNM. A. Groups B and C respectively represent all patient groups, laryngeal cancer patient groups, and hypopharyngeal cancer patient groups. As shown in Figure 1, the false positive rates of Groups A, B, and C were 8.89%, 3.70%, and 20.00%, respectively, while the false negative rates were 47.17%, 80.00%, and 33.33%. As shown in Figure 1B, the true positive rates of Groups A, B, and C were 52.83%, 20.00%, and 66.67%, while the true negative rates were 91.11%, 96.30%, and 80.00%. As shown in Figure 1C, the false positive rates of Groups A, B, and C were 18.18%, 8.33%, and 38.10%, while the false negative rates were 22.22%, 22.22%, and 8.57%. As shown in Figure 1D, the true positive rates of Sets A, B, and C were 77.78%, 77.78%, and 91.43%, while the true negative rates were 81.82%, 91.67%, and 61.90%. As shown in Figure 1E, the false positive rates of Groups A, B, and C were 40.00%, 30.43%, and 45.45%, respectively, while the false negative rates were 24.14%, 5.26%, and 5.88%. As shown in Figure 1F, the true positive rates of Groups A, B, and C were 75.86%, 94.74%, and 94.12%, respectively, while the true negative rates were 60.00%, 69.57%, and 54.55%.

Figure 1.

Results of various indicators for diagnosing lymph node metastasis using different methods.

3.5. Diagnostic sensitivity analysis of palpation, color Doppler ultrasonography, and intensive CT examination in cervical lymph node metastasis

The sensitivity analysis between palpation, ultrasonography, and enhanced CT examination is shown in Table 5. Comparing enhanced CT and ultrasonography, the McNemar test showed that P = .156, therefore, there was statistically meaningless in sensitivity (P > .05). Comparing palpation results with ultrasonography (P < .05) and palpation results with enhanced CT scan (P < .05), therefore both were statistically different. In the Kappa concordance test, the sensitivity concordance between any 2 examinations was poor.

Table 5.

Sensitivity analysis between palpation, ultrasonography, and enhanced CT examination.

/		Intensive CT examination results
		Negative	Positive	Total
Ultrasound findings	Negative	2	4	6
	Positive	15	37	52
	Total	17	41	58

/		Palpation findings
		Negative	Positive	Total
Ultrasound findings	Negative	6	5	11
	Positive	16	31	47
	Total	22	36	58

/		Palpation findings
		Negative	Positive	Total
Intensive CT Inspection results	Negative	5	12	17
	Positive	19	22	41
	Total	24	34	58

3.6. Analysis of the diagnostic specificity of palpation, color Doppler ultrasonography, and intensive CT examination in cervical lymph node metastasis

The specificity analysis between palpation, ultrasonography, and enhanced CT examinations is shown in Table 6. Comparing enhanced CT and ultrasonography, after the McNemar test, P = .021, the specificity between them was different in statistic (P < .05). Comparing the results of palpation and ultrasonography, after McNemar test, P = .225, the specificity owns no difference in statistic (P > .05). Comparing the palpation results with the enhanced CT scan results, P = .003, there was a statistical difference between the 2 (P < .05). In the Kappa concordance test, the agreement of specificity between any 2 examinations was poor.

Table 6.

Analysis of specificity between palpation, ultrasonography, and enhanced CT examination.

/		Intensive CT examination results
		Negative	Positive	Total
Ultrasound findings	Negative	25	10	35
	Positive	2	3	5
	Total	27	13	40

/		Palpation findings
		Negative	Positive	Total
Ultrasound findings	Negative	34	2	36
	Positive	4	0	4
	Total	38	2	40

/		Intensive CT examination results
		Negative	Positive	Total
Palpation findings	Negative	23	16	39
	Positive	1	0	1
	Total	24	16	40

Figure 2 compares the consistency of sensitivity and specificity between different diagnostic methods. From Figure 2A, in the Kappa consistency test, the sensitivity consistency between any 2 inspection methods is poor (P > .05). From Figure 2B, it can be seen that in the Kappa consistency test, the specificity consistency between any 2 tests is also poor (P > .05).

Figure 2.

Sensitivity consistency and specificity consistency performance between different diagnostic methods.

3.7. ROC score of color Doppler ultrasonography with enhanced CT

Comparing the ROC scores of the diagnostic methods used by the color Doppler ultrasound inspection group and the intensive CT inspection group, the results of the 2 diagnostic methods are shown in Figure 3. In Figure 3, the AUC value was 0.965 for the color Doppler ultrasound inspection group and 0.842 for the intensive CT inspection group, with the ultrasound group being 0.123 higher than the CT group.

Figure 3.

ROC scores of CT group and ultrasound group.

3.8. Survival curves of different patients after color Doppler ultrasound and enhanced CT examination

Figure 4 exhibited the survival curves of patients in different groups after color Doppler ultrasound and enhanced CT examination. As the diagnosis time of patients increases, the survival curves of patients in different groups show a downward trend after ultrasound and CT examinations. However, the patient survival rate under final ultrasound examination was higher than that under CT examination, and the 2 had statistical significance (P < .05).

Figure 4.

Survival curves of patients in different groups after different diagnostic methods.

4. Discussion

Laryngeal cancer encompasses malignant tumors in the head and neck, categorized as primary and secondary types. Primary laryngeal cancer includes non-neuroendocrine laryngeal cancer.^[9,10] Secondary laryngeal malignancies occur after primary tumors and are commonly associated with respiratory tract malignancies, such as lung, gastric, and esophageal cancer. Among laryngeal cancer types, vocal fold-type laryngeal cancer is predominant, constituting up to 60%. Laryngeal cancer often leads to neck LNM, a common complication.^[11,12] Cervical LNM is a vital pathophysiological process in laryngeal cancer, providing crucial information for clinical treatment.

Hypopharyngeal cancer arises in the hypopharynx, located behind the nasal cavity, posterior pharyngeal wall, Eustachian tube, and oropharynx. It can be categorized into primary and secondary types. Primary hypopharyngeal cancer includes non-neuroendocrine, papillary, squamous, and lymphoepithelial types. Secondary hypopharyngeal cancer refers to tumors occurring after the primary tumor, mostly seen in malignant tumors of epithelial origin, such as nasopharyngeal and oral cavity cancer. Although hypopharyngeal cancer comprises only about 1.5% to 5.0% of head and neck tumors, patients often present in the middle to late stages due to its inconspicuous early symptoms and insidious location.^[13,14] The hypopharynx, rich in lymphatic tissues, facilitates cancer cell growth. Cancer cells originating from the hypopharynx circulate to the neck through lymphatic circulation early on, impacting clinical prognosis. Employing relevant techniques to assess whether LNM occurs in laryngeal and hypopharyngeal cancer significantly influences patient prognosis.

Doppler ultrasonography, utilizing the Doppler effect, is a medical imaging method for assessing tissue blood flow to facilitate diagnosis.^[15] Employing electronic devices and 2-dimensional ultrasound technology, Doppler ultrasonography visualizes blood flow in tissue, providing details about lymph node size, shape, location, and blood flow.^[16] Furthermore, Doppler ultrasound finds applications in examining other tissues, including the heart and blood vessels, for disease diagnosis and treatment planning. This study explored the efficacy and role of Doppler ultrasound in diagnosing cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers.^[17]

Initially, the study compared diagnostic results’ validity from palpation, color Doppler ultrasound, and enhanced CT with pathological diagnostic outcomes of actual patients. The analysis revealed a high agreement (Kappa > 0.61) (P < .05) between Doppler ultrasound results and pathological reports in both laryngeal and hypopharyngeal cancer patient groups. Although the long axis of a normal-sized cervical lymph node does not exceed 1.5 cm, its internal structure is intricate. Cancer cells entering lymph nodes first flow through the edges, subsequently entering the cortical layer, where they exhibit abnormalities and hypertrophy. These phenomena often result in eccentric cortical hypertrophy in metastatic lymph nodes, distinguishing it from the uniform cortical thickening seen in reactive hyperplastic lymph nodes.^[18,19] Metastatic lymph nodes in the neck fall into 2 categories: those with primary foci involving superficial nodes and those with metastatic foci in deeper nodes. Superficial nodes at the root of the neck are challenging to visualize in body ultrasound due to their deeper location.^[20] Consequently, ultrasound imaging diagnosis of cervical lymph nodes primarily relies on in-depth exploration.

Ultrasonography plays a crucial role in examining the internal structure of lymph nodes.^[21,22] In comparison to other medical tests, color Doppler ultrasonography offers significant advantages. In this study, palpation demonstrated a DS of 52.83% (28/53) and a specificity of 91.11% (41/45) in all patients with cervical lymph node metastases. Ultrasonography exhibited a DS of 77.78% (42/54) and a specificity of 81.82% (36/44) in all patients with cervical lymph node metastases. Intensive CT examination showed a DS of 75.86% (44/58) and a specificity of 60.00% (24/40) in all patients with cervical lymph node metastases. Color Doppler ultrasonography demonstrated superior DS and diagnostic specificity compared to intensive CT scans. Although intensive CT scans can visualize lymph nodes through enhancement, specific changes within them, such as the state of the dermatomedullary mass and blood supply to the lymph gates, are not clearly shown by this technique.^[23,24] Intensive CT scans are more inclined to depict the structural relationships between various tissues and structures, while ultrasound examination not only allows dynamic real-time observation of lesion changes but also displays hemodynamic parameters simultaneously, offering a multi-angle view of lesions. This facilitates the diagnosis and identification of diseases.^[25]

Currently, the criteria for determining the presence or absence of metastatic lymph nodes in the neck of laryngeal and hypopharyngeal cancer patients extend beyond clinical palpation methods.^[26,27] The application of color Doppler ultrasound technology addresses the limitations of palpation in diagnosing lymph node lesions and assessing the size, nature, and internal structure of lymph nodes. Asher pioneered the application of ultrasound diagnostic technology to lymph node diagnosis in 1969, and later, Bruneton utilized high-frequency real-time ultrasound at 7.5 MHz to detect lesions in surface lymph nodes in 1984. The use of high-resolution ultrasound technology enables a comprehensive scan of the patient’s surface lymph nodes, providing a detailed view of size, number, location, morphology, and internal structure.^[28,29] The combination of 2-dimensional gray-scale ultrasound and color Doppler imaging results in color Doppler ultrasound, offering new ideas and methods for elucidating the blood flow status of lymph nodes. This technique allows the observation of hemodynamic changes in lymph nodes under in vivo conditions and, when combined with functional imaging features, provides reliable evidence for further clarification of lymph node nature. During the surgical treatment of cervical LNM in laryngeal cancer, lymph nodes that cannot be reached, such as deep or occult metastasis in the neck, can be dynamically observed preoperatively through the multi-axis surface of color ultrasound.^[30]

This article still has some limitations. First, it is a single-center study, and there is a certain regional bias in the representativeness of the samples. However, the study attempted to adopt a randomized grouping method to ensure comparability between the 2 groups, and the results have a certain significance. Additionally, due to the need to ensure patient compliance, the sample size in this study is limited, and there may be a situation where the positive rate and negative rate approach stability with the increase of sample size. However, this phenomenon was not evident in the present study. In future research, it is anticipated to expand the sample size and enhance multicenter representation to address the ethical shortcomings of the experiment.

In conclusion, the sensitivity and specificity of color Doppler ultrasonography in the diagnosis of cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers are better than that of intensive CT scan. The use of color Doppler ultrasonography in the diagnosis of cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers can assist physicians in diagnosing patients’ conditions in a timely manner and in selecting more effective treatment plans for patients. The base number of patients included in this study was small, so the above results may have some chance, thus affecting the correct rate of the experiment. In the follow-up study, more samples should be added to avoid the influence of chance errors.

Author contributions

Conceptualization: Kailan Xiao, Yan Xiao, Shuhua Liu.

Data curation: Kailan Xiao, Yan Xiao.

Formal analysis: Kailan Xiao, Yan Xiao, Shuhua Liu.

Investigation: Kailan Xiao, Shuhua Liu.

Methodology: Kailan Xiao, Shuhua Liu.

Writing – original draft: Kailan Xiao, Yan Xiao, Shuhua Liu.

Writing – review & editing: Kailan Xiao, Shuhua Liu.