Ultrasound usage in the head and neck surgeon's office

Perfusion analysis of benign parotid gland tumors by contrast-enhanced ultrasonography (CEUS)

BACKGROUND

Diagnosis of parotid gland tumors is sometimes challenging due to their diversity and pleomorphic histological appearance. B-scan sonography along with color-coded duplex sonography is the gold standard in the diagnostic workup of these lesions, whereas histopathology is to date the gold standard for the final diagnosis. To date no single imaging technique provides the chance for an art-diagnosis with highly diagnostic accuracy. Contrast enhanced ultrasonography (CEUS) on the other hand provides information of the perfusion down to the capillary level. Currently there are only a few papers published with systematical examination of the perfusion in benign parotid gland tumors and its diagnostic significance.

PATIENTS AND METHODS

One hundred patients with a parotid gland tumor were examined. The examinations included conventional B-scan sonography, color-coded duplexsonography along with contrast enhanced ultrasonography (CEUS). B-scan sonographic parameters, i.e. echogenicity, shape, size, demarcation, and borders of a lesion along with vascularization estimated by color-coded-duplexsonography were analyzed. Analysis of quantitative CEUS parameters was performed using 8 regions of interest (ROI), which were standardized located throughout the entire tumors. The perfusion parameters were analyzed for particular tumor entities. Qualitative CEUS analysis with estimating the perfusion pattern was additionally performed.

RESULTS

Histological examination revealed benign tumors in 92 cases, with pleomorphic adenomas and Warthin´s tumors were the most frequent entities. Malignant conditions were found in 8 cases. CEUS revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. CEUS showed a significant heterogenic perfusion in all tumors, with a higher perfusion in the medial parts of the tumors and in some cases also in the center. Perfusion patterns of PA and WT were different. WT displayed centrifugal, centripetal, and central diffuse perfusion more often than PA, whereas in PA perfusion often was limited to the capsule or periphery. Oncocytoma had the highest perfusion values. Intraglandular cysts showed no intralesional perfusion.

CONCLUSIONS

CEUS analysis in different parts of benign tumors revealed a significant heterogeneity in tumor perfusion. Some perfusion pattern could be identified which might be characteristic for particular lesions. Based on this, the diagnostic accuracy of CEUS in the differential diagnosis of parotid gland tumors can be increased. In particular, the perfusion analysis within the tumors using ROIs located standardized throughout the entire tumor provides additional information which are important for the art diagnosis and in differentiation of tumor entity.

[Perfusion analysis in parotid gland tumors using contrast-enhanced ultrasound (CEUS)]

OBJECTIVE

The diagnosis of parotid gland tumors is challenging due to their rarity and heterogenity. Neither conventional ultrasound nor magnetic resonance imaging (MRI) nor computed tomography (CT) allow a reliable pretherapeutic diagnosis. In addition to conventional ultrasound, contrast-enhanced ultrasound (CEUS) enables a more detailed assessment of perfusion in parotid gland tumors, thereby improving evaluation of this tumor entity. Extensive studies with analysis of perfusion characteristics in different regions of interest (ROI) in parotid gland tumors are currently lacking. This study analysed and compared perfusion parameters in different intratumoral areas of malignant and benign parotid gland tumors using CEUS.

MATERIALS AND METHODS

A total of 100 patients with tumors in the parotid gland were examined using B‑mode sonography, colour Doppler sonography and CEUS. The parameters magnitude, echogenicity, demarcation, vascularisation and in particular perfusion characteristics were measured and analysed. Analysis of quantitative CEUS parameters was performed using a specific method for perfusion analysis with certain ROI, which were allocated in a standardized manner in the entire parotid gland tumors. The perfusion parameters were compared between intratumoral ROI in the tumors and between particular tumor entities. Qualitative CEUS analysis with an estimation of perfusion patterns was additionally performed.

RESULTS

Histologically benign tumors were found in 92 cases, and malignant tumors in eight cases. CEUS analysis of perfusion patterns revealed a centripetal perfusion pattern in malignant tumors significantly more frequently than in benign tumors. In the perfusion analysis of quantitative CEUS parameters, all tumors showed higher perfusion intensities in the peripheral ROI. In benign tumors, more differences in perfusion intensity between the intratumoral ROIs were detected compared to malignant tumors.

CONCLUSION

The perfusion parameters (centripetal perfusion pattern; area under the curve) evaluated in this study have the potential to improve pretherapeutic diagnostics of parotid gland tumors in terms of differentiation of tumor entity. Further studies with larger patient cohorts are required for subsequent investigation and validation of the diagnostic accuracy of particular parameters to detect perfusion patterns potentially specific to particular tumor entities.

Point-of-care ultrasound in otolaryngology and head and neck surgery: A prospective survey study

PURPOSE

The ultrasound applications, examination facilities and methods used by otolaryngology and head and neck surgeons may vary and be different. This study was conducted to assess the methods used for head-and-neck point-of-care ultrasound (POCUS).

METHODS

This prospective survey study was conducted from 1 July 2018 to 31 December 2019. The surgeons of otolaryngology and head neck surgery who used POCUS in their daily practice were recruited for analyses.

RESULTS

In total, 30 male and 14 female surgeons who used neck POCUS were recruited. Thirty-nine (89%) surgeons placed patients in a supine position with the head toward the operator. Forty (91%) surgeons performed US-guided fine needle aspiration (FNA), and 35 (80%) surgeons did not use local anesthesia during US-FNA. Thirty-nine (88%) surgeons used the long-axis method to harvest the specimen, and forty-one (93%) used a free-hand method. Most surgeons (25, 57%) used 22G needles for US-FNA, and 29 (66%) used 18G for US-guided core-needle biopsy (CNB). For the cost analysis, reimbursements for US-related procedures were relatively cheaper than those for computer tomography (CT) and magnetic resonance imaging (MRI).

CONCLUSION

POCUS can be performed by otolaryngology and head and neck specialists with a wide scope of applications and in a cost-effective manner.

Anatomic factors affecting the use of ultrasound to predict vocal fold motion: A pilot study

PURPOSE

Ultrasonography is a well-established modality for visualization of head and neck anatomy. Using ultrasound to detect vocal fold mobility has been described before, but no study has evaluated factors affecting the exam reliability. The aim of the study is to determine anatomic factors influencing the reliability of ultrasound to detect vocal fold motion. Methods and materials Patients underwent ultrasound evaluation and flexible laryngoscopy to assess vocal fold motion from August 2015 to March 2016. Length, accuracy, and clarity of ultrasound examination were assessed, compared to flexible laryngoscopy. For patients with prior neck CT scan imaging, laryngeal anatomy was independently assessed by a blinded neuroradiologist.

RESULTS

A total of 23 patients, 21 with bilateral vocal fold motion and two with unilateral paralysis, were enrolled. Vocal folds were visible in 19 patients (82%). Eight patients (42%) had good/excellent view and 11 patients (58%) had fair/difficult view. The ultrasound correctly detected absent movement of the vocal fold in the two patients with unilateral paralysis. A total of 19 patients had CT scans, and a linear correlation (r² = 0.65) was noted between the anterior thyroid cartilage angle measured on CT and the grade of view on ultrasound.

CONCLUSION

Ultrasound was able to detect vocal fold motion in 82% of randomly screened patients. Ease of detection of vocal fold motion correlated with the anterior thyroid angle. Further studies are warranted to investigate the reproducibility of our results and how this might impact use of ultrasound for detection of vocal fold motion in the operative setting.

Evaluation of the American college of surgeons thyroid and parathyroid ultrasound course: Results of a web-based survey

OBJECTIVES/HYPOTHESIS

The American College of Surgeons Thyroid and Parathyroid Ultrasound Skills-Oriented Course (TPUSC) was designed to teach surgeons how to interpret and perform office-based head and neck ultrasound (HNUS). The objective of this study was to survey attendees of the TPUSC to evaluate the usefulness of the course, to track surgeon performed HNUS practice patterns, and to help identify potential roadblocks to incorporation of HNUS into a surgeon's practice.

STUDY DESIGN

Cross-sectional survey.

METHODS

A Web-based survey was sent to 952 surgeons who completed the TPUSC between 2010 and 2014. Questions included surgeon specialty, practice type, Likert scale rating of the TPUSC, competency with different HNUS procedures, and current HNUS practice patterns.

RESULTS

The response rate was 24%. On a scale from 1 (not useful) to 5 (extremely valuable), the mean course usefulness rating was 4.2. Educational goals were met for 194 (92%) surgeons, and 162 (77%) surgeons reported performing HNUS in their practice. Of 48 surgeons not performing HNUS, 24 (50%) attributed insufficient time in their clinic schedule, and 21 (44%) attributed high equipment costs.

CONCLUSIONS

The TPUSC is a valuable educational experience for surgeons seeking to gain proficiency in HNUS. The majority of TPUSC graduates gain competency with at least one type of HNUS procedure following the course.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:1950-1958, 2017.

Ultrasound backscatter microscopy for imaging of oral carcinoma

OBJECTIVES

Ultrasound backscatter microscopy (UBM), or ultrasound biomicroscopy, is a noninvasive, label-free, and ionizing radiation-free technique allowing high-resolution 3-dimensional structural imaging. The goal of this study was to evaluate UBM for resolving anatomic features associated with squamous cell carcinoma of the oral cavity.

METHODS

The study was conducted in a hamster buccal pouch model. A carcinogen was topically applied to cheeks of 14 golden Syrian hamsters. Six additional hamsters served as healthy controls. A high-frequency (41 MHz, 6-mm focal depth, lateral and axial resolutions of 65 and 37 μm, respectively) UBM system was used for scanning the oral cavity after 14 weeks of carcinogen application. Histologic analyses were conducted on scanned regions.

RESULTS

The histologic structure of buccal tissue and microvasculature networks could be visualized from the UBM images. Epithelial and mucosal hypertrophy and neoplastic changes were identified in animals subjected to the carcinogen. In animals with invasive squamous cell carcinoma, lesion development and destruction of the structural integrity of tissue layers were noted.

CONCLUSIONS

In this pilot study, UBM generated sufficient contrast for morphologic features associated with oral carcinoma compared to healthy tissue. This modality may present a practical technique for detection of oral neoplasms that is potentially translatable to humans.

In vivo validation of a bimodal technique combining time-resolved fluorescence spectroscopy and ultrasonic backscatter microscopy for diagnosis of oral carcinoma

Tissue diagnostic features generated by a bimodal technique integrating scanning time-resolved fluorescence spectroscopy (TRFS) and ultrasonic backscatter microscopy (UBM) are investigated in an in vivo hamster oral carcinoma model. Tissue fluorescence is excited by a pulsed nitrogen laser and spectrally and temporally resolved using a set of filters/dichroic mirrors and a fast digitizer, respectively. A 41-MHz focused transducer (37-μm axial, 65-μm lateral resolution) is used for UBM scanning. Representative lesions of the different stages of carcinogenesis show that fluorescence characteristics complement ultrasonic features, and both correlate with histological findings. These results demonstrate that TRFS-UBM provide a wealth of co-registered, complementary data concerning tissue composition and structure as it relates to disease status. The direct co-registration of the TRFS data (sensitive to surface molecular changes) with the UBM data (sensitive to cross-sectional structural changes and depth of tumor invasion) is expected to play an important role in pre-operative diagnosis and intra-operative determination of tumor margins.

Ultrasound-guided fine-needle aspiration of the tongue base: a cadaver feasibility study

OBJECTIVE

The authors hypothesize that floor-of-mouth and tongue base anatomy can be visualized with ultrasound and that ultrasound can be used to accurately guide needle placement and dye injection into the tongue base, serving as a surrogate for fine-needle aspiration.

STUDY DESIGN

Observation of experimental intervention.

SETTING

Medical school cadaver anatomy laboratory.

SUBJECTS AND METHODS

Ultrasound imaging was performed on human cadaveric specimens to visualize the anatomy of the floor of mouth and base of tongue in a midline transcervical approach. Methylene blue dye was injected under ultrasound guidance into the base of tongue. Specimens were dissected, and results were counted and analyzed.

RESULTS

Twenty-five of 32 (78%) cadaver specimens were found to have correct placement of dye within the posterior genioglossus and intrinsic tongue musculature. Seven cadavers did not have correct placement of dye. Of these, 3 had dye staining the walls of the oropharynx and epiglottis. Two specimens had dye injected erroneously into the geniohyoid muscles. One patient was found to have had a partial glossectomy. Difference in neck circumference was not significant between those with correct (mean, 37.9 cm) and incorrect (mean, 37.4 cm) dye placement (P = .75).

CONCLUSION

Anatomy of the floor of mouth and tongue base can be readily depicted with ultrasonography. After reasonable success of injecting dye into cadaver tongue bases, the authors conclude that there appears to be a future clinical role for ultrasound-guided fine-needle aspiration of the tongue base for tongue base lesions.

Clinical utility and prospective comparison of ultrasonography and computed tomography imaging in staging of neck metastases in head and neck squamous cell cancer in an Indian setup

BACKGROUND

Preoperative lymph node screening of all neck compartments is favored by clinicians for the management of the neck. The presence of a metastatic node on one side of the neck reduces the 5-year survival rate to 50%, and the presence of a metastatic node on both sides of the neck reduces the 5-year survival rate to 25%.

MATERIALS AND METHODS

This study compared the evaluation of lymph node metastases by ultrasonography (USG) and computed tomography (CT) in patients with squamous cell cancer of the head and neck region.

RESULTS

Five hundred and eighty-four patients with squamous cell cancer of the head and neck were prospectively evaluated for the presence of cervical lymph node metastases. All patients underwent clinical examination (palpation), USG and CT imaging. Neck dissection was performed in all the patients, and the results of the preoperative evaluation were correlated with the surgical and histopathological findings. Metastases in neck nodes were identified in 148 patients by histopathological examination. Doppler USG correctly identified 136 node-positive patients (n = 148; sensitivity 91.8%, specificity 97%). CT imaging correctly identified 122 patients with metastatic lymph nodes (n = 148; sensitivity 83%, specificity 93%). Positive predictive values of USG and CT imaging were 95.6% and 91.3%, respectively, whereas the negative predictive values of these two imaging studies were 95.4% and 89.6%, respectively.

CONCLUSIONS

The accuracy and sensitivity of USG in detection of cervical lymph node metastases make it a potentially promising and cheap preoperative tool for staging neck node metastases and optimizing the treatment plan for surgeons, especially in countries such as India.

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.

[Sonographic differential diagnosis of cervical masses]

One of the main indications for the use of ultrasound by the head and neck specialist is the diagnosis of cervical masses. The examination can be easily performed since all structures of interest are located superficially and are not covered by boney or air-filled structures. Further advantages of ultrasound in contrast to other imaging techniques such as MRI or CT include its high resolution and lack of side effects. Even structures of <5 mm in diameter can be interpreted well. Since ultrasound is fast, has no side effects and can be performed as often as necessary, it represents an excellent diagnostic instrument in the follow-up of patients with head and neck cancer. In addition to the conventional B-scan technique, colour duplex sonography is also often performed today to obtain additional information on the nature of cervical masses. Thus, different entities of cervical lymph nodes can be well differentiated by their pattern of vascularization.