[Intraoperative endosonographic guided resection of tongue carcinoma]

Noninvasive Imaging Methods to Improve the Diagnosis of Oral Carcinoma and Its Precursors: State of the Art and Proposal of a Three-Step Diagnostic Process

Simple Summary

Oral squamous cell carcinoma (OSCC) accounts for 90–95% of malignant tumors of the lip and oral cavity and is associated with high mortality in the advanced stages. Early diagnosis is a challenge for oral pathologists and dentists, due to the ambiguous appearance of early OSCC, which is often misdiagnosed, mistreated, and associated with diagnostic delay. The gold standards for OSCC diagnosis are biopsy and histopathological assessment, but these procedures are invasive and time-consuming. Adjunctive noninvasive techniques allow the definition of the malignant features of a suspicious lesion in real time and noninvasively, thus improving the diagnostic procedure. The present review aimed to focus on some of the main promising noninvasive imaging techniques, to highlight their perspective adoption in a three-step diagnosis, which is idealistically faster and better, as well as enables the patient’s compliance.

Abstract

Oral squamous cell carcinoma (OSCC) is the most prevalent form of cancer of lips and oral cavity, and its diagnostic delay, caused by misdiagnosis at the early stages, is responsible for high mortality ratios. Biopsy and histopathological assessment are the gold standards for OSCC diagnosis, but they are time-consuming, invasive, and do not always enable the patient’s compliance, mainly in cases of follow-up with the need for more biopsies. The use of adjunctive noninvasive imaging techniques improves the diagnostic approach, making it faster and better accepted by patients. The present review aims to focus on the most consolidated diagnostic techniques, such as vital staining and tissue autofluorescence, and to report the potential role of some of the most promising innovative techniques, such as narrow-band imaging, high-frequency ultrasounds, optical coherence tomography, and in vivo confocal microscopy. According to their contribution to OSCC diagnosis, an ideal three-step diagnostic procedure is proposed, to make the diagnostic path faster, better, and more accurate.

Utility of intraoral ultrasound in managing oral tongue squamous cell carcinoma: Systematic review

OBJECTIVES/HYPOTHESIS

Adequate surgical resection of early stage oral tongue cancer provides the best chance at preventing locoregional disease recurrence. Determination of tumor dimensions and margin location is challenging and can lead to inadequate resections with close/positive margins. Ultrasonography has proven its utility in determining the thickness and extent of tongue tumors. Preoperative tumor dimension measurements carry increased significance with the addition of depth of invasion (DOI) to the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging system. We report the results of a systematic review of the literature pertaining to the use of ultrasound in the diagnosis and management of oral tongue carcinoma.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis statement checklist was used to inform the design of this systematic review. All studies that utilized ultrasound in the diagnosis/management of primary carcinoma of the oral tongue were included. PubMed, Embase, and Cochrane were reviewed to identify eligible studies.

RESULTS

Nineteen articles were included in our analysis. Six hundred seventy-eight patients were studied in the articles included. Ultrasound tumor thickness measurements correlate well with those on histopathology and show promise as a predictor of cervical lymph node metastasis. Ultrasound can be safely used intraoperatively for deep margin assessment.

CONCLUSIONS

Ultrasound is useful in the evaluation of oral tongue malignancies. More experience is needed to determine if it is reliable in determining preoperative DOI in light of the role this tumor parameter plays in the eighth edition of the AJCC staging manual. Laryngoscope, 129:662-670, 2019.

Preoperative ultrasonography for tumor thickness evaluation in guiding management in patients with early oral tongue squamous cell carcinoma

Objectives:

(1) To assess the statistical correlation between the tumor thickness (TT) by ultrasonography (USG) and microscopic measurement in cases of early oral tongue squamous cell carcinoma (OTSCC). (2) To assess the predictive capacity of TT by ultrasound in detecting nodal metastasis.

Materials and Methods:

Prospective analysis was performed in 24 patients for a period of 2 years from 2012 to 2013. Nodal status and TT measurement was done preoperatively by neck and intraoral USG respectively in cases of early (pT1 & T2, clinically N0) OTSCC. As per the institution protocol after histopathological confirmation of malignancy, all patients underwent resection of primary lesion and ipsilateral elective neck dissection (Level - I to IV). Measurement of TT was obtained intraoperatively from fresh glossectomy specimen and postoperatively from histopathological paraffin section examination. The statistical correlation between TT measured by USG and histopathology was assessed by Pearson's correlation coefficient. Chi-square test was used to find the association of pathological T stage, TT with pathological nodal status.

Results:

Significant statistical correlation was seen between TT by USG and microscopic measures. Between the two, TT measurements were within 1 mm in 37.5% (9/24) of cases, within 2 mm in 29.16% (7/24), and was greater than 2 mm in 8 cases. The Pearson's correlation r is 0.678 (P < 0.001) and ICC (interclass correlation coefficient) is 0.808. The average difference between microscopic and US thickness (Bias) is -0.14637 and the limits of agreement is (4.717, -4.863) with 95% limits of agreement. The rate of occult nodal metastasis was 16.6% and TT of <4 mm had no incidence of nodal metastasis.

Conclusion:

Ultrasonographic evaluation is reliable and cost-effective tool to measure the TT preoperatively, which will be of help in deciding the management in early OTSCC. TT of 4 mm and above was predictor of occult cervical nodal metastasis.

Endocavitary sonography of early oral cavity malignant tumors

BACKGROUND

Preoperative staging is crucial for oral cancer management. The purpose of this study was to assess the tumor thickness using ultrasound and to correlate the level of histological infiltration with the tumor superficial extension and lesion thickness.

METHODS

Thirty-two subjects affected by oral cavity carcinoma were prospectively evaluated with intraoral ultrasound. The ultrasound sensitivity, the correlation between the ultrasound level of infiltration, and lesion diameters and thickness were assessed.

RESULTS

A 91% ultrasound sensitivity was found with no significant correlation between tumor diameter and level of histological infiltration (P >.05). A thickness of <2 mm was associated to tumor extension to the lamina propria, a value of >6 mm to muscular layer infiltration. Lymph adenopathies were identified in 21% of cases, associated to muscular layer infiltration in all cases.

CONCLUSION

In the study of early oral cavity tumors, ultrasound is accurate for demonstrating the level of tumor infiltration and contributes to the therapeutic choice.

[New developments in computer-assisted surgery (CAS). From intraoperative imaging to ultrasound-based navigation]

Ever faster processor capacity is having an impact on computer-assisted or computer-aided surgery (CAS). The fusion of different imaging modalities enables functional data such as PET-CT, for example, to be available in image-guided surgery. Referencing of image data is the key to precise navigation. Intraoperative data acquisition is a new approach to improving accuracy. Thus, intraoperative CT conducted under navigational support enables automatic referencing of up-to-date image data. Alternatively, intraoperative magnetic resonance imaging or intraoperative sonography can be performed. Ultrasound systems have already been successfully integrated in existing navigational systems to compensate for intraoperative tissue shifting. Ultrasound systems may play a role in the future as a single modality in image-guided surgery in soft tissue of the neck and skull bone.

Error analysis for determination of accuracy of an ultrasound navigation system for head and neck surgery

OBJECTIVE

The use of conventional CT- or MRI-based navigation systems for head and neck surgery is unsatisfactory due to tissue shift. Moreover, changes occurring during surgical procedures cannot be visualized. To overcome these drawbacks, we developed a novel ultrasound-guided navigation system for head and neck surgery. A comprehensive error analysis was undertaken to determine the accuracy of this new system.

MATERIALS AND METHODS

The evaluation of the system accuracy was essentially based on the method of error definition for well-established fiducial marker registration methods (point-pair matching) as used in, for example, CT- or MRI-based navigation. This method was modified in accordance with the specific requirements of ultrasound-guided navigation. The Fiducial Localization Error (FLE), Fiducial Registration Error (FRE) and Target Registration Error (TRE) were determined.

RESULTS

In our navigation system, the real error (the TRE actually measured) did not exceed a volume of 1.58 mm(3) with a probability of 0.9. A mean value of 0.8 mm (standard deviation: 0.25 mm) was found for the FRE. The quality of the coordinate tracking system (Polaris localizer) could be defined with an FLE of 0.4 +/- 0.11 mm (mean +/- standard deviation). The quality of the coordinates of the crosshairs of the phantom was determined with a deviation of 0.5 mm (standard deviation: 0.07 mm).

CONCLUSION

The results demonstrate that our newly developed ultrasound-guided navigation system shows only very small system deviations and therefore provides very accurate data for practical applications.

Navigation-supported and sonographically-controlled fine-needle puncture in soft tissues of the neck

In surgery, sonography has been a well-accepted means of orientation for years. The immediate vicinity of many vital structures in the head and neck region calls for a very exact visualization of the surgical instrument in the 2-D ultrasonic picture. We report on the development of a new method for navigation-supported and sonographically-controlled fine-needle puncture in soft tissues of the neck. Our system comprises a navigated ultrasound probe, a navigated fine-puncture needle and a coordinate sensor. A personal computer with specially-developed software assists calibration and surgical application. The applicability test for the system is described. In vitro, a model lymph node of 9 mm in diameter had been hit. It is shown that the target structure can be aimed at very precisely by the navigated puncture needle. An accuracy of 97% and a specificity of 99% could be demonstrated. The development of a very precise and easy-to-handle method for navigation-supported fine-needle puncture in the neck region is presented. The outstanding advantage of this method is that no rigid reference gadget fixed to the patient's body is necessary. That makes this method very suitable for surgery in the neck region. Contrary to other sonographically-supported navigation methods in the head and neck region, preoperative imaging (CT or MRT) is dispensable.

Intraoral Sonography–Assisted Resection of T1–2 tongue Cancer for Adequate deep Resection

Objective

To investigate the clinical usefulness of intraoral sonography-assisted resection for securing adequate deep resection margins in T1–2 tongue cancers.

Study Design

Prospective clinical trial.

Materials and Methods

Twenty consecutive patients with clinical T1–2 tongue cancers were enrolled and their lesions were removed by intraoral sonography-assisted resection. We then retrospectively collected data from 20 T stage-matched patients without intraoral sonography-assisted resection as the control group. All resections were performed with a goal of 15 mm margin. The mucosal and deep safety margins were compared between the two groups.

Results

Intraoral sonography could predict the paraffin-embedded tumor thickness with an error of 3.16 ± 2.24 mm. The deep safety margins were more adequate for intraoral sonography–assisted resection (9.8 ± 5.2 mm) than for conventional resection (4.0 ± 2.03 mm) ( P < 0.001), while the mucosal safety margins were not different

Conclusion

Intraoral sonography-assisted resection provides a more adequate deep resection margin for early T-stage tongue cancers.

[Navigation-assisted sonography for soft tissues in the head and neck region]

BACKGROUND

In soft tissue surgery of the head and neck region tissue shifts limit the usefulness of conventional CT/MRI-based navigation procedures. Furthermore, changes caused by invasive measures cannot be visualized.

METHODS

A novel navigation device for sonography of soft tissues was developed. This consists of a navigated ultrasound scanner, a navigated surgical instrument, and a personal computer with custom-made software. Its use makes an additional visualization by means of CT or MRI dispensable.

RESULTS

The system deviation (three-dimensional error) of this newly developed prototype was less than 1 mm. The practical application in a model setup showed good handling properties of the system. Orientation and approach of the surgical instrument to the sonographically visualized target structure were rapid and accurate.

CONCLUSION

This new navigation system does not require additional CT or MRI images. The navigated ultrasound probe shows tissue changes in real time. This navigation system is especially suitable for invasive procedures in soft tissues.