Anatomical landmarks for transoral robotic tongue base surgery: comparison between endoscopic, external and radiological perspectives

Machine learning-based MRI radiomics for assessing the level of tumor infiltrating lymphocytes in oral tongue squamous cell carcinoma: a pilot study

BACKGROUND

To investigate the value of machine learning (ML)-based magnetic resonance imaging (MRI) radiomics in assessing tumor-infiltrating lymphocyte (TIL) levels in patients with oral tongue squamous cell carcinoma (OTSCC).

METHODS

The study included 68 patients with pathologically diagnosed OTSCC (30 with high TILs and 38 with low TILs) who underwent pretreatment MRI. Based on the regions of interest encompassing the entire tumor, a total of 750 radiomics features were extracted from T2-weighted (T2WI) and contrast-enhanced T1-weighted (ceT1WI) imaging. To reduce dimensionality, reproducibility analysis by two radiologists and collinearity analysis were performed. The top six features were selected from each sequence alone, as well as their combination, using the minimum-redundancy maximum-relevance algorithm. Random forest, logistic regression, and support vector machine models were used to predict TIL levels in OTSCC, and 10-fold cross-validation was employed to assess the performance of the classifiers.

RESULTS

Based on the features selected from each sequence alone, the ceT1WI models outperformed the T2WI models, with a maximum area under the curve (AUC) of 0.820 versus 0.754. When combining the two sequences, the optimal features consisted of one T2WI and five ceT1WI features, all of which exhibited significant differences between patients with low and high TILs (all P < 0.05). The logistic regression model constructed using these features demonstrated the best predictive performance, with an AUC of 0.846 and an accuracy of 80.9%.

CONCLUSIONS

ML-based T2WI and ceT1WI radiomics can serve as valuable tools for determining the level of TILs in patients with OTSCC.

Scientific Status Quo of Small Renal Lesions: Diagnostic Assessment and Radiomics

Background: Small renal masses (SRMs) are defined as contrast-enhanced renal lesions less than or equal to 4 cm in maximal diameter, which can be compatible with stage T1a renal cell carcinomas (RCCs). Currently, 50-61% of all renal tumors are found incidentally. Methods: The characteristics of the lesion influence the choice of the type of management, which include several methods SRM of management, including nephrectomy, partial nephrectomy, ablation, observation, and also stereotactic body radiotherapy. Typical imaging methods available for differentiating benign from malignant renal lesions include ultrasound (US), contrast-enhanced ultrasound (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI). Results: Although ultrasound is the first imaging technique used to detect small renal lesions, it has several limitations. CT is the main and most widely used imaging technique for SRM characterization. The main advantages of MRI compared to CT are the better contrast resolution and tissue characterization, the use of functional imaging sequences, the possibility of performing the examination in patients allergic to iodine-containing contrast medium, and the absence of exposure to ionizing radiation. For a correct evaluation during imaging follow-up, it is necessary to use a reliable method for the assessment of renal lesions, represented by the Bosniak classification system. This classification was initially developed based on contrast-enhanced CT imaging findings, and the 2019 revision proposed the inclusion of MRI features; however, the latest classification has not yet received widespread validation. Conclusions: The use of radiomics in the evaluation of renal masses is an emerging and increasingly central field with several applications such as characterizing renal masses, distinguishing RCC subtypes, monitoring response to targeted therapeutic agents, and prognosis in a metastatic context.

Exploring Radiologists' Burnout in the COVID-19 Era: A Narrative Review

Since its beginning in March 2020, the COVID-19 pandemic has claimed an exceptionally high number of victims and brought significant disruption to the personal and professional lives of millions of people worldwide. Among medical specialists, radiologists have found themselves at the forefront of the crisis due to the pivotal role of imaging in the diagnostic and interventional management of COVID-19 pneumonia and its complications. Because of the disruptive changes related to the COVID-19 outbreak, a proportion of radiologists have faced burnout to several degrees, resulting in detrimental effects on their working activities and overall wellbeing. This paper aims to provide an overview of the literature exploring the issue of radiologists' burnout in the COVID-19 era.

Transoral robotic surgery of the tongue base for obstructive sleep apnea: Preliminary results

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is a major public health issue. Robotic tongue-base reduction surgery is being developed, but needs assessment. The present study reports clinical and polygraphic results at 6 months' follow-up.

METHOD

Single-center prospective study of 8 patients undergoing transoral robotic surgery (TORS) for severe OSAS.

RESULTS

Mean age was 47 years. M/F sex ratio was 5:3. Initial body-mass index ranged from 18 to 35kg/m². Mean Epworth score was 12. Mean preoperative apnea-hypopnea index (AHI) was 47 (range, 36-60). At 6 months, only 1 patient did not meet usual success criteria (AHI<20 with>50% decrease); 2 patients had residual AHI between 10 and 20; the other 5 had non-significant event rates.

CONCLUSION

TORS tongue-base reduction showed promising results, which need confirmation on long-term multicenter studies.

Radiographic and histologic characterization of tongue base tissues obtained by transoral robotic surgery in patients with obstructive sleep apnea

OBJECTIVE

Our aim was to radiographically and histologically characterize the tongue base tissues removed after robotic surgery and to analyze their relationship with polysomnographic measurements in obstructive sleep apnea.

METHODS

Medical records, radiographs and histologic specimen of the patients who underwent transoral robotic tongue base reduction surgery were retrospectively reviewed. Findings in computed tomography (CT) images, histopathological features of the removed tongue base tissues, and respiratory parameters in polysomnography were compared and analyzed.

RESULTS

Surgical specimens and CT images were available from 13 patients (aged 29-61 years). Histologic examination showed that the removed tissues comprised four layers-epithelial, lymphoid follicular, glandular, and muscle tissue. The median (interquartile range) thickness of the epithelial, lymphoid, and glandular layers was 0.29 (0.24-0.44) mm, 3.37 (1.67-4.75) mm, and 3.75 (3.45-4.10) mm, respectively. The lymphoid layer thickness on CT was correlated with that in the histologic section (r=0.967, p<0.001). However, the thickness of each layer had no significant correlation with the polysomnographic parameters.

CONCLUSION

The tongue base tissue removed by transoral robotic surgery in OSA patients comprised four distinctive layers including epithelial, lymphoid follicular, glandular and muscular layers. These layered structures could also be discriminated in the CT images.

Configuration of the extrinsic muscles of the tongue and their spatial interrelationships

PURPOSE

The tongue is a highly muscular organ, and the extrinsic muscles of the tongue overlap one another, which makes their configuration intricate. The aim was to clarify their spatial interrelationships.

METHODS

The extrinsic muscles of the tongue were gross anatomically investigated in 42 cadavers.

RESULTS

The hyoglossus consisted of two parts arising from the hyoid body and the greater horn, respectively. They ascended to the tongue external to the genioglossus. The quadrilateral anterior part contained several parallel bundles, and the triangular posterior part comprised of three bundles converging to the insertion. The genioglossus consisted of many compartments. Although its fibers radiated from the mental spine to the tongue internal to the inferior longitudinal muscle, the lateral fibers of the inferior parts passed externally to it, and the most inferior part attached to the hyoid bone and the epiglottis. The chondroglossus arising from the lesser horn ascended internally to the lateral fibers of the inferior parts. The styloglossus arising from the styloid process coursed externally and internally to the hyoglossus and between its two parts. The external and internal bundles fused with the fibers of the palatoglossus and the superior pharyngeal constrictor, respectively. Three bundles were inserted into the apex with the inferior longitudinal muscle or joined the inferior parts of the genioglossus.

CONCLUSIONS

The extrinsic muscles are subdivided into small groups of fibers depending on their spatial interrelationships, suggesting that they contain many functional units. Some units act separately, and others cooperate across the traditional boundaries of the muscles.

Transoral Robotic Partial Glossectomy and Supraglottoplasty for Obstructive Sleep Apnea

The standard treatment for patients with obstructive sleep apnea syndrome is positive airway pressure (PAP) therapy. However, when PAP therapy fails, surgery may be an option to alleviate the obstruction. The base of tongue plays an important role in this obstruction, and addressing the tongue base surgically can be a challenge for the head and neck surgeon. Transoral robotic surgery (TORS) using the da Vinci Surgical System provides a safe and effective way to approach and manage the base of tongue and supraglottis. Advantages of TORS include wide-field high-definition 3-D visualization, precise instrumentation, and when compared with open procedures, less operative time, quicker recovery, no external scars, and comparable tissue resection.

Arterial Anastomosis in the Tongue

PURPOSE

Radical surgery for neoplasms of the tongue can endanger at least 1 lingual artery, threatening the survival of the remaining tissue and the recovery of speech and swallowing. Although there is little anastomosis in the substance of the tongue, this study investigated whether arterial anastomoses outside the tongue could provide collateral circulation to protect the surviving tissue.

MATERIALS AND METHODS

Parts of 9 embalmed cadaver heads were examined. In 2 specimens, the arteries had been previously injected with latex and India ink. In the remaining, a mixture of latex and India ink was injected into the lingual artery at its origin on 1 side. Five injections were successful.

RESULTS

There was considerable variation in the course and distribution of the lingual arteries. Arteries did not cross the midline of the tongue, but actual or potential anastomoses could be seen round the base of the tongue, in the floor of the mouth, and with facial artery branches. After the experimental injections, the mass filled the lingual artery and its branches on the injected side, but also reached the trunk and main branches of the opposite side.

CONCLUSION

A mass injected into the lingual artery of 1 side can reach the trunk and territory of the lingual artery of the opposite side. In life, it is likely that a similar collateral circulation would exist. Some clinical literature supports this conclusion, but preoperative arteriography might be a reasonable precaution.

Exploring the safety range via the transoral approach to the craniovertebral junction

Surgeries via the transoral approach are widely used to deal with lesions near the craniovertebral junction. For this approach, the pharyngeal tubercle is an important landmark to identify the midline. The foramen lacerum, another important anatomic area where some crucial structures pass, is close to the pharyngeal tubercle. In the current study, we measured relevant distances and angles on 120 adults without brain diseases to estimate the safety range of the transoral approach. Distances between the pharyngeal tubercle and the foramen lacerum were expressed as mean (SD) and 95% confidence interval. Angles between the straight lines, which pass through the pharyngeal tubercle and the foramen lacerum, and the sagittal plane, as well as the horizontal plane, were also presented as mean (SD) and 95% confidence interval. As regards the 95% confidence intervals of the angles and the distances, which were used to define the safety range, no differences were observed between the right side and the left side. During such surgeries, if the midline is defined as a datum line, it is less likely for surgeons to destroy adjacent structures when moving within 36.30 degrees on the sagittal plane and 45.00 degrees on the horizontal plane once they find the pharyngeal tubercle. It is also safe to move within 16.20 mm from the pharyngeal tubercle. With these data, we have successfully defined the safety range of the surgery, which may help operators choose proper instruments in surgery and avoid injuries to important structures. Moreover, operators may use these data to position the pharyngeal tubercle so as not to deviate from the midline.

Analysis of the dynamic relationships between the lingual artery and lingual markers in patients with obstructive sleep apnea

PURPOSE

To determine the relationships between the lingual artery and the lingual markers in tongue resting and extended positions in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) for the clinical application of functional tongue surgery.

METHOD

Computed tomography angiography (CTA) of the lingual artery was performed on 30 OSAHS patients using a 16-slice spiral CT scanner. The anatomical relationships between the lingual artery and the lingual markers were analyzed with the tongue in resting and extended positions using the CTA images.

RESULTS

The course of the lingual artery resembled the configuration of the Big Dipper constellation when the tongue was in a resting position. When the tongue was in a full-extended position, the majority of the lingual artery moved forward and upward with the hyoid and formed a "√" fashion. The positions of the tip of the greater horn of the hyoid changed with the tongue positions. While the relationship between the main lingual artery and the tip of the greater horn of the hyoid, as well as the distances between bilateral lingual arteries, remained constant in both tongue positions.

CONCLUSIONS

In conditions of dynamic tongue movement, the tip of the great horn of the hyoid and the lingual midline are constant anatomical markers to indicate the course of the lingual artery.