Constrictor Muscle Research Articles

Automated Robust Planning for IMPT in Oropharyngeal Cancer Patients Using Machine Learning

The aim of this study was to evaluate an automated treatment planning method for robustly optimized intensity modulated proton therapy (IMPT) plans for oropharyngeal carcinoma patients and to compare the results with manually optimized robust IMPT plans. An atlas regression forest based machine learning (ML) model for dose prediction was trained on CT scans, contours and dose distributions of robust IMPT plans of 88 oropharyngeal cancer patients (OCP). The ML model was combined with a robust voxel and dose volume histogram based dose mimicking optimization algorithm for 21 perturbed scenarios to generate a machine deliverable plan from the predicted dose distribution. Machine learning optimization (MLO) configuration was performed using a cross-validation approach with 3 × 8 tuning patients and comprised of adjustments to the mimicking optimization, to generate higher quality MLO plans. Independent testing of the MLO algorithm was performed with another 25 patients. Plan quality of clinical and MLO plans was evaluated by the clinical target volume (D98% voxel-wise minimum dose >94%), organ at risk (OAR) doses and the normal tissue complication probability (NTCP) (sum (Σ) of grade-2 and grade-3 dysphagia and xerostomia). Adequate robust target coverage was achieved in 24/25 clinical plans and in 23/25 MLO plans in the primary clinical target volume (CTV). In the elective CTV, 22/25 clinical plans and 24/25 MLO plans passed the robust target coverage evaluation threshold. The MLO average Σgrade 2 and Σgrade 3 NTCPs were comparable to the clinical plans (Σgrade 2 NTCPs: clinical 47.5% vs MLO 48.4%, Σgrade 3 NTCPs: clinical 11.9% vs MLO 12.3%). Significant increases in OAR average doses in MLO plans were found in the pharynx constrictor muscles (163 cGy, p=0.002) and cervical esophagus (265 cGy, p=0.002). The MLO plans were created within 45 min. This study showed that automated MLO planning is able to generate robustly optimized MLO plans with quality comparable to clinical plans in OCP.

Suspension-expansion pharyngoplasty: a modified technique for oropharyngeal collapse in obstructive sleep apnea.

Lateral pharyngeal wall (LPW) collapse plays a fundamental role in the pathogenesis of obstructive sleep apnea (OSA) and might determine the severity of the disease. This study presents the suspension/expansion pharyngoplasty (SEP) for the treatment of selected cases of OSA. The procedure aimed to splint LPW collapse via supporting and lateralization of both superior constrictor muscle (SCM) and palatopharyngeal muscle (PPM) individually and in two different planes. Twenty-one adult patients with single-level OSA who showed a lateral pattern of collapse at the oropharyngeal region had the modified procedure (SEP). The basic steps are the individual dissection of the muscular components of the lateral pharyngeal wall: SCM which was sutured anteriorly to the anterior tonsillar pillar and the PPM which was suspended to the pterygomandibular raphe. The supra-tonsillar fat was preserved. At 9-12months, highly significant improvement was reported as regards the mean Apnea hypopnea index and the mean lowest oxygen saturation (p < 0.000). The Epworth Sleepiness Scale and VAS-snoring showed a significant (p < 0.05) reduction. The oxygen desaturation index showed significant improvement. Non-significant improvements were reported as regards the percentage of total sleep time with oxygen saturation below 90%. According to Sher criteria, successful outcomes were reported in 17 patients. SEP could widen the pharyngeal airway and could support the collapsible lateral pharyngeal wall guarding against soft tissue collapse. In selected subjects, SEP had reported subjective and objective favorable outcomes with no significant comorbidities. The procedure could be combined with other procedures in multilevel surgery.

The Organs-at-Risk Dose Constraints in Head and Neck Intensity Modulated Radiation Therapy Using Data from a Multi-Institutional Clinical Trial (JCOG1015A1)

<h3>Purpose/Objective(s)</h3> The purpose of this study was to determine the organ specific dose constraints in head and neck carcinoma treated with intensity-modulated radiation therapy (IMRT) using data from a multi-institutional clinical trial (JCOG1015). <h3>Materials/Methods</h3> Dose constraints used in the JCOG1015 were as follows; Spinal cord Dmax <50 Gy, Brain Dmax <70 Gy, Brainstem Dmax <54 Gy, Optic nerve Dmax <50 Gy, Eyeball Dmax <40 Gy, Lens Dmean <6 Gy, Parotid gland Dmean <26 Gy, pharyngeal constrictor muscle (PCM) Dmean <54 Gy, Larynx Dmean <54 Gy, Inner ear Dmean <45 Gy. Brain D1cc, brainstem D1cc, and thyroid Dmean were not stated but recorded. Patient data and dose-volume histograms (DVH) of organs-at-risk (OARs) were collected from 74 patients with nasopharyngeal carcinoma treated with IMRT who enrolled in the JCOG1015 trial. The incidence of late toxicities was evaluated using the cumulative incidence method or prevalence. ROC analysis was used to estimate the optimal DVH cut-off value that predicted toxicities. <h3>Results</h3> Estimated DVH cut-off values were brainstem D1cc:55.8 Gy for G1 myelitis, brain D1cc:72.1 Gy for ≥G1 central nerve necrosis, optic nerve Dmax:53.3 Gy for G2 vision impaired, eye-ball Dmax:36.6 Gy for G2 impaired, PCM Dmean:41.2 Gy for ≥G2 dysphagia, ipsilateral inner ear Dmean:44.0 Gy for ≥G2 hearing impaired, ipsilateral inner ear Dmean:51.5 Gy for ≥G2 middle ear inflammation, and thyroid Dmean: 45.6 Gy for G1 hypothyroidism. The 3- and 5-year cumulative incidence of late toxicity by dose metrics were shown in Table 1. The estimated cut-off values were similar to dose constraints criteria used in the JCOG1015 except for PCM. In patients who received higher dose than the dose constraints in brainstem and inner ear, incidence of myelitis and hearing impaired were notably high. <h3>Conclusion</h3> The dose constraints criteria of the JCO1015 were appropriate for most OARs, although more strict dose constraints might be necessary for PCM. Dose constraints for inner ear and brainstem should be archived with higher priority.

Dosimetric Predictors of Acute and 1-Year Functional Oral Intake for Head and Neck Cancer Patients Treated with Radiotherapy

<h3>Purpose/Objective(s)</h3> In order to reduce risks of radiation-induced dysphagia after head and neck radiotherapy, a better understanding of the relationship between dose to various swallowing-related organs at risk (SOARs) is necessary. There is limited data regarding the association of 6–12-month functional swallowing outcomes and the dose to SOARs including the pharyngeal constrictor muscle (PC), cricopharyngeus (C), glottic (GL) supraglottic larynx (SGL), and the RTOG-defined Pharynx OAR (POAR). We assessed dosimetric predictors of change in swallowing function from up to 1-year post-RT. <h3>Materials/Methods</h3> We retrospectively reviewed our institutional database of patients treated with head and neck cancer from 2017-2020. Swallowing function was assessed at 1-, 3-, 6-, and 12-months post-treatment using the Functional Oral Intake Scale (FIOS, 1=no oral intake, 7=total oral intake without restrictions). Mean dose, V50, and V60 were abstracted from the treatment planning software for each SOAR. Patients were categorized by whether clinically relevant constraint parameters were met for each SOAR, which were then evaluated for association with FOIS using the Wilcoxon test. <h3>Results</h3> In total, 141 patients with evaluable treatment plans and swallowing outcomes were analyzed. Of the patients included for analysis, 51% had oropharyngeal cancer, 100% received concurrent chemotherapy, and 31% were treated post-operatively. Across all included treatment plans, the median prescribed dose to PTV was 70 Gy (38-70 Gy). Swallowing outcomes at 1-, 3-, 6-, and 12-months post-treatment were available for 132 (94%), 129 (91%), 121 (86%), and 111 (79%) patients, respectively. The median (range) FOIS scores at baseline, 1-, 3, 6-, and 12-months were 7 (5-7), 4 (2-7), 6 (3-7), and 7 (6-7). For each swallowing structure the mean (Gy) doses (listed as median (IQR)) were: 57.7 (49.0-64.3) for PC, 47.3 (38.7-51.4) for C, 38.9 (33.6-43.4) for GL, 47.4 (38.8-52.2) for SGL, and 53.2 (45.4-59.5) for POAR. The V50 (%) for each SOAR was: 77.5% (52.6-93.5) for PC, 23.3% (5.1-59.8) for C, 0.2% (0-5.1) for GL, 36.4% (19.5-48.5) for SGL, and 67.3% (42.8-86.6) for POAR. The V60 (%) for each SOAR was: 47.5% (23.0-75.5) for PC, 0.5% (0-8.6) for C, 0% (0-0) for GL, 21.4% (4.2-34.5) for SGL, and 32.2% (8.3-55.7) for POAR. On dosimetric analysis, PC mean≤50Gy, POAR mean≤45Gy, and POAR V50<33% were associated with increased FOIS at 1- and 3-months (p<0.05). POAR V60<15% and SGL mean<=40Gy was associated with FOIS at 1-mo (p<0.05). No evaluated factors were associated with 6- or 12-month FOIS. <h3>Conclusion</h3> Lower doses of radiation to pharyngeal constrictor, RTOG-defined pharynx, and supraglottic larynx are associated with improved swallowing function in patients with head and neck cancer. Radiation treatment plans should be optimized to reduce dose to these structures in order to improve acute swallowing outcomes. A larger sample size is needed to better evaluate the impact of radiation dose to these structures on long term swallowing outcomes.

We are One: An Investigation of Bias in Deep Learning Autocontouring

<h3>Purpose/Objective(s)</h3> Deep Learning based Autocontouring (DLC) has demonstrated consistent and accurate organ delineation, leading to time-savings in clinical contouring. Data used in development and testing of DLC algorithms have been largely sourced from single geographic populations, which leads to a potential risk of population-based bias being learnt by the algorithms. The goal of this study is to evaluate this risk by determining the impact ethnicity and or differing geographic populations have on performance of an autocontouring system. <h3>Materials/Methods</h3> 40 Head Neck CT scans were collected from four clinics, located in Europe (n=2) and Asia (n=2). A single observer manually delineated 15 organs-at-risk (OAR) in every dataset. A DLC solution then processed all CTs to produce 15 OARs. The autocontoured OARs were compared to the manual delineations using 3D Dice Similarity Coefficient (3D DSC), Added Path Length (APL) and 2D 95% Hausdorff Distance measures (2D 95% HD). The null hypothesis was that quantitative performance on all populations is the same. A Kruskall-Wallis test (KWT) was performed per similarity measure and per organ was used to test this hypothesis for the four sites. <h3>Results</h3> The KWT test found no statistically significant difference for the majority of structures across all similarity metrics. With a Bonferroni Correction applied to reduce this risk of Type I error with multiple tests, all structures showed no statistically significant difference across the populations except the Pharyngeal Constrictor Muscle. <h3>Conclusion</h3> No statistically significant differences in performance of deep learning contouring across populations were found for most structures. From this study, there appears to be no bias across populations, demonstrating its relevance internationally. This investigation of potential geographic or ethnic bias should extend to more patients, populations and anatomical regions in future.

Bilateral Peritonsillar Abscess-Developed Ruptured Meckel's Diverticulum

Peritonsillar abscess (PTA) is an accumulation of pus between the fibrous capsule of the palatine tonsils and the superior pharyngeal constrictor muscle. Bilateral PTA (BPTA) is a rare disease. Meckel's diverticulum (MD) is a congenital abnormality of the distal ileum associated with failed vitelline duct closure. Spontaneous MD rupture during the management of PTA never happened before. In this article, the authors present a case of BPTA-developed MD rupture. We present a case involving an 18-year-old male who presented to the emergency department (ED) for a 2-day history of worsening sore throat, trismus, fever, and odynophagia; a diagnosis of bilateral severe PTA was made. During the management of the BPTA, the patient developed severe acute abdominal pain which was diagnosed later as a case of MD rupture. In ED, the patient underwent computerized tomography (CT) scan of the neck that showed bilateral hypodense masses, consistent with BPTA. Conservative management was started on IV antibiotics, IV fluids, and IV analgesia at the time of diagnosis in the ED. The patient then underwent two attempts of needle aspiration using 18-gauge needles that showed evidence of aspirated pus. Later on, the patient developed severe abdominal pain, which is evaluated by the general surgery department (GS), and underwent ultrasonography (US) and CT scan; then, the diagnosis of rupture MD was made. The patient underwent diagnostic laparoscopy performed by the GS team and improved thereafter. In this article, the authors present a case of BPTA-developed MD rupture.

Endoscopic Treatment of Zenker's Diverticulum. A Review of The Literature

Zenker's diverticulum (ZD) is a sac-like evagination of the mucosa and submucosa through the Killian triangle, an area of muscle weakness between the transverse fibers of the cricopharyngeal muscle and the oblique fibers of the inferior inferior constrictor muscle. The reported prevalence of ZD is between 0.01 and 0.11 percent. The Killian triangle is more frequent in men than in women (60 versus 34 percent). The definitive treatment of symptomatic ZD is surgical. The treatment must be individualized for each case, likewise, the doctor must adopt the one in which he feels most comfortable and as there is more experience in the center in which it is performed, taking into account the technique and the adequate management of complications.

Scope of Homoeopathy in Peritonsillar Abscess

A Peritonsillar abscess is also known as Quinsy. It is an accumulation of pus behind the palatine tonsil due to an infection. Precisely, it is a collection of pus between the fibrous capsule of the tonsil, usually at the upper pole &amp; the superior constrictor muscles of pharynx. The signs &amp; symptoms of quinsy include fever, throat pain, trouble in opening mouth, redness, swelling and change in the voice. Pain is usually worse on one side. The complications may include blockage of the airway or aspiration pneumonitis. The conventional treatment is done for removing the pus by incision &amp; drainage along with medications for swelling &amp; pain management. The homeopathic line of treatment depends on the actual state of the condition. Homeopathic medicines can be used in mild to moderate cases of peritonsillar abscess successfully as see through this research study. In this study, 46 cases of peritonsillar abscess of age group between 5 to 80 years were included. After going through the results, it is observed that the peritonsillar abscess can be treated successfully by Homoeopathy. The scope of Homoeopathy in the treatment of peritonsillar abscess is excellent and shows high success rate of 44 out of 46 patients responding successfully to the Homoeopathic treatment with no signs of recurrence in near future. The outstanding Homoeopathic remedies in the treatment of peritonsillar abscess were found to be mostly Hepar Sulph &amp; Merc Sol along with Calc Carb, Baryta Carb and Phytolacca. All that is required in the treatment of peritonsillar abscess is quick selection of right remedy and right dose for the instant relief rationally. Hence we can rightly claim that by proper Homoeopathic treatment we can make the world better for the future generation. This research paper will certainly help the health professionals to overcome such problems of surgical cases and consider the benefits of the facts in scope of Homoeopathy in peritonsillar abscess.

Videofluorographic Analysis of Swallowing Function after Total Glossolaryngectomy.

Surgeons have traditionally believed that swallowing is mainly dependent on gravity after total glossolaryngectomy. However, swallowing function after total glossolaryngectomy varies widely among patients, and a thorough analysis is lacking. The authors aimed to clarify the swallowing function after total glossolaryngectomy and determine whether it is primarily dependent on gravity. The authors retrospectively analyzed videofluorographic examinations of patients who underwent total glossolaryngectomy and free or pedicle flap reconstruction. The authors enrolled 20 patients (12 male; mean age, 61 years; age range, 43 to 89 years). All patients demonstrated constriction of the reconstructed pharynx to some degree, and no patient's ability to swallow was dependent on gravity alone. Videofluorography showed excellent barium clearance in eight patients and poor clearance in 12. All patients with excellent clearance showed strong constriction of the posterior pharyngeal wall, whereas only 8.3 percent of the patients with poor clearance showed adequate constriction, which was significantly different ( p = 0.0007). Velopharyngeal closure and lip closure also contributed significantly to excellent clearance ( p = 0.041). The shape of the reconstructed pharynx (depressed, flat, protuberant) showed no statistically significant association with excellent clearance. Contrary to previous understanding, constriction of the remnant posterior pharyngeal wall played an important role in swallowing after total glossolaryngectomy, and gravity played a secondary role. Dynamic posterior pharyngeal wall movement might result from the increased power of the pharyngeal constrictor muscle and compensate for the immobility of the transferred flap. A well-functioning pharyngeal constrictor muscle and complete velopharyngeal and lip closures can contribute to excellent barium clearance in patients after total glossolaryngectomy. Therapeutic, III.

Case Report: Bilateral peritonsillar abscess with complications of upper airway obstruction

Background: Peritonsillar abscess is a collection of pus between the tonsillar fibrous capsule and the pharyngeal constrictor muscle. Unilateral peritonsillar abscess is a common complication of acute tonsillitis, whereas bilateral peritonsillar abscess is rare. The incidence of bilateral peritonsillar abscess remains unknown but is estimated to be 4.9% of all peritonsillar abscess cases. Case report: A 20-year-old man came to the emergency room with bilateral peritonsillar abscess and complained of shortness of breath for two weeks. Physical examination showed muffled voice, 82% oxygen saturation, and inspiratory stridor. The isthmus faucium was narrow, with approximately 30% remaining. Peritonsillar puncture revealed pus mixed with blood. The treatment for this patient included bilateral peritonsillar incision and drainage and intravenous antibiotics of levofloxacin and metronidazole. The patient came to the Ear, Nose, Throat, Head, and Neck (ENTHN) Outpatient Unit eight days after the procedure for a control checkup and was in good condition. Conclusion: We have reported a bilateral peritonsillar abscess with complications of upper airway obstruction, in which we performed incision and drainage. Prompt and appropriate management is needed to avoid unwanted morbidity and mortality.

Organs-at-risk dose constraints in head and neck intensity-modulated radiation therapy using a dataset from a multi-institutional clinical trial (JCOG1015A1)

BackgroundJCOG1015A1 is an ancillary research study to determine the organ-specific dose constraints in head and neck carcinoma treated with intensity-modulated radiation therapy (IMRT) using data from JCOG1015.MethodsIndividual patient data and dose-volume histograms of organs at risk (OAR) were collected from 74 patients with nasopharyngeal carcinoma treated with IMRT who enrolled in JCOG1015. The incidence of late toxicities was evaluated using the cumulative incidence method or prevalence proportion. ROC analysis was used to estimate the optimal DVH cut-off value that predicted toxicities.ResultsThe 5-year cumulative incidences of Grade (G) 1 myelitis, ≥ G1 central nervous system (CNS) necrosis, G2 optic nerve disorder, ≥ G2 dysphagia, ≥ G2 laryngeal edema, ≥ G2 hearing impaired, ≥ G2 middle ear inflammation, and ≥ G1 hypothyroidism were 10%, 5%, 2%, 11%, 5%, 26%, 34%, and 34%, respectively. Significant associations between DVH parameters and incidences of toxicities were observed in the brainstem for myelitis (D1cc ≥ 55.8 Gy), in the brain for CNS necrosis (D1cc ≥ 72.1 Gy), in the eyeball for optic nerve disorder (Dmax ≥ 36.6 Gy), and in the ipsilateral inner ear for hearing impaired (Dmean ≥ 44 Gy). The optic nerve, pharyngeal constrictor muscle (PCM), and thyroid showed tendencies between DVH parameters and toxicity incidence. The prevalence proportion of G2 xerostomia at 2 years was 17 versus 6% (contralateral parotid gland Dmean ≥ 25.8 Gy vs less).ConclusionsThe dose constraint criteria were appropriate for most OAR in this study, although more strict dose constraints might be necessary for the inner ear, PCM, and brainstem.

Novel Strategies for Managing Retropharyngeal Lymph Node Metastases in Head and Neck and Thyroid Cancer with Transoral Robotic Surgery (TORS).

Retropharyngeal metastases are encountered in a variety of head and neck malignancies, imposing significant surgical challenges owing to their distinct location and proximity to neurovascular structures. Radiotherapy is the recommended treatment in most cases owing to its oncological efficacy. However, retropharyngeal irradiation affects the superior pharyngeal constrictor muscles and parotid glands, with the potential for long-term dysphagia and xerostomia. A younger oropharyngeal and thyroid cancer patient demographic is trending, fueling interest in treatment de-escalation strategies. Consequently, reducing radiotoxicity and its long-term effects is of special relevance in modern head and neck oncology practice. Through its unique ability to safely extirpate these traditionally difficult-to-access retropharyngeal lymph nodes via a natural orifice, TransOral Robotic Surgery (TORS) can considerably lower the surgical morbidity of retropharyngeal lymph node dissection (RPLND), compared with current existing approaches. This review summarizes the latest developments in the field, exposing current research gaps and discusses specific clinical settings where TORS could enable treatment de-escalation. In early-stage node-negative oropharyngeal cancer, single-modality surgical treatment with TORS RPLND may improve risk stratification of metastasis and recurrence in this region. TORS RPLND is also a potentially viable treatment option in salvage of an isolated retropharyngeal node recurrence or in the primary setting of a thyroid malignancy with a single positive retropharyngeal node. In time, TORS RPLND may provide an alternative de-escalation strategy in these three scenarios. However, with the reported morbidities, further prospective trials with long-term follow-up data are required to prove oncological safety and functional benefits over existing strategies.

Laryngeal and swallow dysregulation following acute cervical spinal cord injury.

Laryngeal function is vital to airway protection. Although swallow is mediated by the brainstem, the mechanism underlying the increased risk of dysphagia after cervical spinal cord injury (SCI) is unknown. We hypothesized that: 1) loss of descending phrenic drive affects swallow and breathing differently, and 2) loss of ascending spinal afferent information alters swallow regulation. We recorded electromyograms (EMGs) from upper airway and chest wall muscles in freely breathing pentobarbital-anesthetized cats and rats. Laryngeal abductor activity during inspiration increased about twofold following C2 lateral hemisection. Ipsilateral to the injury, the crural diaphragm EMG amplitude was reduced during breathing (62 ± 25% change postinjury), but no animal had complete termination of activity; 75% of animals had increased contralateral diaphragm recruitment, but this did not reach significance. During swallow, laryngeal adductor and pharyngeal constrictor muscles increased activity, and diaphragm activity was bilaterally suppressed. This was unexpected because of the ipsilateral-specific response during breathing. Swallow-breathing coordination was disrupted by injury, and more swallows occurred during early expiration. Finally, to determine if the chest wall is a major source of feedback for laryngeal regulation, we performed T1 total transections in rats. As in the C2 lateral hemisection, inspiratory laryngeal recruitment was the first feature noted after injury. In contrast to the C2 lateral hemisection, diaphragmatic drive increased after T1 transection. Overall, we found that SCI alters laryngeal drive during swallow and breathing, and alters swallow-related diaphragm activity. Our results show behavior-specific effects, suggesting that swallow is affected more than breathing is by SCI, and emphasizing the need for additional studies on the effect of ascending afferents from the spinal cord on laryngeal function.NEW & NOTEWORTHY This is the first manuscript to determine the impact of cSCI on laryngeal and swallow function, and to describe a possible mechanism for dysphagia and altered airway protection after injury.

Comparison of Dosimetric Parameters in Dysphagia Aspiration-Related Structures and Clinical Correlation in Head and Neck Cancer Patients Treated With Radiotherapy.

IntroductionChemoradiotherapy plays a major role in the treatment of head and neck cancer (HNC). Persistent dysphagia following primary chemoradiotherapy for head and neck cancers can have a devastating effect on a patient’s quality of life. Many studies have shown that the dosimetric sparing of critical structures which were included in swallowing such as the pharyngeal constrictor muscle and larynx can provide improved functional outcomes and better quality of life. However, there are no current randomized studies confirming the benefits of such swallowing-sparing strategies. The aim is to evaluate late dysphagia after chemoradiotherapy for head and neck cancer and to examine its correlation with clinical and dosimetric parameters.Materials and methodsThe period of this prospective study was from November 2018 to March 2020. Patients were divided randomly in 1:1 ratio into two groups, group 1 and group 2, each with 25 patients. Group 1 was planned by three-dimensional conformal radiotherapy (3D-CRT) technique and group 2 was planned by intensity-modulated radiotherapy technique (IMRT) technique. Treatment was delivered after approval of radiotherapy plan. To evaluate the dose to dysphagia aspiration-related structures (DARS), these structures were contoured and dose-volume histograms were generated. Various dosimetric parameters of DARS were evaluated. Swallowing status was clinically evaluated based on the Radiation Therapy Oncology Group and the Common Terminology Criteria for Adverse Events, version 5.ResultsA significant advantage was seen with intensity-modulated radiotherapy technique (IMRT) in comparison to three-dimensional conformal radiotherapy (3D-CRT) in terms of mean dose delivered to the pharyngeal constrictor muscles (66.03 Gy vs 68.77 Gy, p=0.003). The mean dose delivered to the combined dysphagia/aspiration-related structures (DARS) was statistically significantly lower in IMRT compared to 3D-CRT (66.15 Gy vs. 70.09 Gy, p<0.001). Other dose-volumes were also reduced in IMRT group (V30: {98.64% vs. 99.88%, p=0.05}; V50: {90.49% vs. 99.02%, p=0.0002}; V60: {83.92% vs. 95.04, p=0.0002}; D50: {70 Gy vs. 71.16 Gy, p=0.001); and D80: {61.18 Gy vs. 67.39 Gy, p=0.01}. Futhermore, the clinical worsening of dysphagia was less common in IMRT group (48% vs. 80%, p=0.039).ConclusionIMRT can reduce the high-dose volumes received by the DARS receiving high doses by sparing these structures through optimization. This may provide a significant additional benefit that could improve dysphagia and hence the quality of life of patients with head and neck cancer.

Fiberoptic laryngoscopic neurological examination of amyotrophic lateral sclerosis patients with bulbar symptoms

ObjectiveBulbar symptoms in amyotrophic lateral sclerosis (ALS) are variable, reflecting bulbar and pseudobulbar palsy. The current study sought to characterize the pharyngeal findings in ALS using a fiberoptic laryngoscope and compare them with the findings of general neurological examination. MethodsWe enrolled ALS patients with bulbar symptoms who were admitted between 2014 and 2020. All participants were evaluated on salivary status, velopharyngeal movement during speech and swallowing, pharyngeal constriction, and vocal cord movement using fiberoptic laryngoscopy. The laryngoscopic findings were compared with general neurological examination results. ResultsA total of 50 patients (31 men; median age: 69 years) were enrolled. Salivary residue in the hypopharynx was the most common abnormal finding on laryngoscopy (40 patients; 80%). Twenty-three patients (46%) exhibited velopharyngeal insufficiency, 18 of which exhibited good velopharyngeal closure in swallowing and poor velopharyngeal closure in speech. Thus, these patients presented speech-swallow dissociation (SSD) in velopharyngeal closure. Five patients (10%) exhibited unilateral weakness of the pharyngeal constrictor muscles in phonation. Compared with general neurological examinations, emotional incontinence was more frequent in patients who presented with SSD in velopharyngeal movement, compared with those who did not. None of the five patients with unilateral weakness of pharyngeal constriction showed curtain movement on examination via the mouth. ConclusionThe specific findings of laryngoscopy in ALS patients, such as SSD in velopharyngeal closure and laterality in pharyngeal constriction, could not be evaluated by general neurological examination via the mouth.

Intraoperative Management of the Recurrent Laryngeal Nerve Transected or Invaded by Thyroid Cancer.

Thyroid cancer often invades the recurrent laryngeal nerve (RLN), causing vocal cord paralysis. In such patients, the invaded portion of the RLN usually needs to be resected through curative surgery. We attempt to preserve the nerve by performing sharp dissection in such cases. During nerve dissection, an intraoperative nerve monitoring system helps identify the course of the RLN in the fibrous tissue around the tumor or even within the tumor, and also helps evaluate the nerve integrity. Because of extensive dissection, the preserved RLN may become much thinner than its original thickness. We refer to this procedure as “partial layer resection” of the RLN. In our cases, although the dissected RLNs became thinner, we found that vocal cord function recovered in most patients. If the RLN is fully involved by thyroid cancer or response of the vocal cord against electric stimulation to the RLN is lost, we resect the portion of the RLN together with the tumor and repair it using one of the reconstruction techniques. When a unilateral RLN is resected, the vocal cord on that side is paralyzed. Symptoms include hoarseness, mis-swallowing, and short phonation. RLN reconstruction using one of the reconstruction techniques leads to the recovery of phonatory and swallowing function, although the normal motion of the vocal cord on the side of the anastomosis is not restored. We used direct anastomosis, free nerve grafting, ansa cervicalis-RLN anastomosis, and vagus-RLN anastomosis to reconstruct the RLN. Thyroid cancer often invades the RLN near the Berry’s ligament. In such patients, surgeons might assume that reconstruction of the RLN may not be possible because the peripheral stump of the RLN cannot be observed. However, if we divide the inferior pharyngeal constrictor muscles along the lateral edge of the thyroid cartilage, the peripheral RLN can be identified, and nerve reconstruction can be performed. We refer to this procedure as “laryngeal approach”.In summary, of the patients with thyroid cancer who required resection of the RLN, RLN reconstruction led to the recovery of phonatory function. We suggest that all thyroid surgeons familiarize themselves with these reconstruction techniques.

Quality of life and two-year results of a randomized phase III study of dysphagia-optimized intensity modulated radiotherapy (DO-IMRT) versus standard IMRT (S-IMRT) in head and neck cancer.

6065 Background: Most newly diagnosed oro- &amp; hypopharngeal cancers (OPC, HPC) are treated with (chemo)RT with curative intent but at the consequence of adverse effects on quality of life. We investigated if using DO-IMRT to reduce RT dose to the dysphagia/aspiration related structures (DARS) improved swallowing function compared to S-IMRT. Methods: Patients with T1-4, N0-3, M0 OPC/HPC were randomised 1:1 to S-IMRT (65 Gray (Gy)/30 fractions (f) to primary &amp; nodal tumour; 54Gy/30f to remaining pharyngeal subsite &amp; nodal areas at risk of microscopic disease) or DO-IMRT. The volume of the superior &amp; middle pharyngeal constrictor muscle (PCM) (OPC) or inferior PCM (HPC) lying outside the high-dose target volume was set a mandatory mean dose constraint in DO-IMRT. Treatment allocation was by minimisation balanced by centre, use of induction/concomitant chemotherapy, tumour site &amp; AJCC stage. Primary endpoint was mean MD Anderson Dysphagia Inventory (MDADI) composite score 12 months after RT. Secondary endpoints included University of Washington (UW)-Qol, Performance Status Scale Head &amp; Neck (PSS-HN) domain scores (range: 0-100), swallow volume, swallow capacity and local control. Results: 112 patients (56 S-IMRT, 56 DO-IMRT) were randomised from 22 UK &amp; Ireland centres from 06/2016 - 04/2018. 111/112 had RT doses as prescribed (1 patient died before RT). Outcome measures at 12 and 24 months are summarised below. DO-IMRT had higher MDADI scores at 12 (p = 0.04) and 24 (p = 0.07) months. Clinically important improvements in swallowing function were seen in patients receiving DO-IMRT using PSS-HN domains and the UW-QoL tool. Conclusions: DO-IMRT improved patient reported swallowing function compared with S-IMRT. Improvements were seen in overall MDADI as well as functional scores in both PSS-HN and UW-QoL. Clinical trial information: 25458988. [Table: see text]

Case Report: Bilateral peritonsillar abscess with complications of upper airway obstruction

Background: Peritonsillar abscess is a collection of pus between the tonsillar fibrous capsule and the pharyngeal constrictor muscle. Unilateral peritonsillar abscess is a common complication of acute tonsillitis, whereas bilateral peritonsillar abscess is rare. The incidence of bilateral peritonsillar abscess remains unknown but is estimated to be 4.9% of all peritonsillar abscess cases. Case report: A 20-year-old man came to the emergency room with bilateral peritonsillar abscess and complaining of shortness of breath for two weeks. Physical examination showed muffled voice, 82% oxygen saturation, and inspiratory stridor. The isthmus faucium was narrow, with approximately 30% remaining. Peritonsillar puncture revealed pus mixed with blood. The treatment for this patient included bilateral peritonsillar incision and drainage and intravenous antibiotics of levofloxacin and metronidazole. The patient came to the Ear, Nose, Throat, Head, and Neck (ENTHN) Outpatient Unit eight days after the procedure for a control checkup and was in good condition. Conclusion: We have reported a bilateral peritonsillar abscess with complications of upper airway obstruction, in which we performed incision and drainage. Prompt and appropriate management is needed to avoid unwanted morbidity and mortality.

Predicting acute severe toxicity for head and neck squamous cell carcinomas by combining dosimetry with a radiosensitivity biomarker: a pilot study.

Radiotherapy (RT) against head and neck squamous cell carcinomas (HNSCC) may lead to severe toxicity in 30-40% of patients. The normal tissue complication probability (NTCP) models, based on dosimetric data refined the normal tissue dose/volume tolerance guidelines. In parallel, the radiation-induced nucleoshuttling (RIANS) of the Ataxia-Telangiectasia Mutated protein (pATM) is a predictive approach of individual intrinsic radiosensitivity. Here, we combined NTCP with RADIODTECT©, a blood assay derived from the RIANS model, to predict RT toxicity in HNSCC patients. RADIODTECT© cutoff values (i.e. 57.8 ng/mL for grade⩾2 toxicity and 46 ng/mL for grade⩾3 toxicity) have been previously assessed. Validation was performed on a prospective cohort of 36 HNSCC patients treated with postoperative RT. Toxicity was graded with the Common Terminology Criteria for Adverse Events (CTCAE) scale and two criteria were considered: grade⩾2 oral mucositis (OM2), grade⩾3 mucositis (OM3) and grade⩾2 dysphagia (DY2), grade⩾3 dysphagia (DY3). pATM quantification was assessed in lymphocytes of HNSCC patients. The discrimination power of the pATM assay was evaluated through the Area Under the Receiver Operator Characteristics Curve (AUC-ROC). Two previously described NTCP models were considered, including the dose to the oral cavity and the mean dose to the parotid glands (OM2 and OM3) and the dose to the oral cavity, to the larynx and the volume of pharyngeal constrictor muscles (DY2 and DY3). Combining NTCP models with RADIODTECT© blood test improved the AUC-ROC. Considering the prediction of mucositis, AUC-ROCNTCP+RADIODTECT©=0.80 was for OM2, and AUC-ROCNTCP+RADIODTECT©=0.78 for OM3. Considering the prediction of acute dysphagia, AUC-ROCNTCP+RADIODTECT©=0.71 for DY2 and for DY3. Combining NTCP models with a radiosensitivity biomarker might significantly improve the prediction of toxicities for HNSCC patients.

Rapid Intravenous Injection of Fentanyl (FNT) Causes a Vagal‐Mediated Lethal Sudden Ventilatory Arrest in Anesthetized Rats

Opioids have been used for analgesia and anesthesia mainly via activation of central opioid mu‐receptors (MORs). It also causes overdose deaths due to ventilatory failure, in which FNT is the deadest. Rapid intravenous (IV) injection of overdose FNT triggers a sudden death within a few minutes or even seconds, but the relevant mechanism remains unclear. Because bolus IV injection of FNT at a low dose produced a vagal‐mediated brief apnea (Zhuang et al, AJP 2012), This study was aimed to characterize the cardiorespiratory disorders responsible for the sudden death and determine the vagal role in generating the lethal ventilatory arrest. EMGs of external and internal intercostal (EMGEI and EMGII), thyroarytenoid and superior pharyngeal constrictor muscles (EMGTA and EMGSPC) were simultaneously recorded before and after IV injection of FNT in the anesthetized vagal intact and vagotomized rats. The optical fiber scope of an oral video camera was applied to visualize the vocal and pharyngeal responses. Immunohistochemical approach was used to define the presence of MOR expression in the pulmonary vagal sensory neurons retrogradely labeled by DiI. FNT induced an apnea or a lethal ventilatory arrest in a dose‐dependent manner associated with hypotension and bradycardia. The apnea/ventilatory arrest was characterized by silence of EMGEI with tonic discharges of EMGII, EMGTA, and EMGSPC, i.e., the central apnea (expiratory) coupled with vocal closure and pharyngeal constriction/collapse and chest wall rigidity (triple‐apnea). Vagotomy abolished the evoked cardiorespiratory responses. MOR expression in vagal pulmonary neurons, especially C‐neurons of the nodose and jugular ganglia. Our results suggest that rapid IV injection of FNT at a high dose uniquely causes a vagal‐mediated triple‐apnea, leading to the sudden death in anesthetized rats.