Functional Swallowing Units (FSUs) as organs-at-risk for radiotherapy. PART 1: Physiology and anatomy

Subtotal glossectomy with conservation of the hyo-styloglossus unit (HSU): a new pivotal concept for preserving tongue function in extended glossectomy

Objective

The local spread of oral tongue squamous cell carcinoma (OTSCC) follows pathways of dissemination along areas of lesser resistance. In more advanced scenarios, the tumor can extend beyond the hemi-tongue of origin, by passing through the lingual septum and following the fibers of the transverse muscle. This can lead to the invasion of the contralateral extrinsic muscles, the first being the genioglossus and more laterally the hyoglossus. An anatomically guided surgical resection of the tumor can be planned to ensure both oncological safety and an acceptable functional outcome. This approach aims to preserve the hyo-styloglossus unit (HSU) whenever feasible.

Methods

Between January 2019 and November 2022, six patients received extended glossectomy Type B (EG Type B), with preservation of the HSU. Preliminary oncological results and functional results in terms of swallowing (FOIS score) and quality of life (MDADI) are presented.

Results

Five out of the six patients are alive and disease-free, while one patient died due to other causes. All patients who were candidates for an EG Type B underwent a swallowing assessment prior to surgery and followed daily postoperative swallowing training. At discharge, the patients continued swallowing training in an outpatient clinic. Five out of the six patients reached a full oral diet within 1 year of follow-up.

Conclusion

The oncological results confirm the safety of this technique. The importance of preserving the HSU, the minimal functional unit, shows very encouraging results in terms of swallowing rehabilitation.

Post-operative intensity-modulated vs 3D conformal radiotherapy after conservative surgery for laryngeal tumours of the supraglottic region: a dosimetric analysis on 20 patients

Objective

To perform a dosimetric comparison between intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy in patients with locally advanced (stage III and IV) tumours of the supraglottic region treated with conservative surgery and post-operative radiotherapy.

Methods

An in-silico plan using a 3D conformal shrinking field technique was retrospectively produced for 20 patients and compared with actually delivered IMRT plans. Eighteen structures (arytenoids, constrictor muscles, base of tongue, floor of mouth, pharyngeal axis, oral cavity, submandibular glands and muscles of the swallowing functional units [SFU]) were considered.

Results

IMRT allowed a reduction of maximum and mean doses to 9 and 14 structures, respectively (p < .05).

Conclusions

IMRT achieved a reduction of unnecessary dose to the remnant larynx and the majority of surrounding SFUs. Further prospective analyses and correlations with functional clinical outcomes are required to confirm these dosimetric findings.

Using Sequence Analyses to Quantitatively Measure Oropharyngeal Swallowing Temporality in Point-of-Care Ultrasound Examinations: A Pilot Study

(1) Background: Swallowing is a complex process that comprises well-timed control of oropharyngeal and laryngeal structures to achieve airway protection and swallowing efficiency. To understand its temporality, previous research adopted adherence measures and revealed obligatory pairs in healthy swallows and the effect of aging and bolus type on the variability of event timing and order. This study aimed to (i) propose a systemic conceptualization of swallowing physiology, (ii) apply sequence analyses, a set of information-theoretic and bioinformatic methods, to quantify and characterize swallowing temporality, and (iii) investigate the effect of aging and dysphagia on the quantified variables using sequence analyses measures. (2) Method: Forty-three participants (17 young adults, 15 older adults, and 11 dysphagic adults) underwent B-mode ultrasound swallowing examinations at the mid-sagittal plane of the submental region. The onset, maximum, and offset states of hyoid bone displacement, geniohyoid muscle contraction, and tongue base retraction were identified and sorted to form sequences which were analyzed using an inventory of sequence analytic techniques; namely, overlap coefficients, Shannon entropy, and longest common subsequence algorithms. (3) Results: The concurrency of movement sequence was found to be significantly impacted by aging and dysphagia. Swallowing sequence variability was also found to be reduced with age and the presence of dysphagia (H(2) = 52.253, p < 0.001, η2 = 0.260). Four obligatory sequences were identified, and high adherence was also indicated in two previously reported pairs. These results provided preliminary support for the validity of sequence analyses for quantifying swallowing sequence temporality. (4) Conclusions: A systemic conceptualization of human deglutition permits a multi-level quantitative analysis of swallowing physiology. Sequence analyses are a set of promising quantitative measurement techniques for point-of-care ultrasound (POCUS) swallowing examinations and outcome measures for swallowing rehabilitation and evaluation of associated physiological conditions, such as sarcopenia. Findings in the current study revealed physiological differences among healthy young, healthy older, and dysphagic adults. They also helped lay the groundwork for future AI-assisted dysphagia assessment and outcome measures using POCUSs. Arguably, the proposed conceptualization and analyses are also modality-independent measures that can potentially be generalized for other instrumental swallowing assessment modalities.

A modified pull-through approach with a pedicled bone flap for oral and oropharyngeal cancer resection: a feasibility study

PURPOSE

Compromised swallowing, speaking, and local complications are the major disadvantages of established approaches to the posterior tongue and oropharynx. The mandibular split involves an esthetically unpleasant bipartition of the lower lip and is prone to bony non-union or sequestration. The conventional pull-through technique on the other hand lacks the secure reattachment of the lingually released soft tissues.

METHODS

The feasibility of a new modified pull-through approach was tested on three anatomical specimens. CAD/CAM cutting guides were used to design a retentive bone flap to properly refixate the genioglossus and geniohyoid muscles after the procedure. The radiographic assessment and treatment planning was performed on 12 cadavers. The entire procedure was tested surgically via dissection in three of those cases. This procedure was then applied in a clinical case.

RESULTS

Precise repositioning and dynamic compression of bony segments was possible reproducibly and without injury to adjacent structures. In all dissected cases, a median lingual foramen was found and in two cases vessels entering it could be dissected Radiologic anatomical landmarks were sufficient in all 12 cases to perform the clinical planning procedure. Clinically, the osteotomized segment demonstrated good blood supply and plateless repositioning was verified postoperatively via cone beam scan.

CONCLUSION

The method presented is safe and easy to perform. Individual cutting guides improve the safety and accuracy of the procedure, potentially eliminating the need for osteosynthesis. We provide the anatomical and radiologic basis for clinical evaluation of this pedicled bone flap procedure and present the clinical application of this modified pull-through approach.

Beyond the boundaries of compartmental hemiglossectomy: a proposal for an anatomically based classification of surgical approaches to advanced oral tongue squamous cell carcinoma

INTRODUCTION

In the last decade, compartmental surgery (CTS) has been the surgical approach of choice for advanced tumors of the tongue and oral floor.

METHODS

Advanced tumors (cT3-T4) oral tongue squamous cell carcinoma (OTSCC) may extend beyond the lingual septum and involve the contralateral hemitongue, developing along the intrinsic transverse muscle. The disease may then involve the genioglossus muscle and, more laterally, the hyoglossus muscle.

RESULTS

The surgical approach to the contralateral tongue must be guided by anatomic and anatomopathological principles to achieve a safe oncological resection based on the principles of CTS.

CONCLUSION

We propose a schematic classification of glossectomies that extend to the contralateral hemitongue based on the anatomy and pathways of tumor spread.

Evaluation of morphological features of palatopharyngeus insertion into the thyroid cartilage

The attachment of the palatopharyngeus extended from the posterior end of the thyroid cartilage to the posterior margin of the inferior constrictor attachment that might contribute to successive swallowing movements. Laryngeal elevation is essential for proper swallowing and breathing. Recently, clinical research has demonstrated that the palatopharyngeus, a longitudinal muscle of the pharynx, is involved in the elevation of the larynx. However, the morphological relationship between the larynx and palatopharyngeus remains unclear. In the present study, we analyzed the attachment site and characteristics of the palatopharyngeus in the thyroid cartilage. We evaluated 14 halves of seven heads from Japanese cadavers (average age: 76.4 years); 12 halves, anatomically and two halves histologically. A part of the palatopharyngeus, which originated from the inferior aspect of the palatine aponeurosis, was attached to the inner and outer surfaces of the thyroid cartilage through collagen fibers. The attachment area extends from the posterior end of the thyroid cartilage to the posterior margin of the attachment site of the inferior constrictor. The palatopharyngeus may elevate the larynx with the suprahyoid muscles and contribute to successive movements of swallowing with surrounding muscles. Based on our findings and previous studies, palatopharyngeus with various muscle bundle directions may be essential for the coordination of continuous swallowing events.

Quantification of the Swallowing Mechanism Through Muscle Synergy Analysis

Decreased swallowing function increases the risk of choking and aspiration pneumonia. Videofluoroscopy and computed tomography allow for detailed observation of the swallowing movements but have radiation risks. Therefore, we developed a method using surface electromyography (sEMG) to noninvasively assess swallowing function without radiation exposure. A 44-channel flexible sEMG sensor was used to measure the sEMG signals of the hyoid muscles during swallowing in 14 healthy young adult and 14 elderly subjects. Muscle synergy analysis was performed to extract the muscle synergies from the sEMG signals, and the three synergies were extracted from the hyoid muscle activities during the swallowing experiments. The experimental results showed that the three synergies represent the oral, early pharyngeal, and late pharyngeal swallowing phases and that swallowing strength is tuned by the strength of the muscle activities, whereas swallowing volume is controlled by adjusting muscle activation timing. In addition, the timing of the swallowing reflex is slower in elderly individuals. The results confirm that the proposed approach successfully quantifies swallowing function from sEMG signals, mapping the signals to the swallowing phases.

Magnetic Resonance Imaging-Based Delineation of Organs at Risk in the Head and Neck Region

Purpose

The aim of this article is to establish a comprehensive contouring guideline for treatment planning using only magnetic resonance images through an up-to-date set of organs at risk (OARs), recommended organ boundaries, and relevant suggestions for the magnetic resonance imaging (MRI)-based delineation of OARs in the head and neck (H&N) region.

Methods and Materials

After a detailed review of the literature, MRI data were collected from the H&N region of healthy volunteers. OARs were delineated in the axial, coronal, and sagittal planes on T2-weighted sequences. Every contour defined was revised by 4 radiation oncologists and subsequently by 2 independent senior experts (H&N radiation oncologist and radiologist). After revision, the final structures were presented to the consortium partners.

Results

A definitive consensus was reached after multi-institutional review. On that basis, we provided a detailed anatomic and functional description and specific MRI characteristics of the OARs.

Conclusions

In the era of precision radiation therapy, the need for well-built, straightforward contouring guidelines is on the rise. Precise, uniform, delineation-based, automated OAR segmentation on MRI may lead to increased accuracy in terms of organ boundaries and analysis of dose-dependent sequelae for an adequate definition of normal tissue complication probability.

Evaluating Automatic Segmentation for Swallowing-Related Organs for Head and Neck Cancer

Purpose: To evaluate the accuracy of deep-learning-based auto-segmentation of the superior constrictor, middle constrictor, inferior constrictor, and larynx in comparison with a traditional multi-atlas-based method. Methods and Materials: One hundred and five computed tomography image datasets from 83 head and neck cancer patients were retrospectively collected and the superior constrictor, middle constrictor, inferior constrictor, and larynx were analyzed for deep-learning versus multi-atlas-based segmentation. Eighty-three computed tomography images (40 diagnostic computed tomography and 43 planning computed tomography) were used for training the convolutional neural network, and for atlas-based model training. The remaining 22 computed tomography datasets were used for validation of the atlas-based auto-segmentation versus deep-learning-based auto-segmentation contours, both of which were compared with the corresponding manual contours. Quantitative measures included Dice similarity coefficient, recall, precision, Hausdorff distance, 95th percentile of Hausdorff distance, and mean surface distance. Dosimetric differences between the auto-generated contours and manual contours were evaluated. Subjective evaluation was obtained from 3 clinical observers to blindly score the autosegmented structures based on the percentage of slices that require manual modification. Results: The deep-learning-based auto-segmentation versus atlas-based auto-segmentation results were compared for the superior constrictor, middle constrictor, inferior constrictor, and larynx. The mean Dice similarity coefficient values for the 4 structures were 0.67, 0.60, 0.65, and 0.84 for deep-learning-based auto-segmentation, whereas atlas-based auto-segmentation has Dice similarity coefficient results at 0.45, 0.36, 0.50, and 0.70, respectively. The mean 95th percentile of Hausdorff distance (cm) for the 4 structures were 0.41, 0.57, 0.59, and 0.54 for deep-learning-based auto-segmentation, but 0.78, 0.95, 0.96, and 1.23 for atlas-based auto-segmentation results, respectively. Similar mean dose differences were obtained from the 2 sets of autosegmented contours compared to manual contours. The dose–volume discrepancies and the average modification rates were higher with the atlas-based auto-segmentation contours. Conclusion: Swallowing-related structures are more accurately generated with DL-based versus atlas-based segmentation when compared with manual contours.

Functional swallowing outcomes related to radiation exposure to dysphagia and aspiration-related structures in patients with head and neck cancer undergoing definitive and postoperative intensity-modulated radiotherapy

BACKGROUND

The relationship between swallowing outcomes and radiotherapy dose to dysphagia and aspiration-related structures (DARS) may be different following definitive versus postoperative radiotherapy (PORT) for mucosal head and neck cancer (HNC) and has not been well-studied.

METHOD

Patient- and clinician-reported swallowing measures were prospectively collected at six time points from baseline to 24 months postradiotherapy HNC. Radiotherapy plans were retrospectively analyzed to assess dose delivered to DARS. The association between swallowing outcomes and participant demographics, tumor characteristics, and radiotherapy dose in definitive and postoperative treatment cohorts was assessed.

RESULTS

Ninety-three participants who received radiotherapy for HNC were included in the analysis (n = 49 definitive radiotherapy for laryngeal/pharyngeal primary tumors and n = 44 postoperative PORT for predominantly oral cavity/salivary gland tumors). Participants undergoing PORT had lower doses to DARS than those undergoing definitive RT. High dose to the pharyngeal constrictors and base of tongue for definitive RT and the esophageal inlet, supraglottic larynx and cervical esophagus for the PORT group were associated with worse swallowing function.

CONCLUSION

Radiation dose to DARS is associated with post-treatment swallowing outcomes. These dose/outcome relationships may vary between the definitive and postoperative settings.

Early-Stage Glottic Squamous Cell Carcinoma in the Era of Image-Guided Radiotherapy

Early-stage squamous cell cancer (SCC) of the glottis has a good prognosis. Therefore, patients have long survival outcomes and may potentially suffer from late toxicities of radiotherapy. Radiotherapy with a conventional parallel-opposed-pair or anterior-oblique beam arrangements for stage 1 and 2 glottic SCC have field borders that traditionally cover the entire larynx, exposing organs-at-risk (e.g. carotid arteries, contralateral vocal cord, contralateral arytenoid and inferior pharyngeal constrictor muscles) to high radiation doses. The potential long-term risk of cerebrovascular events has attracted much attention to the dose that carotid arteries receive. Swallow and respiratory motion of laryngeal structures has been an important factor that previously limited reduction of the radiation treatment volume. Motion has been evaluated using multiple imaging modalities and this information has been used to calculate PTV margins for generation of more limited target volumes. This review discusses the current literature surrounding dose-effect relationships for various organs-at-risk and the late toxicities that are associated with them. This article also reviews the currently available data and effects of laryngeal motions on dosimetry to the primary target. We also review the current limitations and benefits of a more targeted approach of radiotherapy for early-stage glottic SCCs and the evolution of CT-based IGRT and MR-guided radiotherapy techniques that may facilitate a shift away from a conventional 3D-conformal radiotherapy approach.

Relationship between videofluoroscopic and subjective (physician- and patient- rated) assessment of late swallowing dysfunction after (chemo) radiation: Results of a prospective observational study

BACKGROUND AND PURPOSE

Primary (chemo)radiation (CHRT) for HNC may lead to late dysphagia. The purpose of this study was to assess the pattern of swallowing disorders based on prospectively collected objective videofluoroscopic (VF) assessment and to assess the correlations between VF findings and subjective (physician- and patient-rated) swallowing measures.

MATERIAL AND METHODS

189 consecutive HNC patients receiving (CH)RT were included. Swallowing evaluation at baseline and 6 months after treatment (T6) encompassed: CTCAE v.4.0 scores (aspiration/dysphagia), PROMs: SWAL QOL/ EORTC QLQ-H&N35 (swallowing domain) questionnaires and VF evaluation: Penetration Aspiration Scale, semi-quantitative swallowing pathophysiology evaluation, temporal measures and oral/pharyngeal residue quantification. Aspiration specific PROMs (aPROMs) were selected. Correlations between late penetration/aspiration (PA_T6) and: clinical factors, CTCAE and aPROMs were assessed using uni- and multivariable analysis.

RESULTS

Prevalence of PA increased from 20% at baseline to 43% after treatment (p < 0.001). The most relevant baseline predictors for PA_T6 were: PA_T0, age, disease stage III-IV, bilateral RT and baseline aPROM 'Choking when drinking' (AUC: 0.84). In general aPROMs correlated better with VF-based PA than CTCAE scores. The most of physiological swallowing components significantly correlated and predictive for PA (i.e. Laryngeal Vestibular Closure, Laryngeal Elevation and Pharyngeal Contraction) were prone to radiation damage.

CONCLUSION

The risk of RT-induced PA is substantial. Presented prediction models for late penetration/aspiration may support patient selection for baseline and follow-up VF examination. Furthermore, all aspiration related OARs involved in aforementioned swallowing components should be addressed in swallowing sparing strategies. The dose to these structures as well as baseline PROMs should be included in future NTCP models for aspiration.

Impact of Transoral Radiofrequency Microsurgery and Radiotherapy on Long-term Swallowing Function in Patients with T1 Glottic Carcinoma

To compare the impact of transoral radiofrequency microsurgery (TRM) and radiotherapy (RT) on long-term swallowing function in patients with T1 glottic carcinoma. A total of 41 cases of T1 glottic carcinoma treated with TRM or RT alone more than 5 years ago were collected, including 17 cases treated with TRM (TRM group) and 24 cases treated with RT (RT group). The Chinese version of the Swallowing Quality-of-Life Questionnaire (CSWAL-QOL) and videofluoroscopic swallowing study results at the last follow-up (more than 5 years after TRM or RT) were assessed. The TRM group scored significantly better than the RT group on overall CSWAL-QOL, the Frequency score, and 6 out of 10 CSWAL-QOL dimensions. The RT group scored significantly better than the TRM group only on the Communication dimension. The dysphagia score (DS) and penetration-aspiration scale (PAS) score of the TRM group were better than those of the RT group. The overall CSWAL-QOL score, the Frequency score, DS, and PAS scores were not significantly different between patients who received conventional radiotherapy and patients who received intensity-modulated radiation therapy. The RT dose was correlated with the DS. TRM provides better swallowing outcomes as compared to RT in management of early glottic cancer. In addition, there is a correlation between RT dose and dysphagia. Prospective studies should be conducted to further evaluate the impact of TRM and RT on swallowing function.

Progressive muscle loss is an independent predictor for survival in locally advanced oral cavity cancer: A longitudinal study

BACKGROUND AND PURPOSE

To investigate the association between progressive muscle loss and survival outcomes of patients with advanced-stage oral squamous cell carcinoma (OSCC) undergoing surgery and adjuvant (chemo)radiotherapy.

METHODS

We analyzed the computed tomography (CT) scans of 155 patients with stage III-IVB OSCC at baseline, at simulation CT for radiotherapy, and at 3- and 9-months post-treatment. Skeletal muscle index (SMI) was measured using CT at the C3 vertebral level. The predictors of overall survival (OS) and recurrence-free survival (RFS) were evaluated using Cox regression models.

RESULTS

The median follow-up period was 75.0 months. Fifty-one patients (32.9%) developed recurrence, with the median time from the fourth CT to recurrence being 9.1 months. The SMI progressively decreased from baseline to simulation CT by 1.1% (p = 0.006), to 3 months post-treatment by 5.1% (p < 0.001), and to 9 months post-treatment by 15.6% (p < 0.001) in patients developing recurrence. Patients without recurrence lost SMI at the simulation CT by 0.7% (p = 0.001) and at 3 months post-treatment by 2.1% (p < 0.001); their SMI returned to the baseline level at 9 months post-treatment. SMI changes were weakly correlated with changes in body mass index (BMI) (Spearman ρ, 0.13; p = 0.11). In multivariate analysis, SMI changes (per 5% decrease) were independently associated with significantly worse OS (hazard ratio: 1.88, 95% confidence interval: 1.58-2.23; p < 0.001) and RFS (hazard ratio: 1.89, 95% confidence interval: 1.61-2.20; p < 0.001).

CONCLUSION

Progressive muscle loss was independently associated with worse survival outcomes in patients with stage III-IVB OSCC. Muscle loss might not be detected by changes in BMI.

Long-term swallowing outcomes of radiotherapy and transoral laser microsurgery for T1 glottic cancer treatment

INTRODUCTION

Both CO2 transoral laser microsurgery (CO2 TOLMS) and radiotherapy (RT) are standard of care in early glottic carcinoma. However, previous studies focus on voice outcomes rather than swallowing outcomes. This study aimed to compare the late post-treatment effects of CO2 TOLMS and RT treatment on swallowing function in T1 glottic carcinoma.

METHODS

Forty patients (20 CO2 TOLMS and 20 RT) with T1 glottic cancer between May 2015 and January 2019 were included. Certain types of foods triggering dysphagia, any difficulties in bolus control, need to clean the throat, the sensation of lumping in the throat, choking, cough and xerostomia were questioned. Also, functional oral intake scale (FOIS), functional outcome swallowing scale (FOSS), Eating Assessment Tool-10 test (EAT-10) and flexible fiberoptic endoscopic examination of swallowing (FEES) findings were assessed.

RESULTS

CO2 TOLMS patients performed significantly better than the RT group regarding penetration and aspiration with 10 and 20 mL water according to the Penetration and Aspiration Scale (P < .05). The mean EAT-10 Score was found 0 in the CO2 TOLMS group, and 3.20 ± 3.24 in the RT group (P < .05) (lower score indicates a better outcome). According to the Yale Pharyngeal Residue Severity Scale for vallecula, there was no statistically significant difference in vallecular residue between the groups (P > .05). A significantly lesser residue in piriform sinus was detected in the CO2 TOLMS group compared to the RT group with 5 mL and 10 mL water, 5 mL and 20 mL honey consistency food and yogurt according to Yale Pharyngeal Residue Severity Scale (P < .05).

CONCLUSION

It is suggested that in the long term, CO2 TOLMS is more advantageous regarding swallowing function in the treatment of T1 glottic cancer.

The Five Diaphragms in Osteopathic Manipulative Medicine: Myofascial Relationships, Part 1

Working on the diaphragm muscle and the connected diaphragms is part of the respiratory-circulatory osteopathic model. The breath allows the free movement of body fluids and according to the concept of this model, the patient's health is preserved thanks to the cleaning of the tissues by means of the movement of the fluids (blood, lymph). The respiratory muscle has several systemic connections and multiple functions. The founder of osteopathic medicine emphasized the importance of the thoracic diaphragm and body health. The five diaphragms (tentorium cerebelli, tongue, thoracic outlet, thoracic diaphragm and pelvic floor) represent an important tool for the osteopath to evaluate and find a treatment strategy with the ultimate goal of patient well-being. The two articles highlight the most up-to-date scientific information on the myofascial continuum for the first time. Knowledge of myofascial connections is the basis for understanding the importance of the five diaphragms in osteopathic medicine. In this first part, the article reviews the systemic myofascial posterolateral relationships of the respiratory diaphragm; in the second I will deal with the myofascial anterolateral myofascial connections.

Late Feeding Tube Dependency in Head and Neck Cancer Patients Treated with Definitive Radiation Therapy and Concurrent Systemic Therapy

Objective

The study aimed to evaluate the impact of late swallowing dysfunction leading to percutaneous endoscopic gastrostomy (PEG) tube dependence on the overall survival (OS) in a cohort of locally advanced head and neck cancer patients treated and cured with definitive radiotherapy (RT) and concurrent systemic therapy (CST). 

Materials and methods

A total of 62 patients with locally advanced head and neck cancer were included in the analysis based on the following selection criteria: stage III, IVA, or IVB disease, treated with definitive RT and CST, no major head and neck surgery, no evidence of local or distant recurrent disease, and at least one post-RT modified barium swallow study. Patients were classified as PEG dependent or PEG independent at the time of the last follow-up. Estimates of OS were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to evaluate the impact of various clinical factors on OS.

Results

The median follow-up was 48 months (range: 7.6-235 months). The five-year OS was 64.3% in the PEG-dependent group and 86.1% in the PEG-independent group (p=0.022). Age over 70 at diagnosis was also associated with poorer OS (p=0.044). On univariate analysis, PEG dependency maintained a significantly worse OS (hazard ratio [HR]: 2.59; 95% confidence interval [CI]: 1.11-5.99, p=0.028). On multivariate analysis, PEG dependency (HR: 4.25; 95% CI: 1.33-13.62; p=0.015), advanced N stage (HR: 4.74; 95% CI: 1.17-19.26, p=0.035), and older age at diagnosis (HR: 4.37; 95% CI: 1.21-15.84; p=0.025) were significantly associated with worse OS.

Conclusions

Late PEG dependency is associated with poor OS in head and neck cancer patients cured with definitive RT and CST. Interventions designed to help head and neck cancer patients maintain swallowing function may result in improved outcomes.

Dose-volume relationship for laryngeal substructures and aspiration in patients with locally advanced head-and-neck cancer

BACKGROUND

Literature has shown a significant relationship between radiation dose to the larynx and swallowing disorders. We prospectively studied the dose-volume relationship for larynx substructures and aspiration.

METHODS

Forty nine patients with stage III/IV head-and-neck (H&N) squamous cell carcinoma were prospectively enrolled in this IRB-approved, federally funded study. All patients received IMRT-based chemoradiation therapy (CRT) and were scheduled for videofluorography (VFG) prior to CRT and at 3, 6, 9, 12, and 24 months post-CRT. Twelve laryngeal substructures were contoured in each patient: thyroid cartilage, cricoid cartilage, total epiglottis, suprahyoid epiglottis, infrahyoid epiglottis, total larynx, supraglottic larynx, subglottic larynx, glottic larynx, arytenoids, aryepiglottic (AE) folds, and glossoepiglottic fold. After exclusions, 29 patients were included in the final analysis. Incidence of aspiration at 1 year following CRT was correlated with dose-volume data to laryngeal substructures using logistic regression.

RESULTS

The median age was 54 years with 79% being non-smokers. Tumor sites included oropharynx (22), unknown primary (6), and hypopharynx (1). One year following CRT, 10/29 (34%) showed aspiration on VFG. Dose to the AE folds showed the highest correlation with aspiration at 12 months and was significant on multivariate analysis (p = 0.025). A mean dose cutpoint of 6500 cGy or higher to the AE folds was associated with an increased risk of aspiration at 1 year [positive likelihood ratio (+LR) 2.81, positive predictive value (PPV) 60%, negative predictive value (NPV) 92.9%, relative risk (RR) 8.4].

CONCLUSIONS

In this analysis, mean dose to the AE folds was associated with an increased risk of aspiration at 1 year. However, these are hypothesis-generating data that require further research and validation in a larger patient subset.