Koutou (THE LARYNX JAPAN) Vol. 28(2016) No. 2

High-speed digital imaging (HSDI) has not yet been integrated into the daily clinical practice of phonosurgeons. The lack of a standard analysis method is one of the primary reasons for this. The authors herein propose a standard HSDI analysis method.

The visual-perceptual rating is a standard analysis method for videostroboscopy. Although it is subjective, it is fast and easy to complete. Since no visual-perceptual rating protocol has been proposed for HSDI, the authors introduced a new assessment form for HSDI. Laryngotopography is a method that uses fast Fourier transformation on the brightness curve of pixels. This method provides spatial vibratory data (lateral plus longitudinal data), which allows phonosurgeons (accustomed to 2-D endoscopic view) to intuitively grasp the general vibratory dynamics. Kymography, a classical analysis method for HSDI, allows for the evaluation of lateral and temporal data. The glottal area waveform is another classical method that can be applied to the analysis of HSDI, which provides temporal information related to the glottal area. Since the quantitative parameters for the last three techniques were limited, the authors introduced a number of novel parameters to enhance quantitative capacity in the analysis of HSDI.

Although the proposed method is still preliminary, it is easy to understand, and capable of sufficiently assessing three dimensions of HSDI data (lateral, longitudinal and temporal).

INTRODUCTION: Several studies have reported that loud phonation and frequent throat clearing are problematic behaviors for vocal hygiene. It is presumed that strong collision between the vocal folds during loud phonation or throat clearing injures the laryngeal tissue. However, in normal video images (30 frames/s), it is not possible to continuously measure the velocity of rapid vocal fold adduction. In the present study, we attempted to investigate whether the velocity of vocal fold adduction in the onset of loud phonation and throat clearing is faster in comparison to natural phonation, and whether humming, as a vocal training technique, affects the velocity of vocal fold adduction in the onset of phonation using high-speed digital imaging (HSDI) with high time resolution.

MATERIALS AND METHODS: Twenty normal healthy adults were enrolled in the present study. A transnasal flexible fiberscope connected to a high-speed camera was inserted, then each participant was asked to perform weak/strong throat clearing (TC) and three phonatory tasks: natural /e:/ phonation (NP), loud /e:/ phonation (LP) and humming /m:/ phonation (HP), and the high-speed laryngeal findings were recorded at a rate of 4,000 frames/s. The vocal fold angular velocities were calculated during vocal fold adduction from three points (the anterior commissure and the tips of the bilateral vocal processes) using the Dipp-Motion Pro motion analysis software program (DITECT, Japan). In addition, the average angular velocities were calculated in the ranges of 100–80%, 80–20% and 20–0% from all of the angular changes. These measurements were compared among the five tasks.

RESULTS: The pattern of the changes in the angle between the vocal folds drew sigmoid curves and polynomial curves in NP/HP and TC/LP, respectively. The angular velocity during weak/strong TC and LP continuously accelerated, whereas the angular velocity during NP and HP accelerated once, but then decelerated. The average angular velocity of each range in strong TC was significantly greater than that in NP; in particular, the 20–0% average angular velocity was approximately two-fold greater than that in NP. The average angular velocity of each range in HP was significantly smaller than that in NP, and the 20–0% average angular velocity was approximately half of that which was observed in NP.

CONCLUSION: The present study demonstrated that HSDI enables the continuous analysis of the velocity of vocal fold adduction, and that TC/LP increases the velocity of vocal fold adduction in a continuous manner, producing intense collision just before vocal fold contact. In contrast, HP was found to decrease the velocity of vocal fold adduction, perhaps leading to the weakening of the collision force at the end of vocal fold adduction.

Laryngeal stroboscopy and high-speed digital imaging (HSDI) of the larynx are methods that allow for the intuitive evaluation of vocal cord vibration based on visual information. Both examinations enable the objective evaluation of vocal cord vibration based on information obtained from imaging. However, previous studies have revealed that HSDI is superior to stroboscopy in certain areas. To analyze the objective information from HSDI, we performed a kymograph edge analysis (KEA) and used the glottal area waveform (GAW) to evaluate the vocal cord vibration of the patients with various laryngeal diseases. Moreover, we developed a software program that can automatically calculate the anterior to posterior and left to right phase difference from KEA. We noticed a slight difference in both the amplitude and duration of vocal cord vibration in each glottal cycle. We referred to this as “perturbation of vocal cord vibration” and hypothesized that this perturbation is associated with conventional factors that cause perturbation in the acoustic analysis. We compared the perturbation data from HSDI and the acoustic analysis. A significant correlation in the degree of perturbation was observed in the two examinations. The results of our study suggest that HSDI could be used to evaluate perturbation of the vocal cord vibration in each glottal cycle.

The current definitive treatment for laryngeal cancer is surgery and radiotherapy. Radiotherapy with or without concurrent chemotherapy is used to preserve the function of the organs; however, more than a few patients experience residual or recurrent lesions after radiotherapy-based treatment. Not all such patients undergo salvage surgery, and salvage surgery after irradiation is associated with a high complication rates. A precise prediction of the response to radiotherapy-based treatment is therefore warranted.

We previously reported that the metabolic tumor volume（MTV）, a volumetric parameter of FDG-PET, of a primary tumor was an independent predictive and prognostic factor in laryngeal cancer treated by a radiotherapy-based protocol. Patients with residual disease showed a significantly higher MTV than those with a complete response after primary treatment. According to a multivariate analysis, MTV was found to be an independent prognostic factor for survival.

Next, we evaluated the difference in the survival outcomes of surgery-based and radiotherapy-based treatment in patients with high-MTV laryngeal cancer. Patients with high-MTV laryngeal cancer who were treated by a surgery-based protocol showed better survival than those who underwent radiotherapy-based treatment. These results imply that the MTV could be an important factor when planning the treatment strategy for patients with laryngeal cancer.

We performed transoral videolaryngoscopic surgery (TOVS) for hypopharyngeal and supraglottic cancer after induction chemotherapy. The data of 24 patients with hypopharyngeal and supraglottic cancer were retrospectively analyzed. The main tumor site was the hypopharynx in 20 cases and the supraglottis in 4 cases. The number of patients with stage II, III, IVA and IVB tumors were 3, 4, 15 and 2, respectively. Although the mean observation period was relatively short (33 months), the 3-year overall survival was 86%, the disease-specific survival was 94% and the laryngeal preservation rate was 94%. The oncological results and laryngeal preservation rate were excellent.

The pathological findings showed that caution must be taken against local recurrence because of possible satellite residual cancer. In principle, the resection area should be set according to the original tumor extension. Although the resection area was reduced in some cases, we cannot conclude whether or not the resection area can be safely reduced in all cases.

We also examined the need for adjuvant (chemo) radiotherapy. If the resection area was set according to the original tumor extension, negative margin, pT1-2 and pN0-1, adjuvant radiation therapy may be preserved.

The study introduced methods that allow for the subjective evaluation of dysphonia patients using the Japanese recommended versions of evaluation tools such as the Voice Handicap Index (VHI) and the VoiceRelated Quality of Life (V-RQOL). The results were reported at our department. The VHI and V-RQOL scores of healthy subjects were the same as those in previous reports. In addition, a negative correlation between the VHI and V-RQOL scores was recognized. In the dysphonia cases, female patients and patients in their 20s and 30s showed poor VHI and V-RQOL scores. Patients with functional dysphonia and vocal cord paralysis showed poor VHI and V-RQOL scores. The scores were recognized to improve after treatment and were useful for the evaluation of treatment effect. Based on the results of the present study, it was considered that both the VHI and V-RQOL could be objectively-effective tools that allow for the subjective evaluation of dysphonia, and that they should be implemented in a proactive manner.

In general, the evaluation of the degree of abnormal voice quality has a crucial role in the clinical assessment of voice-disordered patients. As the gold standard for the assessment of voice quality, auditory-perceptual methods have been utilized worldwide. However, the subjective nature of these methods can strongly influence the reliability and accuracy of the evaluation. Due to such limitations, acoustic measurements have been developed to increase the objectivity in the evaluation of voices.

In this article, we first review the traditional acoustic measures to improve our understanding of the principles of acoustic analyses. Subsequently, for clinical practice, we introduce several available instruments, such as analysis software programs and microphones, that are suitable for acoustic analyses. Lastly, we describe the differences between two software programs and two microphones, and discuss their respective utility.

The examination of the larynx is important not only for diagnostic purposes but also for planning the optimal treatment strategy. The usefulness of the laryngeal stroboscope, flexible laryngoscopy and neck computed-tomography, all of which are generally used to examine dysphonia patients is reported.

Laryngeal stroboscope

This instrument is useful for the evaluation of abnormalities in the vocal cord mucosa. The symmetry of movement of the bilateral, vocal cords, regularity of vibration, glottal closure, amplitude and mucosal wave are examined with this instrument. It is important to observe not only fixed pitch and loudness of voice but also changed state. While this examination is a qualitative examination. A quantitative comparison between pretreatment and posttreatment is possible using the instrument's recording function.

Flexible laryngoscopy

This examination is useful for the evaluation of movement disorders of the vocal cords. Flexible laryngoscopy is more adept than a telescope examination in the observation of the periphery of the anterior commissure, although the observation of the posterior glottis is difficult. To observe a vocal cord lesion carefully, we must consider the nasal cavity through which the flexible laryngoscope will pass （right or left）. In addition, we must also consider whether the flexible laryngoscope will pass between the middle nasal meatus or common nasal meatus.

Computed-tomography

Reconstruction of perpendicular coronal and parallel axial sections of the vocal cords is useful in voice restitution operations. As such, three-dimensional computed tomography is useful for imagining the pathosis.

Dysphagia has now become a common disease in Japan, and the presence of otolaryngologists is more significant in the dysphagia clinics. Impaired swallowing function can easily cause suffocation and aspiration pneumonia which can be induced by food, saliva and stomach acid. Patients with dementia could have a suffocation by filling up food in their mouth. Although the aspiration pneumonia in elderly patients is difficult to avoid, an oral diet can often be continued with appropriate treatment.

Multidisciplinary team approach is necessary in the field of swallowing medicine, however the otolaryngologist can play a leading role in the team evaluating the swallowing function and treating the dysphagia and pneumonia.

The usefulness of rehabilitation for dysphagia is widely recognized. However, the effectiveness of surgery for dysphagia is only recognized by some otolaryngologists and rehabilitation specialists. We experienced a case in which a drastic improvement in the patient’s quality of life was obtained after surgery for disphagia. Surgery for dysphagia is surgical rehabilitation in the therapy procedure in deglutition rehabilitation. Patients in whom surgery is indicated have various problems, and the support of a specialist team is required. Suitable management is necessary for surgery.

The last two decades have seen increasing adoption of chemoradiation protocols for the treatment of laryngeal cancer, despite varying data about how effective these treatments are on critical outcomes such as swallowing. The relative rarity of these tumors prevents single institutions from assembling the number of patients needed to achieve meaningful insights, and therefore there is need for multi-institutional prospective data collection to understand the effects of treatment after advanced laryngeal cancer. Unfortunately, the challenges and high costs of multi-institutional data collection and data management have discouraged head and neck cancer clinicians from pursuing large, multi-institutional prospective studies to address these questions.

We are at a point where clinicians have strong opinions but little data, while we are recommending drastically different forms of treatment for our patients. This talk will focus on the state of evidence to date and our best understanding of quality of life after treatment for advanced laryngeal cancer. We will discuss the rationale for the Treatment for Advanced Laryngeal Cancer (TALC) cohort study. This non-randomized, multi-institutional cohort study is now reaching completion, and was started with the principle goal of identifying predictors of swallowing function after treatment.

We will the success of the TALC study in gathering data in multi-institutional fashion. The TALC study uses a novel approach to data collection, because although it involves multiple North American institutions, it has only one paid research coordinator. Data collection and management is handled at the central coordinating site with the help of a web-based data collection tool. This common, shared website (https://talc.ahc.umn.edu/) has capability for data entry, collection, and storage. It also houses study documents, including regulatory documents and paper back-up data collection forms.

The study has now completed enrollment and results of the trial are still being analyzed. We have enrolled 279 patients, well over the original target of 220 patients. Of 45 North American institutions who obtained IRB approval to participate, 39 institutions were able to contribute patients. We have complete data on 158 patients who have survived a full year, and have completed all forms and CT scans. We are still collecting final data on a number of other patients, and preliminary insights into swallowing function are intriguing. The findings will be presented at the 9th International Conference on Head & Neck Cancer in Seattle, Washington, USA in August of 2016.

The TALC study provides incremental improvement for not only understanding of outcomes after treatment for advanced laryngeal cancer, but also a basis for future efforts in multi-institutional prospective data collection with inexpensive infrastructure. We hope that this framework will encourage interested, collaborative head and neck surgeons around the world to pursue common data collection.

Relapsing polychondritis is a relatively rare disease that attacks the cartilage and connective tissue. We will herein report 2 cases of RP arising in the larynx.

Case 1: A 59-year-old woman visited our hospital with roughness of voice, wheezing, and dyspnea. An endoscopic examination revealed a suspected submucosal tumor from the left arytenoid region to the false vocal cord. We performed tracheostomy and a biopsy of the swollen mucosa; however, no tumor was found. We then performed a biopsy of the thyroid cartilage, which showed inflammation. A biopsy of the auricular cartilage also showed inflammation, and relapsing polychondritis was diagnosed.

Case 2: A 79-year-old woman with worsening dyspnea visited our hospital. Endoscopic examination revealed subglottic stenosis. We performed tracheostomy and a biopsy of the auricular cartilage; however, no inflammation was found. Dyspnea disappeared spontaneously. Nine months after the first visit, she presented strong dyspnea. An endoscopic examination revealed stenosis and mucous membrane swelling from the part of the trachea that was caudal to the stoma to the bronchus; however, no inflammation was detected in the biopsy of the bronchial mucosa. Twelve months after the first visit, the both sides of auricle swelled, and relapsing polychondritis was diagnosed. Since it was not always easy to indentify inflammatory in case 2, we should consider other clinical findings, the effectiveness of steroids, and auricular cartilage biopsy, if necessary, for the early diagnosis of relapsing polytchondritis in order to reduce the risk for respiratory failure.