Vocal fold paralysis following radiotherapy for nasopharyngeal carcinoma: laryngeal electromyography findings

Radiation therapy-induced left vocal cord paralysis following lung stereotactic body radiation therapy: A case report and review of the literature

We report the case of a 50-year old women with an oncological history of metastatic breast carcinoma who underwent lung stereotactic body radiation therapy (SBRT) of 60Gy in 8 fractions for a left upper lobe metastatic lesion. Seven months later, she complains about hoarseness and weakness of voice. Tumoral relapse and other frequent etiologies were excluded. The diagnosis of radiation induced left recurrent laryngeal nerve paralysis causing left vocal cord paralysis (VCP) was made. The symptomatology did not improve till the disease progression and death of the patient 29 months after SBRT. VCP after lung SBRT is a rare adverse event that has not yet been well described in the medical literature.

Delayed lower cranial neuropathy after oropharyngeal intensity-modulated radiotherapy: A cohort analysis and literature review

BACKGROUND

The purpose of this study was to examine swallowing-related lower cranial nerve palsy (LCNP) in oropharyngeal cancer (OPC) survivors after intensity-modulated radiotherapy (IMRT).

METHODS

Patients treated with definitive IMRT (66-72 Gy) were pooled from institutional trial databases. Prospective analyses on parent trials included videofluoroscopy, clinical LCNP examination, and questionnaires pre-IMRT, 6 months post-IMRT, 12 months post-IMRT, and 24 months post-IMRT. Time-to-event and incidence of LCNP was estimated with competing risk methods. Literature review (1977-2015) summarized published LCNP outcomes.

RESULTS

Three of 59 oropharyngeal cancer survivors with a minimum 2-year follow-up developed hypoglossal palsy ipsilateral to the index tumor (median latency 6.7 years; range 4.6-7.6 years). At a median of 5.7 years, cumulative incidence of LCNP was 5%. LCNP preceded progressive dysphagia in all cases. Published studies found median incidence of radiation-associated LCNP was 10.5% after NPC, but no OPC cancer-specific estimate.

CONCLUSION

Although uncommon, the potential for late LCNP preceding swallowing deterioration highlights the importance of long-term functional surveillance in OPC survivorship.

Vocal Fold Paralysis as a Delayed Consequence of Neck and Chest Radiotherapy

Objective

To describe a series of cases of vocal fold paralysis years after radiation therapy, including presentation, clinical course, and treatment.

Study Design

Case series with chart review.

Setting

Tertiary care center.

Subjects and Methods

A review of 8 years of patient records yielded 10 patients (8 male and 2 female; average age 57 years [range, 29-76 years]) with vocal fold paralysis and a history of radiation therapy to the head, neck, or mediastinum. These patients did not have other possible etiologies of vocal fold paralysis. Demographic, diagnostic, clinical course, and treatment data were collected.

Results

On average, 21 years (range, 1-27 years) elapsed between completion of radiation and presentation with vocal fold paralysis. Original pathologies included Hodgkin lymphoma (5), squamous cell carcinoma of the head and neck (4), and peripheral T-cell lymphoma (1). Eight patients had unilateral left vocal fold paralysis, and 2 had bilateral neuropathy; none recovered spontaneously. All patients had dysphonia, and nearly all patients also complained of dysphagia. Six elected not to be treated. Four underwent injection augmentation with resolution of voice complaints.

Conclusions

Radiation therapy has the potential to cause laryngeal neuropathy years to decades after treatment. The potential for recovery is low, but injection augmentation can relieve symptoms. Development of contralateral neuropathy and altered tissue response are considerations in treatment.

Laryngeal electromyography findings of vocal fold immobility in patients after radiotherapy for nasopharyngeal carcinoma

BACKGROUND

The clinical features of vocal fold immobility (VFI) after radiotherapy for nasopharyngeal carcinoma (NPC) have seldom been reported.

METHODS

We retrospectively reviewed laryngeal electromyography (LEMG) and tumor study findings to elucidate the common clinical features of patients who presented with VFI after radiotherapy for NPC. The LEMG signals obtained from the cricothyroid and thyroarytenoid muscles were used to confirm superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) injury.

RESULTS

The medical records of 13 patients were reviewed and 11 of them had evidence of RLN injury. Six of the 11 patients also had SLN injury, indicating possible vagus nerve (VN) injury. Two patients had cricoarytenoid joint fixation without evidence of nerve injury. None of the nerve injuries were caused by skull base recurrence or tumor metastasis.

CONCLUSION

VFI is usually caused by nerve injury, but it is not a malignant sign of tumor recurrence or metastasis.

Voice of Postradiotherapy Nasopharyngeal Carcinoma Patients: Evidence of Vocal Tract Effect

This study was aimed at identifying acoustic and physiological measures useful for monitoring voice changes in postnasopharyngeal patients with nonlaryngeal malignancies, and providing evidences of vocal tract effect on voice through comparisons between individuals with and without intact vocal tract. Simultaneous acoustic-electroglottographic signals recorded during phonation of vowels /i/ and /a/ sustained at habitual, high, and low pitch levels were compared among 10 postradiotherapy patients with nasopharyngeal carcinoma (NPC), 10 voice patients (VPs) with intact vocal tract, and 10 healthy individuals with normal voice (NORM). Results from a series of discriminant analyses revealed that the NPC group generally exhibited lower signal-to-noise (SNR) and open quotient (OQ) and higher Formant 1 frequency (F(1)) and speed quotient (SQ) than the NORM group. Unlike both VP and NORM groups, the NPC group failed to show a pitch effect on all voice measures, including OQ, SQ, percent jitter, percent shimmer, and SNR, suggesting an effect of radiotherapy and/or vocal tract on laryngeal behaviors. For the vowel /i/, on the other hand, only the NPC and NORM groups showed a pattern of pitch-dependent F(1) raising, a reflection of increased pharyngeal narrowing. These findings suggested that the pitch effect on laryngeal behaviors differed not only between individuals with intact vocal tract and those without but also between those with structural and dynamic changes of vocal tract.