Risk factors for voice quality after radiotherapy for early glottic cancer

Abstract 

Background and purpose

In the majority of patients irradiated for early glottic cancer an abnormal voice was reported. The purpose of the study was to determine the factors influencing voice quality after radiotherapy for T1 glottic cancer.

Methods

The voices of 75 male patients irradiated for T1 glottic carcinoma were assessed subjectively and objectively by acoustic analyses and aerodynamic measurements. The laryngeal function and morphology were evaluated by videolaryngostroboscopy. The data on smoking habits, the associated diseases influencing voice quality, the extent of the tumor, the type of biopsy, and the irradiation technique were collected from the medical records. The data on the factors influencing voice quality were compared for patients with a normal/near-normal voice and those with a hoarse voice.

Results

Voice quality was at least slightly abnormal in 94.7% and 81.3% of patients, when assessed perceptively and objectively, respectively. Smoking after the completed treatment, more severe morphologic alterations of the vocal folds, dryness of the throat, incomplete closure of the vocal folds and functional voice disorders expressed as supraglottic activity adversely influenced the voice quality. A good correlation between the perceptive voice assessment and the acoustic analyses was established.

Conclusions

After the successful irradiation for T1 glottic carcinoma, the great majority of the patients have at least a slightly hoarse voice. A better voice outcome could be achieved if radiotherapy was followed by the patient’s cessation of smoking and the appropriate voice therapy.

Keywords: Glottis cancer, Irradiation, Voice quality, Acoustic analysis, Perceptive evaluation