Behavioral Rehabilitation of Radiation-Induced Unilateral Vocal Fold Palsy after Breast Cancer Treatment Using the Lee Silverman Voice Treatment Program: A Case Study

Article excerpt

Keywords: breast cancer, unilateral vocal fold palsy, behavioral voice therapy, Lee Silverman Voice Treatment (LSVT), Voice Handicap Index (VHI)

Vocal fold paralysis is a rare but functionally limiting side effect of radiation treatment for breast cancer. The current case study documents the management of a 79-year-old woman who presented with vocal fold palsy after radiation treatment for breast cancer more than 10 years previously. Treatment before the current case report involved a failed attempt of surgical intervention which was followed by a period of traditional behavioral voice therapy that had no discernable impact on either vocal fold function or voice quality. The Lee Silverman Voice Treatment (LSVT) was subsequently conducted to determine if intensive behavioral voice treatment could achieve a behavioral change. Endoscopic evaluation of laryngeal function as well as acoustic and perceptual voice assessments were conducted before, after, and at 6 months after the LSVT. After treatment, there was increased compensatory movement of the unaffected vocal fold, improving approximation to the paralyzed vocal fold. Acoustic and perceptual assessments also revealed small but clinically significant increases in perceptual voice quality, vocal loudness, and overall intelligibility. Despite the chronic nature of the vocal fold paralysis in this case, the case study demonstrates that intensive voice treatment using the LSVT helped to achieve a small but positive impact on both vocal fold function and voice quality.

INTRODUCTION

Breast cancer is the most common cancer to affect women, and it is estimated that up to 14,000 women will be diagnosed with breast cancer in Australia every year (Australian Institute of Health and Welfare, 2005). The 5-year survival rate for breast cancer is high at over 88% (Australian Institute of Health and Welfare, 2005). As such, many women continue to live with the side effects of breast cancer treatment for decades after remission. Radiotherapy is one of the common treatment modalities used to treat breast cancer, either alone or in conjunction with surgery (National Breast and Ovarian Cancer Centre, 2009). When planning treatment, oncologists aim to provide the best possible outcome with regard to disease response while aiming to reduce associated comorbidities (Hopwood et al., 2010).

Chronic side effects after treatment for breast cancer include skin changes, lymphedema, fibrosis, and neuropathy (Johansson, Svensson, & Denekamp, 2000; Westbrook, Ballantyne, Eckles, & Brown, 1974). Specifically, radiation-induced nerve damage can involve the brachial plexus; phrenic nerve; and less commonly, the recurrent laryngeal nerve (Johansson, Lofroth, & Denekamp, 2001). Damage to the recurrent laryngeal nerve, which is a branch of the vagus nerve, results in vocal fold paralysis and a voice disorder characterized by a hoarse, weak, breathy voice. Johansson et al. (2001) found that 8% (12 of 150) of patients who were followed up for several years after radiation for breast cancer had developed unilateral vocal fold paralysis related to radiation treatment. Metastatic disease was eliminated as a cause of the vocal fold paralysis, and the authors hypothesized that the mechanism of this damage was fibrosis of the recurrent laryngeal nerve at the mediastinal margin. It must be acknowledged, though, that the participants in this study received postoperative radiation therapy between 1963 and 1965, and the authors acknowledged that radiation treatment has evolved markedly since that time. Thus, it is likely that the incidence of vocal fold paralysis secondary to damage to the recurrent laryngeal nerve could be lower in patients treated with current radiation techniques. Regardless of this possible reduction in incidence, vocal fold paralysis must be acknowledged as a possible potential chronic side effect of radiation for breast cancer that will require management. …