Radiotherapy treatment of sialorrhea in patients with amyotrophic lateral sclerosis requiring non-invasive ventilation.

Abstract

In amyotrophic lateral sclerosis (ALS), bulbar dysfunction may lead to sialorrhea [1], which affects up to 25 % of patients [2], and is a significant purveyor of distress trough a permanent drooling mouth, an increased risk of saliva aspiration pneumonia and a limited tolerance of non-invasive ventilation (NIV). We recently demonstrated that radiotherapy (RT) of the salivary glands was efficient and safe in the treatment of refractory sialorrhea in ALS [3]. Nevertheless, when orthopnoea occurs, decubitus position necessary to RT requires NIV. Performing RT in patients undergoing mechanical ventilation is technically challenging. The objective of this pilot study was to evaluate the efficacy and tolerance of a new protocol of RT specifically designed for ALS patients requiring mechanical ventilation for decubitus position. Five ALS patients, with established ALS according to revised El Escorial criteria [4], respiratory insufficiency and profuse sialorrhea resistant to classical pharmacological treatments (atropine drops, hyoscine patches and amitriptyline) were included. For patient characteristics see Table 1. All patients had severe orthopnea and were treated, at least over night, with non-invasive positive pressure ventilation without oxygen, using a facial mask. Irradiation was performed at the Clinique de la Porte de Saint-Cloud (Boulogne, France). Treatment was delivered through a conventional linear accelerator with 6 MV photons in both submandibular glands and two thirds of both parotid glands. Patients lied during sessions in 30 decubitus position for a maximum period of 10 min. The thermoplastic mask for radiotherapy was specifically designed to fit the facial mask of NIV, incorporating a large opening over the mouth and nose (Fig. 1). RT efficacy was assessed with the Sialorrhea Scoring Scale (SSS) that we previously validated in ALS patients [5]. The scale allows a semiquantification of sialorrhea in 9 grades ranging from 1 (dry mouth) to 9 (profuse sialorrhea). Approval for the study was obtained from the Regional Committee for Medical Research Ethics. Irradiation was completed in all 5 cases without any perprocedure complication. Assessment at the end of RT showed improvement in all patients with complete response (CR: SSS 1–3) in 4 cases and partial response (PR: SSS 4–5) in one case. Further evaluation at 3 months revealed persistent significant reduction in salivary production with 3 patients maintaining a CR and 2 patients a PR. Mild pain (acute toxicity of RT grade 1–2) was observed in 1 patient, but resolved in the weeks following the end of treatment. & Pierre-Francois Pradat pierre-francois.pradat@psl.aphp.fr