Use of Radiotherapy for Control of Sialorrhea in Patients with Amyotrophic Lateral Sclerosis

Many patients with amyotrophic lateral sclerosis (ALS) develop progressive difficulty with swallowing secretions, and drooling becomes a significant problem. The production of saliva can be reduced with radiation of the submandibular and sublingual salivary gland tissue. This method has been used successfully in Europe and had limited use at Vancouver Hospital. This study was undertaken to determine the lowest effective dose of radiation necessary to control salivary production. Over a 3-year period, patients with ALS who developed significant problems with drooling were identified and treated with a predetermined dose of radiation. The first group received a single dose of 8 Gy in one fraction and the second received a total of 12.5 Gy in two fractions. They were followed over the next 6 months and were evaluated for effectiveness and side effects. Their saliva was measured pre- and postradiation treatment, and they were also asked to evaluate the change subjectively, using a questionnaire. The preliminary findings suggest that 8 Gy of radiation was effective in controlling drooling, and increasing the dose did not improve initial control. Long-term control was difficult to evaluate as the patients entered in the study were very ill and their life expectancy was very short. Radiation at this low dose resulted in very few side effects. Low-dose radiation can safely help control secretions in selected patients with ALS.