Sialorrhoea (or ‘drooling’) is a common complication of many neurodegenerative disorders that cause swallowing problems, such as in amyotrophic lateral sclerosis (ALS) and Parkinson’s disease. Patients are at risk of aspiration and pneumonia. ‘Drooling’ may further be an important cause of social isolation and embarrassment. Anticholinergic drugs are the usual first-line treatment, but these drugs may have severe side effects. Saliva production can be reduced by relatively low-dose irradiation.

Patients and methods: Between 1996 and 2008, 53 patients were irradiated on both parotid glands for sialorrhoea in 43 patients with ALS and 10 patients with Parkinson’s disease. The radiation dose was 12 Gray in 2 fractions of 6 Gray with a one-week interval using 250 kv orthovoltage or 8-14 MeV megavoltage electrons.

Results: The mean survival time was 13.7 months. In surviving patients the mean duration to reirradiation was 11.9 months; the mean duration of successful remission of sialorrhoea was 6.9 months in patients with ALS and 6,5 months in patients with Parkinson’s disease. This implies that in these critically ill patients, 50% and 25% will be successfully palliated for sialorrhoea during their residual lifespan. Reirradiation of recurring sialorrhoea was effective in 21 of 26 patients (81%); however, most patients had only partial relief (16/26; 62%).

Conclusion: Low-dose radiotherapy is a simple and effective treatment of sialorrhoea in patients with ALS or Parkinson’s disease.

This supplementary information is presented as submitted by the corresponding author. It has not been copy-edited by NTvG.