Radiation Therapy for Hypersalivation: A Prospective Study in 50 Amyotrophic Lateral Sclerosis Patients

Purpose: This study aimed to evaluate the efficiency and the tolerance of radiation therapy (RT) on salivary glands in a large series of amyotrophic lateral sclerosis (ALS) patients with hypersalivation. Methods and Materials: Fifty ALS patients that had medically failure pretreatment were included in this prospective study. RT was delivered through a conventional linear accelerator with 6-MV photons and 2 opposed beams fields including both submandibular glands and two-thirds of both parotid glands. Total RT dose was 10 Gy in 2 fractions (n=30) or 20 Gy in 4 fractions (n=20). RT efficacy was assessed with the 9-grade Sialorrhea Scoring Scale (SSS), recently prospectively validated as the most effective and sensitive tool to measure sialorrhea in ALS patients. Results: At the end of RT, all patients had improved: 46 had a complete response (92% CR, SSS 1-3) and 4 had a partial response (8% PR, SSS 4-5). A significant lasting salivary reduction was observed 6 months after RT completion: there was 71% CR and 26% PR, and there was a significant SSS reduction versus baseline (P<10⁻⁶). There was no grade 3 to 4 toxicity, and most side effects (34%) occurred during RT. Nine patients (18%) underwent a second salivary gland RT course, with a 3-months mean delay from the first RT, resulting in a SSS decrease (−77%). Both RT dose regimens induced a significant SSS decrease with no significant toxicity. There were, however, more patients with CR/PR in the 20-Gy protocol (P=.02), and 8 of 9 patients (89%) receiving a second RT course had previously been treated within the 10-Gy protocol. Conclusion: Radiation therapy of 20 Gy in 4 fractions is an efficient and safe treatment for ALS patients with sialorrhea. A shorter RT course (10 Gy in 2 fractions) may be proposed in patients in poor medical condition