Effect of 635nm Diode Laser on Radiation Induced Xerostomia Patients

Abstract

Background: Xerostomia, one of the most major side effects of radiotherapy in patients with oropharyngeal cancer, has a compromising effect on the quality of life. The aim of this study was to evaluate the effect of 635nm low-level laser on salivary flow rate and quality of life (QoL) in post-radiotherapy oropharyngeal cancer patients.

Methods: A prospective study was conducted on patients (n=34) with persistent post-radiotherapy xerostomia received low level laser therapy (LLLT) (635nm) on the three major salivary glands twice a week for 12 weeks. For each point, dose was 18.75 J/cm2, irradiation time was 15 s, energy was 1.5 J. Energy for each session was 33 J and laser tip diameter was 0.08cm2. Extra oral points were marked over the parotid gland (6 points), submandibular (3points) and sublingual gland (2 points). Unstimulated and stimulated salivary flow rate (SFR) and quality of life (QoL) using University of Washington (UW) QoL questionnaire were assessed. Unstimulated SFR and QOL scores were normally distributed and hence paired t-test was used. A p-value ≤0.05 was considered as statistically significant.

Results: The mean unstimulated SFR was significantly increased by 0.16 units after LLLT (p=0.001). Similarly, the median stimulated SFR significantly increased by 0.45 units post LLLT respectively (p=0.001). The mean QoL was significantly increased by 591.32 units after LLLT (p≤0.05).

Conclusion: Low level laser therapy (LLLT) demonstrates to be effective in increasing salivary flow rate and the QoL scores hence mitigating salivary hypofunction and improving overall quality of life of patients.

Keywords: Low-Level Laser Therapy; Xerostomia.