Management of radiotherapy-induced hyposalivation using photobiomodulation therapy: a case series

It is not uncommon for individuals receiving radiotherapy for head and cancers to experience dry mouth sensation (xerostomia), salivary hypofunction (hyposalivation) and taste changes. The present study aimed to evaluate the short-term effectiveness of biweekly photobiomodulation therapy (PBMT) in managing these radiotherapy-induced adverse effects and its impact on oral health-related quality of life. Ten patients who developed xerostomia and hyposalivation secondary to radiotherapy for head and neck cancer were included. The study assessments included clinician-based [the stimulated (SSF) and unstimulated salivary flow (USSF) and taste change questionnaire] and patient-based measures [Shortened Xerostomia Inventory (SXI) and Oral Health Impact Profile (OHIP-5)]. The 10 participants (males = 5, females = 5) had a mean age of 52 (± 15) years. Half were diagnosed with nasopharyngeal squamous cell carcinoma. From visits 1 to 8, 80% showed increased USSF and/or SSF, but these were limited and not significant (p > 0.05). Nevertheless, 80% of the patients had lower xerostomia scores, 60% had less dryness frequency, and 40% showed taste improvement. Improvement in oral health-related quality of life was only observed in 30% of the participants. Strong proportional correlations were found between USSF and SSF as well as SXI and OHIP-5 at study visits 1 and 8 (p < 0.05). The findings showed the usefulness of PBMT in reducing xerostomia and taste changes and possibly increasing salivary flow over a 4-week duration. However, randomised clinical trials are needed to assess the long-term effectiveness of PBMT compared to other management options.Clinical study registration: The study was prospectively registered with the US National Library of Medicine's clinical trial registry on 13 September 2022 [ClinicalTrials.gov ref: NCT05538169].