Application of Low-Level Laser Therapy for Analgesia of Odinophagy Caused by Head and Neck Radiotherapy: Anatomic Study and Clinical Protocol Proposal

Introduction: Oral and hypopharyngeal mucositis are considered acute effects of great importance of radiotherapy. Patients present painful ulcers, dysphagia, odynophagia and difficulties in speaking, which can lead to malnutrition and treatment discontinuation. Currently, photobiomodulation therapy, using low-level laser therapy is the treatment of choice for oral mucositis. Objective: To propose the use of extraoral laser therapy to treat odynophagia associated with radioinduced hypopharyngeal mucositis. Methods: Pilot study divided into two stages: (1) Anatomical study in cadavers, to select the best area of application of the extraoral laser in the cervical region to reach the hypopharynx. In this stage, we opted for the use of low-level light therapy (XXXXX®), continuous mode, λ660nm, 100mW power, 0.028cm2 spot. (2) Application of extraoral photobiomodulation for patients with odynophagia associated with oral and hypopharyngeal mucositis. The same low-level laser therapy (XXXXX®,) was used, but with λ808nm, 100mW power and 4J energy, 40 pulses per point. Reports of three patients who underwent treatment were collected, transcribed and reviewed qualitatively. Results: (1) The anatomical region that allowed better access of extraoral laser therapy to the hypopharynx was the carotid triangle. (2) Patients reported reduced odynophagia and greater comfort with the use of this treatment. Conclusion: The carotid trigone was the best extraoral region for laser application to reach the hypopharyngeal region. The laser therapy protocol applied in this region brought comfort to the patients assessed. Further studies are needed to assess the analgesic capacity of this treatment.