Low-energy He Ne laser in the prevention of radiation-induced mucositis - A multicenter phase III randomized study in patients with head and neck cancer

Use of the low-energy helium-neon laser (LEL) appears to be a simple atraum atic technique for the prevention and treatment of mucositis of various ori gins. Preliminary findings, and significant results obtained for chemothera py-induced mucositis in a previous phase III study, prompted a randomized m ulticenter double-blind trial to evaluate LEL in the prevention of acute ra diation-induced stomatitis. Irradiation by LEL corresponds to local applica tion of a high-photon-density monochromatic light source. Activation of epi thelial healing for LEL-treated surfaces, the most commonly recognized effe ct, has been confirmed by numerous in vitro studies. The mechanism of actio n at a molecular and enzymatic level is presently being studied. From. Sept ember 1994 to March 1998, 30 patients were randomized. Technical specificat ion: 60 mW (25 mW at Reims, 1 patient), He-Ne, wavelength 632.8 nm. The tri al was open to patients with carcinoma of the oropharynx, hypopharynx and o ral cavity, treated by radiotherapy alone (65 Gy at a rate of 2 Gy/fraction , 5 fractions per week) without prior surgery or concomitant chemotherapy. The malignant tumor bad to be located outside the tested laser application areas (9 points): posterior third of the internal surfaces of the cheeks, s oft palate and anterior tonsillar pillars. Patients were randomized to LEL or placebo light treatment, starting on the first day of radiotherapy and b efore each session. The treatment time (t) for each application point was g iven by the equation : t (s) = energy (J/cm(2)) x surface (cm(2))/Power (W) . Objective assessment of the degree of mucositis was recorded weekly by a physician blinded to the type of treatment, using the WHO scale for grading of mucositis and a segmented visual analogue scale for pain evaluation. Pr otocol feasibility and compliance were excellent. Grade 3 mucositis occured with a frequency of 35.2% without LEL and of 7.6% with LEL (P < 0.01). The frequency of "severe pain" (grade 3) was 23.8% without LEL, falling to 1.9 % with LEL (P < 0.05). Pain relief was significantly reduced throughout the treatment period (weeks 2-7). LEL therapy is capable of reducing the sever ity and duration of oral mucositis associated with radiation therapy. In ad dition, there is a tremendous potential for using LEL in combined treatment protocols utilizing concomitant chemotherapy and radiotherapy.