Non-thermal CO2 Laser Therapy (NTCLT): A Novel Photobiomodulative Approach for Immediate Pain Relief of Patchy Oral Mucositis Due to Chemotherapy of Solid Tumors

Introduction: Chemotherapy-induced oral mucositis (COM) is a prominent complication of chemotherapy (CT). Non-thermal CO2 laser therapy (NTCLT) has been demonstrated as an innovative and safe photobiomodulative approach in some kinds of painful oral lesions. The purpose of this study was to evaluate the palliative effects of one session of NTCLT on COM lesions. Methods: Patients with painful COM (WHO grade:≥2) were included in this before-after clinical trial based on the eligibility criteria. The oral lesions were irradiated with a CO2 laser (power: 1 W, scanning the lesions with the rapid circular motion of the defocused handpiece) through a thick layer (3-4 mm) of a transparent gel containing a high-water content. The severity of pain in the lesions was self-assessed using a 0-to-10 visual analogue scale (VAS) for 7 consecutive days. The evaluating physician visited the patients on the 3rd and 7th days in search of any kind of complications. Results: Seventeen adult patients with 35 patches of OM due to chemotherapy of solid tumors completed the trial. Immediately after NTCLT, the mean for non-contact VAS pain scores of the lesions significantly declined from 4.91±2.356 to 0.29±0.622 (P<0.001) and the mean for contact VAS pain scores from 7.77±1.57 to 1.31±1.18 (P<0.001). The mean VAS pain scores of the lesions showed statistically significant differences between the follow-up periods compared to the baseline (P<0.001). The process was completely pain-free and required no anesthesia. After NTCLT, no kind of thermal adverse effects such as irritation, destruction, aggravation and even erythema were observed. Conclusion: Based on the results of this before-after clinical trial, NTCLT has the potential to be considered as a non-invasive and safe palliative option for the pain management of patchy OM due to chemotherapy of solid tumors.