Evaluation of Prophylactic Photobiomodulation Therapy in Patients With Osteosarcoma Undergoing High Doses of Methotrexate

This is a phase 3, randomized study, with patients diagnosed with osteosarcoma, enrolled at national cancer institute in Brazil (INCA), candidates for the Glato protocol (chemotherapy with doxorubicin, cisplatin, methotrexate and surgery). Patients will be randomly randomized in permuted blocks to groups 1 or 2. After confirming the eligibility criteria, patients will be invited to participate in the research before starting treatment and the TCLE/TALE will be applied in accordance with the Good Clinical Practice Guide and national ethical standards.

After signing the TALE/TCLE, patients will be instructed to perform oral hygiene after all meals, solid or liquid, with fluoridated toothpaste. On the first day of chemotherapy, in addition to the oral hygiene protocol, patients will be instructed to rinse their mouth twice a day with 0.12% chlorhexidine for 7 days. Once hyposalivation is diagnosed, patients will use oral humidifying gel four times a day (brand provided by the institution).

Photobiomodulation therapy

• Preventative photobiomodulation therapy will be performed with the MMO device (São Carlos, São Paulo, Brazil), with an indium gallium aluminum phosphide (InGaAlP) diode with radiation emission in the red region of the electromagnetic spectrum (660 nm) with power of 100mW, with a beam area of 0.03cm². An energy of 1J/point and an energy density of 33.3 J/cm²/point were determined, which will be applied punctually, with a distance between points of 1cm, for 10s per point, totaling 9 points per region .
• The technique will be performed on the first day of methotrexate infusion and until the patient reaches a serum concentration equal to or lower than 0.3 mmol/L; on the days of doxorubicin and cisplatin infusion and the day after; and on the days of infusion of doxorubicin alone in weeks 24 and 28 of the Glato protocol. Photobiomodulation will be performed in all cycles of chemotherapy treatment depending on patient randomization.
• Group 1- Preventive photobiomodulation will be carried out on the day of methotrexate infusion and until the patient reaches a serum concentration equal to or lower than 0.3 mmol/L, from weeks 4, 5, 9, 10, 17, 18, 22, 23 , 26, 27, 30 and 31). On the days of infusion of doxorubicin and cisplatin and doxorubicin isoleted, patients will not receive photobiomodulation therapy.
• Group 2- Preventative photobiomodulation will be carried out on the days of doxorubicin infusion (weeks 1, 6, 14, 19, 24 and 28) and cisplatin (weeks 1, 6, 14 and 19) and on the day after doxorubicin infusion and cisplatin (weeks 1, 6, 14, 19), on the days of infusion of doxorubicin isoleted, weeks 24 and 28, photobiomodulation will be performed only on the first and second day. The technique will also be performed on the day of methotrexate infusion and on subsequent days until the patient reaches a serum concentration equal to or less than 0.3 mmol/L, from weeks 4, 5, 9, 10, 17, 18, 22, 23 , 26, 27, 30 and 31).
• If the patient presents oral mucositis Grade 1, 2, 3 or 4, they will receive treatment with the MMO device (São Carlos, São Paulo, Brazil), with an indium gallium aluminum phosphide diode (InGaAlP) with radiation emission in the red region of the electromagnetic spectrum (660 nm) with a power of 100mW, with a beam area of 0.03cm². An energy of 2J/point and an energy density of 66.6 J/cm²/point were determined, which will be applied punctually, for 20s per point in the area with MO and in healthy areas.
• The regions treated with laser of the oral mucosa will be: right and left buccal mucosa, lower and upper lip, upper and lower labial mucosa, right and left lateral border of the tongue, lingual belly, floor of the mouth and soft palate.
• Assessment of the patient's oral mucosa will be carried out by members of the research project team.

Oral assessment