Light & photobiomodulation
Photobiomodulation to Prevent Oral Mucositis
Graded on: severe (grade 3 to 4) oral mucositis during head and neck radiotherapy or chemoradiation and stem cell transplant, graded by blinded clinicians.
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How this letter has changedLatest: September 2026 · Added.
New device record under the Grade A rule as revised in September 2026, which counts a clinician-assigned outcome grade scored blind to treatment. Low-level light applied inside the mouth during head and neck radiotherapy or stem cell transplant cut severe mucositis in sham-controlled trials from independent groups in Brazil, India and the United States (Antunes et al., Radiother Oncol 2013; PMID PubMed ID: the permanent number the US National Library of Medicine gives a published paper. Each one links to that paper's record on PubMed. 24044799. Gautam et al., Radiother Oncol 2012; PMID 22884841. Hu et al., Support Care Cancer 2026; PMID 42360517), and the MASCC/ISOO guideline recommends it for prevention (Zadik et al., Support Care Cancer 2019; PMID 31286228). Not covered: treating sores already present, children, where trials found no benefit (Andriakopoulou et al., In Vivo 2024; PMID 38688628), and any US FDA clearance, since none exists for this use.PMID 24044799 PMID 22884841 PMID 42360517 PMID 31286228 PMID 38688628
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Photobiomodulation shines low-level laser light inside the mouth to prevent painful mouth sores during cancer treatment. In trials against fake light from teams in Brazil, India and the US, severe sores fell by about half or more. Patients also needed fewer opioid pain drugs and had fewer breaks in treatment. It did not help sores that had already formed, and trials in children found no benefit. Results varied a lot between trials. No device is cleared by the FDA for this use, and eye protection is standard during laser use.
A letter describes the human evidence, not the product, the manufacturer, or the intervention's worth.
See the full evidence record →Graded on Severe (grade 3 to 4) oral mucositis during head and neck radiotherapy or chemoradiation and stem cell transplant, graded by blinded clinicians.
Why this gradeThe reasoning, and what the grade does not cover.
Grade A under the rule as revised in September 2026, which counts a validated outcome scale scored by a clinician blinded to treatment. The mucositis grade is assigned by a clinician examining the mouth, and its top grades are partly functional: grade 3 means only liquids can be swallowed, grade 4 means nothing by mouth. Across sham-controlled trials from independent groups in Brazil, India and the United States, severe mucositis fell by roughly half or more, supported by fewer opioids and fewer treatment breaks, and the international MASCC/ISOO guideline recommends it for prevention.
WHAT THIS GRADE DOES NOT COVERtreating sores that have already formed (a phase III trial of treatment found no difference); children, where trials and a pooled analysis found no benefit; and chemotherapy alone outside transplant. Feeding tube use was not reduced significantly in the two trials that measured it. Heterogeneity How much the results of the pooled trials differ from each other. High heterogeneity makes a combined estimate less reliable. between trials is high, the largest trials come from one group in India, and most systematic reviews A review that searches for every study on a question using a method set in advance, then assesses them together. in this field are rated low quality. No device is FDA-cleared The FDA found a device substantially equivalent to one already on the market. Clearance is not approval and does not require trials showing benefit. for this use in the United States.
Shared endpoint The outcome a trial measures to decide whether the treatment worked, such as heart attacks, blood pressure or a symptom score.: Severe (grade 3 to 4) oral mucositis, clinician-graded, active versus sham A fake version of a procedure or device used as the comparison, so participants cannot tell which one they received. laser
- National Cancer Institute (INCA), Rio de Janeiro, Brazil (Antunes): Grade 3 to 4 mucositis 6.4 percent versus 40.5 percent with sham, head and neck chemoradiation. PMID 24044799 · Funding: academic
- Manipal University, India (Gautam): Fewer cases of severe mucositis, less pain and opioid use than placebo An inactive substitute made to look like the real treatment, so participants cannot tell which one they received., triple-blinded. PMID 22884841 · Funding: academic
What the replication does not cover: Laser parameters vary widely across trials.
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Treatment is off-label in the United States: no device is cleared by the FDA for this use. The guideline protocols are specific in wavelength, dose and timing, and other settings are not what this grade describes. Trials in children did not show benefit. Eye protection is required during laser use.
The evidence, in full14 papers, each linked to its PubMed record.
Antunes et al. (Radiother Oncol, 2013; PMID 24044799): 94 patients on chemoradiation for head and neck cancer, double-blind Neither the participants nor the people assessing them know who received the real treatment until the trial ends. placebo-controlled; grade 3 to 4 mucositis 6.4% versus 40.5%. Gautam et al. (Radiother Oncol, 2012; PMID 22884841): 221 patients, triple-blind sham; severe mucositis, swallowing pain and opioid use all reduced. Gautam et al. (Oral Oncol, 2012; PMID 22502814): 121 patients; severe mucositis 29% versus 89%, treatment breaks 0% versus 9%. Ferreira et al. (Support Care Cancer, 2016; PMID 26248655): 35 stem cell transplant patients; severe mucositis 17.6% versus 61.1%. Silva et al. (Photomed Laser Surg, 2011; PMID 20969443): 42 transplant patients. Schubert et al. (Support Care Cancer, 2007; PMID 17393191): 70 transplant patients; 650 nm reduced severity, 780 nm did not. Hu et al. (Support Care Cancer, 2026; PMID 42360517): 85 patients at 12 US sites, intraoral LED device, double-blind sham; grade 3 or higher 36.8% versus 57.1%. Shen et al. (Head Neck, 2024; PMID 38265122): meta-analysis A study that pools the numbers from several trials into one combined estimate. of 14 trials, 869 patients; severe mucositis risk ratio 0.45. Chan et al. (Semin Oncol Nurs, 2023; PMID 36935333): transplant meta-analysis, 18 trials. Zadik et al. (Support Care Cancer, 2019; PMID 31286228): MASCC/ISOO guideline recommending prevention protocols. Kept in the record: Legoute et al. (Radiat Oncol, 2019; PMID 31118057), treatment of established sores rather than prevention, no difference; Cruz et al. (Pediatr Blood Cancer, 2007; PMID 16862549) and Andriakopoulou et al. (In Vivo, 2024; PMID 38688628), no benefit in children; Rodrigues et al. (BMC Oral Health, 2024; PMID 39294629), most systematic reviews in this field rated critically low quality.
Oral mucositis grade (WHO or NCI scale) assessed by the treating team at each visit through the course of radiotherapy or transplant, plus opioid use, feeding tube placement and unplanned treatment breaks.
Evidence notes: randomized trial, meta-analysis
Endpoint graded: Severe (grade 3 to 4) oral mucositis during head and neck radiotherapy or chemoradiation and stem cell transplant, graded by blinded clinicians (clinician_rated)
Last reviewed: September 2026
Educational use only · Not medical advice · EBL grades published human evidence and does not recommend treatment. Stopping a prescription is a decision for your physician.
As studiedDose, form, population and duration for every use.
Home red-light devices are sold for mouth sores; this grade describes clinician-applied prevention protocols during cancer treatment only.
A grade describes the intervention that was tested. Where the product on the shelf differs from it, this says so.
Primary evidence14 papers, each linked to its PubMed record.
Antunes et al. (Radiother Oncol, 2013; PMID 24044799): 94 patients on chemoradiation for head and neck cancer, double-blind placebo-controlled; grade 3 to 4 mucositis 6.4% versus 40.5%. Gautam et al. (Radiother Oncol, 2012; PMID 22884841): 221 patients, triple-blind sham; severe mucositis, swallowing pain and opioid use all reduced. Gautam et al. (Oral Oncol, 2012; PMID 22502814): 121 patients; severe mucositis 29% versus 89%, treatment breaks 0% versus 9%. Ferreira et al. (Support Care Cancer, 2016; PMID 26248655): 35 stem cell transplant patients; severe mucositis 17.6% versus 61.1%. Silva et al. (Photomed Laser Surg, 2011; PMID 20969443): 42 transplant patients. Schubert et al. (Support Care Cancer, 2007; PMID 17393191): 70 transplant patients; 650 nm reduced severity, 780 nm did not. Hu et al. (Support Care Cancer, 2026; PMID 42360517): 85 patients at 12 US sites, intraoral LED device, double-blind sham; grade 3 or higher 36.8% versus 57.1%. Shen et al. (Head Neck, 2024; PMID 38265122): meta-analysis of 14 trials, 869 patients; severe mucositis risk ratio 0.45. Chan et al. (Semin Oncol Nurs, 2023; PMID 36935333): transplant meta-analysis, 18 trials. Zadik et al. (Support Care Cancer, 2019; PMID 31286228): MASCC/ISOO guideline recommending prevention protocols. Kept in the record: Legoute et al. (Radiat Oncol, 2019; PMID 31118057), treatment of established sores rather than prevention, no difference; Cruz et al. (Pediatr Blood Cancer, 2007; PMID 16862549) and Andriakopoulou et al. (In Vivo, 2024; PMID 38688628), no benefit in children; Rodrigues et al. (BMC Oral Health, 2024; PMID 39294629), most systematic reviews in this field rated critically low quality.
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