Rojas G. et al. - Photobiomodulation and Oral Mucositis Induced by Cancer Treatments: A Systematic Review and Meta-Analysis

In 7 randomized trials published since 2020 involving 329 patients undergoing chemotherapy or radiation therapy, photobiomodulation was associated with a reduced risk of oral mucositis (RR 0.50, 95% CI 0.35 to 0.73). It is used here as supportive care and has no effect on the cancer itself.

What this study measured

Oral mucositis is one of the most feared complications of cancer treatment. It causes inflammation and ulcers of the oral mucosa, which can make eating difficult, require strong pain medication, and sometimes lead to the interruption of the cancer treatment regimen.

This systematic review and meta-analysis was deliberately limited to randomized clinical trials published over the past six years, in order to reflect the photobiomodulation protocols currently in use. Seven trials were included, involving a total of 329 patients receiving chemotherapy, radiation therapy, or both. The primary outcome was the occurrence or severity of oral mucositis, for both prevention and treatment.

Key Findings

The reported benefit is net, and heterogeneity remains moderate, which is rare in this field.

• Relative risk of oral mucositis: 0.50 (95% CI 0.35–0.73) in favor of photobiomodulation
• Heterogeneity across studies: I² = 40%, described by the authors as moderate
• Wavelengths used: 635 to 980 nm
• Most common wavelength for intraoral use: 660 nm
• Intraoral application time: 3 to 20 seconds per spot
• Number of trials and patients: 7 randomized trials, 329 patients

The authors report a low risk of bias in the included trials and do not detect any significant publication bias.

How photobiomodulation works for this indication

The explanation generally put forward is twofold. On the one hand, low-intensity red and near-infrared light is absorbed at the mitochondrial level, which is thought to support the metabolic activity of epithelial cells subjected to the stress of treatment. On the other hand, an effect on local inflammatory mediators is thought to reduce the intensity of the mucosal reaction.

It is important to be clear about the scope: photobiomodulation is used here as an adjunctive therapy. It is intended to mitigate an adverse effect of cancer treatment and is not a treatment for cancer. The question of whether it might stimulate residual tumor cells remains a subject of debate in the literature, which is why the indication must be determined by the oncology team.

Limits You Should Know

The number of patients remains small: 329 in total, spread across seven trials. Such a favorable finding in a small sample size requires confirmation in larger cohorts.

Variability in protocols is the second limitation explicitly highlighted by the authors. Wavelength, application site (intraoral or extraoral), exposure duration, and number of sessions differ from one trial to another. The pooled results therefore do not allow for the identification of an optimal protocol, nor do they allow for the direct transfer of parameters from one trial to another clinical setting. Finally, the types of cancers and treatment regimens are not consistent across the studies.

What This Means in Practice

Photobiomodulation is already included in several international guidelines on supportive care in oncology for the prevention of oral mucositis. This recent review supports this view and updates the assessment of its benefits using current protocols.

Implementation is the responsibility of the healthcare team: it requires a schedule of sessions coordinated with cancer treatments and equipment suitable for intraoral application. No patient should modify or interrupt their cancer treatment based on these results.

Frequently Asked Questions

Does photobiomodulation treat cancer?

No. In this study, it is used exclusively as supportive care to reduce oral mucositis caused by chemotherapy or radiation therapy. It has no established effect on the tumor.

By how much is oral mucositis reduced?

The reported relative risk is 0.50 (95% CI 0.35 to 0.73), representing a 50% reduction in risk compared with the control groups, based on 329 patients and 7 randomized trials.

Which photobiomodulation protocol is recommended?

The trials use wavelengths ranging from 635 to 980 nm—most commonly 660 nm for intraoral treatment—with treatment durations ranging from 3 to 20 seconds. This variability makes it impossible to establish a standard protocol, which must be defined by the oncology team.

Reference

Rojas G, Escalante-Parra R, Duarte A, Terán-Ángel G, Moreno-Garces P, Silveira FM, Sanchez-Ramirez C. Photobiomodulation for the treatment and prevention of chemotherapy- and/or radiotherapy-induced oral mucositis in cancer patients: a systematic review and meta-analysis of randomized clinical trials published in the last six years. Supportive Care in Cancer, 2026. PMID 42098536. PubMed link

This summary is provided for informational purposes only and does not constitute medical advice. Photobiomodulation is not a substitute for prescribed treatment. Consult a healthcare professional.