Red Light Therapy for Radiation Dermatitis: Scientific Evidence

Whether photobiomodulation can lessen how severe radiation dermatitis becomes was examined in a 2024 review from India. The review covered 14 studies using wavelengths from 600 to 1100 nm, in which the therapy had been used for prevention alone, for treatment and management, or for both. 12 of the 14 reported a benefit with no adverse effects, while 2 found no significant effect on the reaction. The therapy appeared reliable for reducing severity, though the review called for more work on long-term effects, on pain and on quality of life.

Researchers in Brazil reviewed the evidence on photobiomodulation therapy for radiation burns in women treated for breast cancer. Their 2022 systematic review covered 286 patients drawn from 5 databases with no date limit, and 2 reviewers rated the quality of each study. Only women over 18 who received three-dimensional or intensity-modulated radiotherapy were included. The studies used red and infrared light, at device power from 0.08 to 1.1 W in continuous mode and 25 W in pulsed mode, giving doses of 3 and 4 J/cm². The authors concluded that photobiomodulation can reduce how severe the reaction becomes, while noting how few studies cover this body site and how much their methods varied.

Published in 2022, this observational study from Brazil followed 1 patient undergoing chemoradiotherapy for anal cancer. Radiation dermatitis had developed in the anal area, and the patient was given 620 to 780 nm light 8 times a week over 28 days. Light therapy appeared to work, both easing the symptoms and keeping the reaction in check, the authors reported. They also noted that no settled treatment exists for this reaction.

A 2021 systematic review and meta-analysis pooled 7 clinical trials to assess photobiomodulation therapy for radiation dermatitis. The trials used wavelengths from 590 to 905 nm at 44.6 to 168 mW/cm² and doses of 0.15 and 4 J/cm², in sessions from 35 seconds to 12 minutes across courses of up to 49 days. According to the analysis, breast cancer patients given the therapy developed more mild reactions than the comparison groups did. The therapy did, however, cut the most severe grade significantly. The reviewers rated the certainty of the evidence for prevention as very low and called for more randomized trials.

Moderate to severe reactions fell by 49% by the end of radiotherapy in the light therapy group, in a 2021 randomized trial of photobiomodulation for acute radiation dermatitis. 46 patients being treated for head and neck cancer received 808 and 905 nm light at 168 mW/cm² and 4 J/cm² in 5- to 10-minute sessions across 49 days. The trial reported this as the first randomized controlled trial in head and neck cancer patients to show photobiomodulation preventing severe reactions. Its authors recommended adopting the approach in radiotherapy practice.

According to a 2020 narrative review from Belgium, 9 clinical trials covering 534 patients have tested photobiomodulation therapy for acute radiation dermatitis. Those trials used wavelengths from 590 to 905 nm at irradiances between 44.6 and 590 mW/cm² and doses between 0.15 and 37.5 J/cm². The review reported that photobiomodulation appeared to reduce the severity of the reaction and the discomfort and pain that come with it. The authors concluded that it may be effective for both prevention and management, while noting that more research is needed to confirm the finding.

33 patients (ages 19 to 79) who recieved light therapy alongside a high dose of radiotherapy completed 90.6% of their planned sessions, in a 2020 clinical trial of photobiomodulation for radiation burns. All were due for a high radiotherapy dose to the neck. They had 590 and 830 nm light at 100 mW/cm² and 60 J/cm² in 11-minute sessions, 3 times a week, with 2 dermatologists and a radiation oncologist grading the skin. 13 of the 33 developed weeping skin, and only 3 reached the worst grade, which the authors called favorable as compared to earlier studies. No side effects appeared, though the study was built to test practicality rather than to settle whether the therapy works.

Doses of 35.71 and 27.77 J/cm² were delivered by 2 different diode lasers, in a 2020 observational study of 2 patients whose radiotherapy had caused severe acute radiation dermatitis on the neck that drug treatment had failed to settle. Red light at 660 nm was applied daily, in contact and at right angles to the skin, over 6 days for 1 patient and 9 days for the other. 1 laser ran at 100 mW over a 0.028 cm² beam for 10 seconds per point, the other at 40 mW over a 0.036 cm² beam for 25 seconds per point, delivering 1 J per point across the whole affected area. Healing improved markedly, and the pain that comes with the reaction eased, the researchers reported. They cautioned that randomized controlled trials are still needed to establish what the treatment can do.

Across 7 clinical trials covering 782 patients, a 2019 review examined photobiomodulation therapy for acute radiation dermatitis. The trials used the therapy both to prevent the reaction and to treat it once it appeared, at wavelengths from 590 to 970 nm and doses from 0.15 to 6 J/cm². Researchers found that it reduced the number of severe reactions, eased the pain that goes with them, and improved quality of life. They also reported that it seemed to be well tolerated by people undergoing cancer treatment.

60 people with head and neck cancer took part in a 2018 randomized trial in China of red light phototherapy for radiation dermatitis. 30 received routine daily care during radiotherapy, while the other 30 also received red light at 600 to 700 nm for 10 minutes twice a day until radiotherapy ended, with skin and pain assessed daily. The trial found that reactions in the red light group were mostly absent to moderate, while those in the routine care group were mostly moderate to severe, a statistically significant difference. Pain rose over time in both groups but was significantly lower in the red light group at weeks 2, 3, and 4.

Comparing laser therapy with a placebo device, a 2018 randomized trial in Belgium tested photobiomodulation to prevent acute radiation dermatitis. 120 breast cancer patients on an identical radiotherapy plan after lumpectomy were split evenly. 60 had 808 and 905 nm light at 168 mW/cm² and 4 J/cm² twice a week over 49 days, given straight after each radiotherapy session, and 60 had the placebo. Skin reactions did not differ early on, but by the end, 30% of the placebo group had reached a moderate or worse reaction, against 6.7% of the laser group. Quality of life scores also appeared better in the laser group.

This 2017 review examined how to prevent and manage skin reactions to radiotherapy, both the early kind and the kind that appears months or years later. It drew on published work rather than new patients, and covered low-level laser therapy (LLLT), vascular lasers, and skin care products, with doses between 9 and 11.5 J/cm². The authors concluded that there is evidence for photobiomodulation to both prevent and treat early radiation burns, and that a pulsed dye laser can clear the small visible blood vessels that mark the later form. They also noted that treatment of these reactions is in its infancy and that the evidence is not yet sufficient to support formal recommendations.

22 of 25 patients given light therapy developed only a mild skin reaction, in a 2017 clinical trial of photobiomodulation for the dermatitis that radiotherapy itself causes. All 70 were consecutively treated breast cancer patients having radiotherapy after breast-conserving surgery, with 25 given 660 and 850 nm light at 44.6 mW/cm² and 0.15 J/cm² twice a week alongside the radiotherapy course, and 45 given radiotherapy alone. According to the study, 3 of the light therapy group reached a moderate reaction and none a severe one, while in the comparison group 18 reached moderate and 2 severe. 15 of the 25 given light therapy reported no pain at all, against 13 of the 45 in the comparison group. Because the groups were not randomly assigned, the researchers also drew a matched set of 25 from the comparison group for a further comparison.

79 patients who received identical radiotherapy after lumpectomy took part in a 2016 clinical trial of laser photobiomodulation for acute radiation dermatitis. All 79 received standard skin care, and 38 of them also had 6 laser sessions at 808 and 905 nm, 168 mW/cm² and 4 J/cm², starting at the twentieth dose of radiotherapy. Skin damage was similar in both groups before the laser began, but differed sharply by the end. 29% of the comparison group reached a moderate reaction, against 3% of the laser group. Patients rated the laser more favorably than skin care alone, though quality of life scores did not differ.

When researchers tested light therapy on a shortened radiotherapy schedule, the benefit fell short of significance. This was a 2022 randomized trial in Belgium of photobiomodulation for acute radiation dermatitis in breast cancer. 71 patients received either 808 and 905 nm light at 168 mW/cm² and 4 J/cm² twice a week over 28 days, or the control routine. By the last session, 10% of the light group had a moderate reaction and none a severe one, against 28% with moderate or severe in the control group. That 18% drop appeared to favor light therapy but did not reach statistical significance.

No difference in skin reactions appeared between the treated and sham groups in a 2010 randomized double-blind trial of LED photomodulation for preventing radiation dermatitis. 33 patients in the United States, treated for breast cancer after surgery, received either LED or a sham treatment alongside radiotherapy in 35-second sessions. Among the 18 given LED, 6 had a mild reaction and 12 a moderate one, with none severe. Among the 15 given sham, 1 had no reaction, 4 mild, 9 moderate, and 1 severe. The trial found that LED reduced neither the skin reactions nor the breaks in radiotherapy.