Integrating Photobiomodulation into Routine Care in the Absence of Guidelines: An Approach Based on Combining Available Data from the Literature with Clinical Experience

Abstract

Background:

The literature data suggests that it would be attractive to integrate photobiomodulation (PBM) into the routine management of patients in a variety of pathologies, although there are no practice guidelines to date on the indications for PBM use.

Objective:

This article presents an approach for rigorously developing medical treatment protocols for certain conditions that incorporate PBM in the absence of existing recommendations in five steps.

Method:

The first step is to determine how medical indications potentially eligible could be chosen, for example, diseases where current treatment options are not totally effective or satisfactory. The second step is to define the most appropriate PBM protocol. Experts have emphasized the need to adhere to several dosimetric parameters to ensure the effectiveness of PBM (wavelengths, fluence, irradiance, total dose, session frequency, etc.). The total energy dose delivered is of paramount importance. The third step is to choose scales to evaluate effectiveness and tolerability. The scale selected must be acceptable to the patient and informative to the operator regarding the effectiveness of the treatment by PBM. In the fourth step, the protocol must be designed to be integrated into daily practice without making it more burdensome. The final step is to objectively evaluate the protocol to decide on its relevance.

Conclusion:

At each stage, the assessment must be based on data published in the literature and expert opinions.

Introduction

Nowadays, the management of diseases is largely evidence-based and often based on guidelines from professional societies or other expert groups. However, there are still some situations where it may be legitimate to introduce new management strategies or technologies in the absence of professional guidelines. This should be done in compliance with the procedures described by Akobeng and the principles of evidence-based medicine ¹ (even when such evidence is lacking) and taking care to ensure the safety of the new methods.

Photobiomodulation (PBM), also previously known as low-level laser therapy, is a nonpharmacological treatment technique that involves applying specific nonionizing light wavelengths to tissues to promote positive biological effects (anti-inflammatory, analgesic, immunomodulatory, wound-healing promotion, etc.). ² With their low intensity (usually less than 500 mW), and primarily photochemical mechanism of action, PMB treatments generate a limited level of heat. The most commonly used wavelengths are red or near-infrared. PBM has been the subject of international guidelines for certain side effects of cancer treatments^3–5 or clinical consensus documents on the applications of PBM for other adverse effects of cancer therapy.^6,7 There is also a growing body of literature about PBM, and it has a wide spectrum of potential indications due to its mechanisms of action. An increasing body of literature attests to the beneficial effects of PBM in a variety of pathologies, although there are no practice guidelines to date on the indications for PBM use.

The literature data suggests that it would be attractive to integrate PBM into the routine management of patients, especially those suffering from diseases where current treatment options are not totally effective or satisfactory.

The aim of this article, therefore, is to present an approach for rigorously developing medical treatment protocols for certain conditions that incorporate PBM in the absence of existing recommendations (Fig. 1). We discuss how the indications are chosen, how to decide on the most appropriate PBM protocol, and how to evaluate practices with a view to implementing the protocol and deciding whether or not it is the most appropriate, both from the patient’s point of view and from the point of view of the technical PBM operator.

FIG. 1.

Overview of the methodology for implementing, in routine practice, protocols that incorporate photobiomodulation for medical indications, outside existing recommendations.

Step 1. Medical indications potentially eligible for the implementation of a protocol integrating PBM outside current recommendations

The indications for PBM in human medicine are numerous and rapidly expanding. ⁸ A search of PubMed using the terms (photobiomodulation OR low-level laser therapy OR low-level light therapy) yields several thousand articles, the majority of which were published in the last 5 years. This reflects the growing interest in this nonpharmacological technology. These publications cover a wide range of medical fields, from skin diseases to psychiatry, including ophthalmology,^9–13 to mention only articles published in 2025.

However, a search for the keywords “photobiomodulation AND recommendations” or “photobiomodulation AND guidelines” retrieves no articles. A search using the keywords “low-level laser therapy AND guidelines” or “low-level laser therapy AND recommendation” found only two articles,^14,15 of which one is actually a narrative review. The most frequently cited recommendations for PBM indications are those published in 2022 in a position paper based on work by the Cancer Supportive Care World Association for Laser Therapy (WALT) Working Group, ⁶ currently being updated, as well as those published in 2025 concerning stem cells. ¹⁶ These indications, developed by experts in supportive care, focus on the adverse effects of treatments administered in the context of cancer management (radiodermatitis, mucositis, xerostomia, dysphagia, trismus, lymphoedema, alopecia, etc.), and these recommendations as well as their practical applications have represented a major advance for patients undergoing cancer treatment.

Outside the supportive care indications developed by WALT^6,16 or issued by certain supportive care societies such as the Multinational Association of Supportive Care in Cancer and the International Society of Oral Oncology,^4,5 guidelines for the use of PBM outside oncology are rare, and the levels of evidence are limited. ⁷ A search for meta-analyses of PBM studies in PubMed (extraction dated 04/11/2025) identified 89 articles (using the filter “humans” and excluding cancer and supportive care indications).

The medical specialties most commonly concerned are dentistry and stomatology, musculoskeletal disorders (muscle recovery), dermatology (acceleration of wound healing in diabetic foot ulcers), and ophthalmology (age-related macular degeneration). The use of PBM in other fields is less well-documented, such as gynecology (with the exception of vulvodynia ¹⁷ ; e.g., endometriosis, symptoms related to peri- and menopause, pudendal neuralgia, or sequelae of brachytherapy), urology (e.g., bladder pain syndrome), chronic inflammatory diseases (e.g., ankylosing spondylitis, multiple sclerosis, rheumatoid arthritis, etc.), and neurology (migraine). Yet, the study of the pathophysiological mechanisms of a number of these conditions suggests a potential effectiveness of PBM in improving certain symptoms.

Step 2. Choice of the treatment protocol

Selecting the protocol is a critical step in PBM. Reviewing the existing literature is essential to determine the different parameters by comparing those used with the outcomes reported by authors. Experts have emphasized the need to adhere to several dosimetric parameters to ensure the effectiveness of PBM (wavelengths, fluence, irradiance, total dose, session frequency, etc.).^7,18,19 The total energy dose delivered is of paramount importance, and the time required to deliver this energy is also crucial. ¹⁹ In theory, these parameters can be derived using the following equation:

$$E\mathrm{\hspace{0.17em}}=P\mathrm{\hspace{0.17em}}\times \mathrm{\hspace{0.17em}}t/1000$$

where E = fluence in joules per cm²; P = irradiance in milliwatts per cm²; and t = time in seconds.

The therapeutic dosage is most often between 1 and 12 J/cm²,^6,20 but it can sometimes be difficult to measure the exact dose delivered to the target tissue when it is located deep, like the bladder or the brain. For target organs that are located at a depth, it is necessary to account for the penetration capacity according to the wavelength delivered and, where appropriate, whether the light source is pulsed or continuous, as well as its nature (LED or laser).^21,22 The benefit of using continuous versus pulsed light remains insufficiently documented to date. ²³ In certain indications, such as transcranial PBM (tPBM), alopecia, mucositis, radiodermatitis, or the healing of pressure ulcers, research has provided precise data on the wavelengths to be preferentially used and on the depth of penetration.^22,24 Systematic reviews have also enabled comparison of different protocols and the identification of the most effective parameters. ²⁵ When such information is not available, it is possible to work by analogy with a more common indication and to have the protocol validated by a panel of PBM experts. Sharing protocols encourages the exchange of experiences and helps compensate for the lack of information in the literature. Manufacturers of PBM devices cannot be considered a sufficient source of information due to potential conflicts of interest or due to incomplete or even erroneous scientific communications. The protocols proposed by PBM device manufacturers should be taken into consideration and analyzed in light of the information available in the scientific literature.

A further constraint in developing the PBM protocol is the need to take into account care-related practical issues, which include, on the one hand, availability of PBM equipment and, on the other hand, feasibility of the protocol within the consultation timeframe (available facilities, operator time, patient acceptability, ergonomics, etc.). Some protocols described in the literature are simply not reproducible in routine clinical practice. ²⁶

In addition, some devices are designed for a single target organ, such as endovaginal probes, whereas others offer greater versatility, sometimes at the expense of ergonomics or a longer administration time. Thus, for example, in tPBM, devices composed of triptych panels equipped with several programs provide greater versatility but have less congruent positioning than helmets. Here again, analysis of the literature can be extremely helpful. ²⁷ Aligning the technical platform and the technical professional skills with the indication is a key element of the potential therapeutic success.

Precautions to ensure the safety of the operator and patient must also be included in the treatment protocol. For example, the use of lasers requires eye protection with appropriate goggles.

Finally, care must always be considered as a whole, and PBM should be integrated into a holistic management strategy, especially in situations involving chronic symptoms. For example, in the case of bladder pain syndrome, it may be useful to include a patient education program (voiding diary, avoidance of substances that irritate the bladder). A care plan including cognitive remediation may also be considered when screening reveals associated anxiety–depressive syndrome. ³² The presence of anxiety can distort the assessment of the performance of a PBM intervention and must therefore be screened for beforehand. It may be useful to consult experts in the field before choosing an assessment tool to test its clinical relevance. The constraints associated with the administration of assessment tools must be compatible with the constraints of the consultation. Self-assessment tools have the advantage of not requiring the operator to be present during the completion phase.

Step 3. Choosing scales to evaluate effectiveness and tolerability

Given that PBM is an innovative medical practice, especially in routine care, evaluation (notably of safety, effectiveness, acceptability, etc.) is essential. Evaluation must be based on scales or scores that have been validated in the literature. The use of inappropriate scores can lead to erroneous measurement of certain disorders and underestimation of their frequency or intensity.^28,29 PBM interventions usually take place over a short period, such as a few weeks. ⁶ The assessment scale must take this timeframe into account and limit the possible “test–retest” effect. ³⁰ The scale selected must also be acceptable to the patient. Finally, it should assess a clinically relevant and, if possible, objective criterion. Dual assessment (i.e., both self-assessment and observer-rated assessment) can be considered if the PBM operator has received specific training. Measuring anxiety and depression is often a useful complement. Numerous studies have shown an association between anxiety and perception of pain, ³¹ cognitive performance, ³² worsening functional decline, ³³ and even an individual’s perception of how they move. ³⁴ The presence of untreated anxiety may bias the evaluation of the PBM intervention’s performance and, therefore, should be screened for beforehand and treated where necessary. It may be useful to consult experts in the field before choosing an assessment tool to test its clinical relevance. The constraints of doing the assessment must be compatible with the constraints of the consultation. Self-assessment tools have the advantage of not requiring the presence of the operator while they are being completed.

Step 4. Implementing the protocol in practice

Implementing a care protocol that is not supported by strong scientific recommendations requires two precautions. The first is patient safety. The arguments in favor of the safety of PBM use are numerous and consistent.^6,7,35 To date, no evidence supporting pro-carcinogenic activity of PBM has been published in the clinical literature. ³⁵ In fact, prevention of the adverse effects of cancer treatments is the area where the recommendations for PBM are currently the most well established.^6,20,36–38

The second precaution relates to the attention given to the outcomes of the protocol and to its actual implementation. Tissot-Dupont et al. ³⁹ reported that treatment recommendations for the management of infective endocarditis were followed in only about 58% of cases, according to a survey of a diverse panel of physicians, including the physicians who had actually written the recommendations themselves. When introducing PBM into routine clinical situations that are outside of currently existing guidelines, particular care must be taken to ensure strict adherence to the protocol to generate high-quality data suitable for analysis. Training of all stakeholders involved in the protocol is a crucial step. They must have full mastery of the clinical context (i.e., the condition or symptom targeted by the PBM), the technical skills (handling of the devices delivering PBM), and the protocol evaluation (proper use of scales or scores).

Step 5. Evaluation of the care protocol

This final step is crucial. It must comply with the standards of scientific evaluation and result from objective, uncompromising analysis. It should make it possible to confirm or refute the value of the PBM protocol, specify the target population or symptom, and provide guidance for possible modifications (fluence, wavelength, positioning, frequency, etc.) based on the available data. The viewpoints of all stakeholders in the care environment (e.g., health care professionals, technicians, and patients) must be taken into account. Throughout the process, each stakeholder must respect their role and contribute honestly and transparently to data collection. The person who initially drafted the care protocol should not be the person who selects patients eligible for PBM treatment. Eligible patients must be identified using objective eligibility criteria. The caregiver who applies the protocol and collects the data during routine care should not be the one to perform the analysis of the data thus obtained. Further, the analysis protocol that forms the basis for evaluating the care protocol should be written and finalized before data collection begins. Finally, the patient’s feedback about their overall experience should be solicited and noted. Under these conditions, the data collected, the analyses performed, and their interpretation will provide robust insights into the relevance of the PBM-based care protocol. In addition, in accordance with best practices for clinical research, the conclusions drawn from the work should be published to advance the scientific knowledge pertaining to PBM, even when the results are considered unfavorable.

Conclusion

The absence of recommendations can be seen as a barrier to implementing PBM in routine care. However, respecting a few basic rules makes it possible to overcome this limitation, even in the context of an innovative technique. The implementation of a routine care protocol encompassing PBM must be based on clinical and scientific principles that respect existing knowledge. ⁴⁰ PBM may be considered a stand-alone or complementary therapeutic option in situations where current treatments are unsatisfactory, have failed, are difficult to access, and/or are associated with major adverse effects; when the underlying pathophysiological mechanisms of the symptom are known; and when there is a strong parallel between these mechanisms and the established mechanisms of action of PBM.

When relevant, it is important to integrate PBM into a multi-modal management strategy combining pharmacological approaches, interventional techniques (including surgery and radiology), and complementary approaches (such as adapted physical activity). The creation of working groups that include experts in both the targeted pathology and PBM could facilitate the development of more effective protocols.

Authors’ Contributions

L.G.: Conceptualization, methodology, validation, writing original draft and review and editing, visualization, supervision, and project administration. H.D.: Validation, writing original draft and review and editing, visualization, supervision, and project administration. A.L.: Validation, writing original draft and review and editing, visualization, and supervision. M.D.: Validation, writing original draft and review and editing, visualization, supervision, and project administration.