Photobiomodulation therapy in breast cancer-related acute radiodermatitis cases in Brazilian women: study protocol for a randomized controlled trial

Abstract

Background

Radiodermatitis is one of the most common radiotherapy-related side effects, which can influence patients’ quality of life and affect therapeutic efficacy. Photobiomodulation therapy (PBMT) appears as a low-cost technology, with significant results in the tissue repair process.

Methods

It is a triple blind randomized controlled trial. A total of 96 patients undergoing radiotherapy for breast cancer are estimated for the sample, which will be randomly assigned to a control group to receive a placebo and the institution’s standard protocol (n = 48) or to an intervention group to receive PBMT, in addition to standard therapy (n = 48). The intervention consists of applying Laser Therapy EC (DMC™, São Carlos—SP, Brazil), with power of 100mW, continuous emission mode, red wavelength (660 ± 20 nm), fluence of 10.16 J/cm², and energy of 1 J per point, three times a week since day one, right before the radiotherapy session. Blinding will be applied to patients, evaluators, and the statistician. Skin reactions will be assessed weekly using the Acute Radiation Morbidity Scoring Criteria developed by the Radiation Therapy Oncology Group and thermal images of the irradiated area that will be captured. In addition, the impact of radiodermatitis on the quality of life will be assessed through the application of the Cancer Quality of Life Questionnaire (EORTC QLQ-30) and the Breast Cancer Quality of Life Questionnaire (EORTC QLQ -BR23) at the beginning and in the end of treatment. Data will be processed and analyzed by the statistical package R using descriptive and inferential statistics.

Discussion

Photobiomodulation stands out for being a non-invasive and low-cost therapy that has not been associated with adverse events. It used to stimulate wound healing by promoting tissue repair, by reducing inflammation, by stimulating collagen synthesis, and relieving pain. Cientific literature have been highlighted PBMT as an effective tool in preventing or reducing the severity of radiodermatitis and its associated symptoms, which expected to be demonstrated with this ongoing study.

Trial registration

Brazilian Clinical Trials Registry (ReBEC – Registro Brasileiro de Ensaios Clínicos) – Id. RBR-7gkw3d4; Universal Trial Number (UTN) – Id. U1111-1279–1686; Plataforma Brasil/Research Ethics Committee – Id. 5.788.390, registered on 24 August 2022. https://ensaiosclinicos.gov.br/rg/RBR-7gkw3d4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-025-09294-8.

Introduction

Background

Breast cancer is the second most common type of cancer in the world and the most common among women, with high mortality rates in Brazil [1]. Among the therapies used, radiotherapy (RT) stands out for its use of ionizing radiation applied in pre-calculated doses, which produces direct and indirect ionization events that damage the deoxyribonucleic acid (DNA) of tumor cells, preventing them from multiply or induce them to apoptosis, leading to inflammation and oxidative stress [2–4].

Despite the most advanced RT modalities, which allow greater penetration and concentration of ionizing radiation in the tumor, preserving the adjacent area as much as possible, adverse effects are still frequent, because the daily exposure to radiation, even in small doses, causes biochemical and cellular changes, with immediate and late damage to the tissue around the tumor [3]. The most common adverse effect related to RT is radiodermatitis (RD), which affects approximately 95% of patients treated for breast cancer [2].

The skin, as a highly proliferative organ, is very susceptible to radiation damage and toxicity, which can be enhanced by intrinsic and extrinsic factors to the patient, such as malnutrition, obesity, smoking, radiosensitization due to previous chemotherapy, RT scheme, and modality used, which includes total radiation dose, fractionation scheme, type of equipment used, and volume of tissue irradiated. Once irradiated, the skin already presents structural and functional changes that can be manifested as transient or progressive erythema, edema, hyperpigmentation, epilation, dry or moist desquamation, and even ulceration, which appear in a sustained manner from the second week of RT with cumulative doses above 20 Gy. Chronic effects may also occur, such as skin atrophy, telangiectasias, and fibrosis [5–9].

Management of this complication includes hydration measures and general skin care, including prevention with aloe vera or calendula-based creams, and treatment with topical corticosteroids, hydrocolloid dressings, and hydrogels, according to the clinical manifestation [5]. Adequate management of radiodermatitis is fundamental in the care of cancer patients, but there is still no gold standard described in the literature [5, 6, 9], as evidenced in the systematic review carried out by Rocha et al. [6], because the studies available in the literature are very heterogeneous, evaluating different topical treatments and dressings, in addition to those mentioned above, which makes specific recommendations for the prevention and management of skin reactions difficult.

An ideal agent for the prevention of radiodermatitis should mediate the repair of DNA damage or promote skin regeneration [9]. Thus, advanced treatments with hyperbaric oxygen therapy and photobiomodulation therapy (PBMT) have become promising for reducing the incidence and severity of radiodermatitis, when used at the appropriate dose. The equipment used in PBMT emits low-intensity non-ionizing radiation, with a power of less than 1 W (W), with a wavelength between 630 and 905 nm [10].

PBMT acts through the absorption of a specific wavelength by specialized photoreceptor molecules, called chromophores, triggering photochemical, photophysical, and photobiological effects in cells and tissues, which promote anti-inflammatory, analgesic, and tissue reparative action, inducing the synthesis of collagen and proliferation of fibroblasts, in addition to the bactericidal effect when associated with a photosensitizer, such as methylene blue [6, 10].

In oncology, it is widely used for the prevention and treatment of oral mucositis induced by chemotherapy or RT [11–14]. Other indications have been highlighted based on those evidenced in clinical trials, such as treatment for chemotherapy-induced peripheral neuropathy [15, 16], lymphedema, and radiodermatitis, without evidence of side effects associated with its use [10, 17].

Some clinical trials have been carried out to investigate the effect of PBMT in reducing the incidence and severity of radiodermatitis, with diverse results, including a significant reduction in the incidence and severity of skin toxicity [18–22] or absence of significant differences between control and intervention groups [23, 24], which can be justified by the variation in the technique used and the scheme adopted in each study.

Based on these studies, the hypothesis is raised that PBMT may represent a prophylaxis for radiodermatitis, as well as reduce its severity. Therefore, this randomized clinical trial was designed to evaluate the effectiveness of photobiomodulation therapy in prevention and control of radiodermatitis.

Objectives

The primary aim of this study is to evaluate the effectiveness of photobiomodulation therapy in reducing the occurrence and severity of breast cancer-related acute radiodermatitis in women, compared to standard therapy. Secondary objectives consist in comparing tissue changes through temperature variation, symptoms, and health-related quality of life, according to the groups.

Methods: participants, intervention, and outcomes

Trial design and setting

This is a triple blind, two parallel group, randomized controlled clinical trial, that will be developed in a public cancer treatment reference hospital in the city of São Luis, Maranhão, Brazil, which will compare the institutional standard radiodermatitis prevention and treatment protocol with a photobiomodulation therapy application during the radiotherapy treatment.

Eligibility criteria

Inclusion criteria

This study included female patients older than 18 years old with a histological diagnosis of breast cancer (stages I to III) who underwent breast surgery, conserving, or mastectomy with or without breast reconstruction, with proposed adjuvant or neoadjuvant radiotherapy according to the clinical protocol of the hospital.

Exclusion criteria

Patients who have undergone prior irradiation of the area, who are undergoing concomitant chemotherapy, who present postoperative complications (such as surgical wound dehiscence or the presence of a seroma), will be excluded from the study, and women with a malignant neoplastic wound or the presence of dermatoses in the area to be irradiated.

Who will take informed consent?

Eligible candidates will be invited to participate in the study by the researchers. If they agree, they will be signing the free, written, informed consent form (FICF), and an interview with initial evaluation will be carried out.

Group assignment

All patients undergoing radiotherapy for breast cancer will be assessed for eligibility criteria immediately after the radiotherapy planning. Eligible patients will be informed about the study and invited to participate. A total of 96 patients undergoing radiotherapy for breast cancer (stages I to III) will be prospectively enrolled after providing informed consent. The participants will be allocated to an intervention group (IG—photobiomodulation, n = 48) or a to a control group (CG—placebo, n = 48). This second group will receive treatment from an inactivated laser unit that does not deliver radiation.

Regarding oncological treatment, all patients will follow the regular radiotherapy protocol for breast cancer adopted by the hospital, which consists in the application of three-dimensional radiation therapy (3D-RT), in a hypofractionation regime, applying 15 fractions (Fr) of radiation five times a week (daily therapeutic dose of 270 cGy and total dose of 4005 cGy), with or without the possibility of adding a dose reinforcement (boost) of 810 cGy divided into 3Fr, depending on the staging and margin compromise evidenced during surgery (in this case, total dose of 4815 cGy). In addition to the breast or plastron area (in those undergoing mastectomies), the axilla and supraclavicular fossa (SCF) regions will be included in the volume of tissue to be treated for cases with lymph node involvement.

Interventions

Explanation for the choice of comparators

Both control and intervention group will receive the standard skin care institutional therapy that consists in general measures to minimize the impact on irradiated skin, such as avoiding hot and cold baths or thermal compresses, keeping the skin dry and hydrated, avoid lightning and irritating agents, such as deodorants, perfumes, and cosmetics, wear light-colored clothing, use accessories for sun protection, such as hats and scarves, not shave armpits with razors or depilatory wax, avoid metal-based topical products (such as zinc or aluminum), and avoid heat sources when doing household chores or at work.

In addition to these general measures, the use of compresses is recommended at room temperature with chamomile tea and topical application of moisturizer based on vitamin A (0.5%) + aloe vera (25%) + sunflower oil (5%) + water-soluble base cream (60 g), massaging the area lightly until completely absorbed, at least twice a day.

Intervention description

Patients from the intervention group

To apply the laser, the Therapy EC device (DMC™, São Carlos—SP, Brazil) will be used, with an active solid laser diode medium (Gallium-Aluminum Arsenate—Ga-Al-As), presenting a spot with a diameter of 3.54 mm and area of 0.09842cm², power of 100mW (0.1W), continuous emission mode, and power density of 1.016W/cm². The red wavelength (660 ± 20 nm), fluence of 10.16 J/cm², and energy of 1 J per point will be adopted.

The application of the laser will occur through superficial contact, with a punctual technique, considering a space of 1 cm between the application points. It will be applied three times a week, on alternate days, before the radiotherapy session, throughout the proposed treatment. The time for application at each point, considering the energy adopted, is 10 s. Therefore, the total time will depend on the breast volume and the extent of the treatment area. In general, 30 min were allocated to each patient for the implementation of the intervention.

The parameters were adopted for both women with breasts and women with plastrons, as the wavelength selected (660 ± 20 nm) tends to disperse the laser energy more, being absorbed superficially, with penetration depth at the level of epidermis and dermis, in cases with a preserved skin barrier, with action focused on repair [16].

Patients from the control group

For CG, the same procedure will be performed without activation of the laser. However, the appearance and noise of this placebo will be identical to the treatment group. In addition, both groups of patients will be blindfolded and will wear protective goggles during the treatments.

Criteria for discontinuing or modifying allocated interventions

Loss to follow-up will only occur in cases of:

• Unjustified absence from treatment, participant withdrawal, hospitalization due to an oncological emergency;

• Death during the research;

• Presence of radiodermatitis grade 3 or 4 that indicates the interruption of RT until the wound improves;

• For the RD cases that will not interrupt RT sessions, the laser can be use if the service team requests it; however, it will be a criterion for discontinuing as a research participant due to loss of control, as all patients need to have the same time schedule and estimated dose to avoid generating bias in the study.

Strategies to improve adherence to interventions

With the aim of improving adherence to treatment, volunteers will have free access to the responsible researcher to clarify any doubts or report any symptoms other than those expected. Furthermore, the service team, including radiotherapist, medical physicist, and nurses, were well oriented about the research flow and contributed to the study, calling patients to apply radiotherapy only after the laser application/simulation.

Relevant concomitant care permitted or prohibited during the test

Patients are advised to perform only the skin care recommended by the institution, being contraindicated the use of any other product or skin treatment that may interfere with the results.

Provisions for post-trial care

Patients are treated with laser only during the radiotherapy. In general, 1 week after the end of treatment, an evaluation is carried out by the radiotherapist, and, in the absence of intense side effects, patients are advised to keep their skin care routine, especially in relation to sun exposure and skin hydration. Then, they are discharged from the radiotherapy service, and keep following up with clinical oncology and mastology.

In case of any changes in the skin that could be attributed to the treatment or intervention within 90 days following the patient’s discharge from the radiotherapy service, study patients are advised to contact the main researcher via telephone or WhatsApp to inform them. If they require additional skin treatment due to ongoing symptoms, they will receive the institution’s standard treatment. The laser can be use only if the service team requests it.

Outcomes

Primary outcome

Acute radiodermatitis

The primary outcome is assessment and grading of radiodermatitis. To identify and grade the acute effects of radiotherapy under the skin, the Acute Radiation Morbidity Scoring Criteria developed by the Radiation Therapy Oncology Group (RTOG) was used.

In 1982, the RTOG developed the criterion score for Acute Radiation Morbidity—Acute Radiation Morbidity Scoring Criteria, to classify the effects of radiotherapy. This criterion identifies grades 0 (no change over baseline), 1 (follicular faint or dull erythema, epilation, dry desquamation, decreased sweating), 2 (tender or bright erythema, patchy moist desquamations, moderate edema), 3 (confluent, moist desquamation other than skin folds, pitting edema), and 4 (ulceration, hemorrhage, necrosis) [25].

The presence of hyperpigmentation was also considered in the skin assessment, adopting the grading carried out by Schmidt et al. [5], which included the presence of mild hyperpigmentation in grade 1 reactions, and moderate to intense hyperpigmentation in grade 2 reactions.

Secondary outcomes

The secondary outcome is tissue changes, pain, and another skin-related symptoms and health-related quality of life.

Breast tissue features

These will be determined by means of thermography, a safe, non-invasive imaging method that determines the distribution of body surface temperatures according to physiological and pathological tissue conditions. Inflammation, metabolic subcutaneous tissue changes, and blood supply changes result in temperature gradient changes in the affected area [26].

The study participants will be instructed to remain in a standing position, without garments or other trunk accessories. Body surface temperatures will be recorded using a thermal camera in an upright position, with the arms behind the head. Frontal, lateral, and inframammary images will be captured on the ipsilateral and contralateral breast to radiotherapy (a total of six thermal images), at a distance of 1 m. The thermal images will then be analyzed using FLIR Tools/Tools + software.

Pain and skin-related symptoms

The characteristics of the changes presented by patients and complaints will be recorded. The assessment of local pain intensity will be done using the visual analogue scale, which varies from 0 to 10, including location, type, and duration of pain.

The visual analogue scale for pain was adapted and validated for use in Brazil by Ferraz et al. [27], in 1990. It is a patient self-evaluation scale, ranging from 0 to 10, with 0 meaning no pain and 10 meaning maximum pain [27].

Health-related quality of life

The health-related QoL will be assessed by using two European Organization for Research and Treatment of Cancer (EORTC) questionnaires.

Quality of Life Questionnaire Core 30

This comprises a specific questionnaire used to assess cancer patients. This instrument comprises 30 questions that derive from functional scales (physical functioning, role functioning, emotional functioning, cognitive functioning, social functioning), symptom/item scales (fatigue, nausea and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, diarrhea, financial difficulties), and global health status/QoL [28–30].

Quality of Life Questionnaire breast cancer-specific

This comprises a specific questionnaire to assess the quality of life of patients presenting breast cancer, consisting of 23 questions divided into functional scales (body image, sexual functional, sexual enjoyment, future perspective) and symptom/item scales (systemic therapy side effects, breast symptoms, arm symptoms, hair loss) [29–31].

Each scale of both questionnaires scores from 0 to 100. Higher scores in the functional and health-related quality of life (HRQoL) scales indicate a better quality of life, while higher scores in the symptom/item scales translate to a worse quality of life [32]. Both questionnaires have been translated into Portuguese and validated for the Brazilian population [33, 34].

Participant timeline

Figure 1 depicts the depicts the CONSORT flow diagram. Patients who meet the eligibility criteria are directed by the service’s nursing team, which schedules first-time patients. After the first consultation with a nurse and radiotherapist, patients are invited to participate in the study. After explanation and clarification of doubts, patients who agree to participate sign the informed consent form and are then interviewed regarding sociodemographic and clinical data.

Fig. 1.

CONSORT flow diagram

Sample size

The sample size was based on the study by Censabella et al. [21], which was the first clinical trial described in the literature, randomized and well controlled, with statistically significant results related to the use of photobiomodulation in women with breast cancer undergoing radiotherapy, in which radiodermatitis grade 2 or greater was observed in the control group in 30% compared to 6.7% in the intervention group. For this difference to be detectable in a chi-square test with a type I error of 5% and test power of 80%, it will be necessary to observe at least 96 patients, 48 in each group.

Recruitment

Recruitment is expected to last 12 months, because there will be only one professional to apply the intervention and one researcher to evaluate and collect data. Furthermore, the lack of appropriate physical space limits the scheduling of a larger number of patients. We plan to complete recruitment by July 2024.

Assignment of interventions: allocation

Sequence generation

After being recruited from the radiotherapy department of the hospital, indicated by the radiotherapist or the institutional nurse, the patients who agreed to participate in the study will be allocated in each group by randomly generated computer sequences by the Microsoft Excel program.

Concealment mechanism

Sequentially numbered, opaque, sealed envelopes containing the patient’s number in the study, which determines participant allocation in the intervention or control group, will be made available and opened just by the oncologic nurse responsible for the intervention.

Implementation

After recruitment, participants will sign the informed consent form together with the study researchers, and volunteers will be randomized into each arm of the study. The intervention will be applied from the first to the last day of RT, in a nursing room provided by the institution. Patients randomly assigned to be part of the GI will receive laser application, while the control group will receive simulated application.

Assignment of interventions: blinding

Who will be blinded

It is a triple blind study in which the patient will be blinded, such as the researcher responsible for the weekly skin evaluation, which is an internal medical student trained and qualified for this purpose, and the statistician responsible for analyzing the collected data. Only the researcher responsible for to apply the intervention will know the allocation of patients into the groups, which is a stoma therapy nurse qualified in photobiomodulation therapy.

Procedure for unblinding if needed

Due to the study characteristics, the research oncology and stoma therapy nurse responsible for the implementation of the intervention will be aware of the allocation groups. Consequently, no non-blinding procedure is planned.

Data collection and management

Plans for assessment and collection of outcomes

Clinical and demographic data will be collected before the first radiotherapy session, through interviews and medical record analyses. The interviews will consist of semi-structured questionnaires produced by the mainly researcher, which contains sociodemographic information, such as age, skin color, occupation, and marital status; clinical information, such as personal history, medications in use, weight and height, smoking, alcohol consumption, histopathological tumor type, molecular characteristics of the tumor, staging, and previous treatments; and data related to radiotherapy, which includes modality, doses, and treatment schedule.

To identify and grade the acute effects of radiotherapy under the skin, a physical examination will be carried out weekly, before the laser or placebo application, guided by the RTOG scale, and thermal imaging will be taken. Other reported symptoms, such as pain and other skin reactions will be registered. All participants included in the study will be evaluated until the end of the treatment, followed by discharge from the radiotherapy service, which occurs after completion of treatment in the absence of serious side effects. A detailed overview of all assessments can be found in Table 1.

Table 1.

Schedule of enrolment, interventions, and assessments

Study period
	Enrolment	Allocation	Post-allocation
Timepoint**	-t1	0	Week 1, fraction 1–5 (t1)	Week 2, fraction 6–10 (t2)	Week 3, fraction 11–15 (t3)	Week 4, fraction 16–18 (t4)
Enrolment:
Eligibility screen	X
Informed consent	X
Interview	X
Allocation		X
Interventions:
PBMT + standard protocol			X	X	X	X
PBMT simulation + standard protocol			X	X	X	X
Assessments:
Clinical data	X
Sociodemographic data	X
RTOG			X	X	X	X
Symptoms			X	X	X	X
Thermal images			X	X	X	X
EORTC-QLQ-30			X			X
EORTC-QLQ-BR23]			X			X

RTOG Acute Radiation Morbidity Scoring Criteria by Radiation Therapy Oncology Group, EORTC QLQ-30 EORTC Quality of Life Questionnaire, EORTC-QLQ-BR23 EORTC Quality of Life Questionnaire—Breast Cancer Module

The assessment of the impact of radiodermatitis on quality of life will be carried out on the first and last day of evaluation, after the end of treatment, for both intervention and control group, using the EORTC Quality of Life Questionnaire—EORTC QLQ-30 [28–30] and the EORTC Quality of Life Questionnaire—Breast Cancer Module – EORTC-QLQ-BR23 [29–31], both validated for the Brazilian population in oncologic treatment.

Plans to promote participant retention and complete follow-up

Study participants will receive the necessary information to understand the evaluation flow and the importance of completing the treatment. Any study participant can withdraw and leave the study at any time without necessarily explaining the reasons for it.

Data management

Data will be collected by an internal medical student, trained for skin evaluations and changes caused by radiotherapy, which will be filled on paper sheets and then, in electronic database, before exporting to statistical package R.

Statistical methods

Statistical methods for primary and secondary outcomes

The data will be processed and analyzed using the Statistical Package R program. A descriptive analysis of the sociodemographic and clinical characteristics of the study participant will be carried out through the distribution of absolute and relative frequencies for categorical variables and central tendency and dispersion measures for continuous variables. The thermographic analysis will be obtained by the average difference in temperatures of the breast who received and did not receive the radiotherapy before and after the treatment.

To compare groups with categorical data, the chi-square test or Fisher’s exact test will be used, while for groups with numerical data, the t-test or Wilcoxon-Mann–Whitney test will be used. The longitudinal assessment of the primary outcome will be carried out using the generalized mixed effects model (GLMM) for cumulative binomial family. To evaluate the mean score (with standard deviation), minimum, median, and maximum of the domains of the quality of life scales, the effect size and the magnitude of the Cohen effect will be used. A significance level of 5% will be accepted, at a confidence interval of 95%.

Methods for additional analyses (e.g., subgroup analyses)

There is no plan for subgroup analyses.

Methods in analysis to handle protocol non‑adherence and any statistical methods to handle missing data

Outcome assessments will be performed by intention to treat and protocol adherence will be verified. For missing data, the mixed effects model for repeated measures (MMRM) will be used.

Oversight and monitoring

Composition of the coordinating center and trial steering committee

This is a study developed in a single location and with few researchers involved. Therefore, no judging committee is included. All analyses of interim results and decisions regarding the conclusion of the study will be made by the main researcher.

Composition of the data monitoring committee, its role, and reporting structure

A data monitoring committee was not formed for this study. This decision was made based on the absence of serious adverse effects by the applied treatments, both in the experimental treatment and the control, which is the institution’s standard.

Adverse event reporting and harms

The occurrence and intensity of specific skin symptoms will be verified during the treatment. In addition, all participants will also be provided with a telephone contact that will serve as a communication channel between participants and researches for reporting adverse events, unpleasant symptoms, questions about ra.

Auditing

No audits were planned or contracted for this study.

Ethics and dissemination

Research ethics approval

Ethical Committees of the University of São Paulo and the Cancer Hospital Aldenora Belo have approved this study protocol (Id. 5.788.390). The study protocol was published in the Brazilian Clinical Trials Registry (ReBEC) with number RBR-7gkw3d4 and registered with Universal Trial Number (UTN) U1111-1279–1686. Only participants who agree to provide written informed consent will be enrolled.

Trial registration: RBR-7gkw3d4. Registered 22 August 2022, https://ensaiosclinicos.gov.br/rg/RBR-7gkw3d4.

Plans for communicating important protocol amendments to relevant parties (e.g., trial participants, ethical committees)

Any and all substantial changes that will affect the conduct of this research project will be communicated to the research ethics committee of the previously registered and approved institution for analysis and any judgment. In case the changes affect the participants in any way, they will also be informed about such changes.

Dissemination plans

The results of this study will be disseminated through indexed publications in peer-reviewed scientific journals and will also be presented to health professionals at national and international scientific events.

Consent for publication

Not applicable.

Availability of data and confidentiality

The data will be stored with the main researcher in case there is a need for revision or request by the ethics and research committee. All participants’ personal information will be kept confidential by main researcher, guaranteed by the free and informed consent form.

Discussion

Photobiomodulation stands out for being a non-invasive and low-cost therapy that has not been associated with adverse events. It is used to stimulate wound healing by promoting tissue repair, by reducing inflammation, by stimulating collagen synthesis, and relieving pain. Scientific literatures have been highlighted PBMT as an effective tool in preventing or reducing the severity of radiodermatitis and its associated symptoms [17–23, 35, 36], which expected to be demonstrated with this ongoing study.

Final results will provide data based on quantitative responses and self-reported results from participants. After analyzing the data, we hope to propose another modality for the treatment of this impactful condition in the care of cancer patients.

Strong points

This is the first study to comparatively evaluate the use of diode laser photobiomodulation versus traditional therapeutic resources applied to radiodermatitis in the Brazilian population. Furthermore, this study is a pioneer in the use of clinical thermography to evaluate characteristics of the breast tissue in the irradiated area.

Limitations

Due to the characteristics of this kind of study, this clinical trial is triple-blinded, but there is no possibility of blinding the nurse who is going to apply the intervention.

Administrative information

Trial status

This is the third version of the protocol (01/12/2022). Recruitment at the new institution began in July 2023, and it is ongoing. A total of 70 patients participated in the research so far. The time expected to complete the recruitment is about 12 months (until July 2024). Unfortunately, it was not possible to send the manuscript as early as desired due to delays in data collection related to several problems about the physical space used by the research team. As it was a public institution with few resources, the radiotherapy sector was small and only had three rooms that were rotated by the medical team and nurses. Thus, to carry out the intervention and follow-up of patients who participated in the research, a shared space was used in the brachytherapy post-anesthetic recovery room, which caused an important delay and reduced the number of patients who could be treated per day by the research.

Roles and responsibilities: committees

This is an investigator-initiated clinical trial. There were no committee involvement in the study’s design or in its execution. The entire coordination of the study was carried out by the main researcher, with constant frequency of alignment meetings for the development of the study.

Abbreviations

ANVISA

Agência Nacional de Vigilância Sanitária

CTC

Common toxicity criteria

cGy

Centigrays (dose administrated on radiotherapy)

3D-RT

Three-dimensional radiation therapy

mW

Milliwatts

NCI

National Cancer Institute

PBMT

Photobiomodulation therapy

RTOG

Radiation Therapy Oncology Group

Authors’ contributions

SRRCS conceived the study and participated in the study design, collection, management, analysis, and interpretation of data; writing of the report; and the decision to submit the report for publication. LV contributed to patient follow-up examinations and to the data collection. PCN participated in the design and coordination of the study. RCS and LCS critically reviewed the manuscript and approved the final manuscript as submitted. All authors read and approved the final manuscript.

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.

Declarations

Competing interests

The authors declare no competing interests.