Review Reports - Effect of a Novel Handheld Photobiomodulation Therapy Device in the Management of Chemoradiation Therapy-Induced Oral Mucositis in Head and Neck Cancer Patients: A Case Series Study

Round 1

Reviewer 1 Report

Manuscript ID: photonics-2162624

Title: Effect of a Novel Hand-held Low Level Light Therapy Device in the Management of Chemoradiation-Therapy-Induced Oral Mucositis in Head and Neck Cancer Patients: A Case Series Study

I suggest rejecting this article because there were too small a group of patients enrolled in this treatment and because this article has serious flaws.

The research was not conducted correctly especially to analyze the effects of LLLT on the oral microbiome

The methods are not described adequately - for example where are the descriptions of the control groups?

We know nothing about the long-term absence or the presence of expected side effects.

The mechanisms by which LLLT affects cells are controversial.

To consider the results of using an LLLT device and to evaluate its therapeutic effect we need a well-designed large-scale study.

Author Response

Thank you for your important comments and observations. You accurately pointed out the limitations of our study. Although it is a clinical case series, the lack of a control group, the need for a well-designed large-scale study, and the limitations of the oral microbiome analysis are summarized and described at the end of the “Discussion” section. To date, the mechanisms of action of PBMT in OM are not fully understood; Moreover, few studies reported the action of PBMT in CRT-induced OM at the cellular level. But recent studies have demonstrated that PBMT with red and infrared wavelengths normalized epidermal differentiation and maturity, which was impaired in OM lesions by ionizing radiation. Thus, improvement of OM lesions is thought to be achieved by remodeling key epidermal and dermal components^1-6. In addition, we summarized this in the “Introduction” section. We currently do not know about the long-term side effects of this device; however, no serious adverse events have been reported in a number of papers treating cancer therapy-induced OM using similar wavelengths^7,8. Of course, we are aware of the essential need for well-controlled clinical trial studies including long-term follow-up. Nevertheless, this study is meaningful in that it suggests the possibility that a portable hand-held PBMT device that differs from the existing device can be efficiently and conveniently used for cancer therapy-induced OM treatment.
References

Pires Oliveira, D.A.; de Oliveira, R.F.; Zangaro, R.A.; Soares, C.P. Evaluation of low-level laser therapy of osteoblastic cells. Photomed Laser Surg 2008, 26, 401-404, doi:10.1089/pho.2007.2101.
Karu, T.I. Multiple roles of cytochrome c oxidase in mammalian cells under action of red and IR-A radiation. IUBMB Life 2010, 62, 607-610, doi:10.1002/iub.359.
Sommer, A.P. Mitochondrial cytochrome c oxidase is not the primary acceptor for near infrared light-it is mitochondrial bound water: the principles of low-level light therapy. Ann Transl Med 2019, 7, S13, doi:10.21037/atm.2019.01.43.
Tam, S.Y.; Tam, V.C.W.; Ramkumar, S.; Khaw, M.L.; Law, H.K.W.; Lee, S.W.Y. Review on the Cellular Mechanisms of Low-Level Laser Therapy Use in Oncology. Front Oncol 2020, 10, 1255, doi:10.3389/fonc.2020.01255.
Ma, H.; Yang, J.-P.; Tan, R.K.; Lee, H.-W.; Han, S.-K. Effect of Low-Level Laser Therapy on Proliferation and Collagen Synthesis of Human Fibroblasts in Vitro. J Wound Manag Res 2018, 14, 1-6, doi:10.22467/jwmr.2018.00283.
Rupel, K.; Zupin, L.; Colliva, A.; Kamada, A.; Poropat, A.; Ottaviani, G.; Gobbo, M.; Fanfoni, L.; Gratton, R.; Santoro, M.; et al. Photobiomodulation at Multiple Wavelengths Differentially Modulates Oxidative Stress In Vitro and In Vivo. Oxid Med Cell Longev 2018, 2018, 6510159, doi:10.1155/2018/6510159.
De Pauli Paglioni, M.; Araújo, A.L.D.; Arboleda, L.P.A.; Palmier, N.R.; Fonsêca, J.M.; Gomes-Silva, W.; Madrid-Troconis, C.C.; Silveira, F.M.; Martins, M.D.; Faria, K.M.; et al. Tumor safety and side effects of photobiomodulation therapy used for prevention and management of cancer treatment toxicities. A systematic review. Oral Oncol 2019, 93, 21-28, doi:10.1016/j.oraloncology.2019.04.004.
Zecha, J.A.; Raber-Durlacher, J.E.; Nair, R.G.; Epstein, J.B.; Sonis, S.T.; Elad, S.; Hamblin, M.R.; Barasch, A.; Migliorati, C.A.; Milstein, D.M.; et al. Low level laser therapy/photobiomodulation in the management of side effects of chemoradiation therapy in head and neck cancer: part 1: mechanisms of action, dosimetric, and safety considerations. Support Care Cancer 2016, 24, 2781-2792, doi:10.1007/s00520-016-3152-z.

Reviewer 2 Report

The manuscript of In Young Jo et al. is focusing on the application of the novel handheld low-level light therapy device in the therapeutic treatment of chemoradiation-therapy-induced oral mucositis in patients with head and neck cancer. It is an interesting approach which can contribute to commercialization of at-home light therapy devices. The subject matter of the ongoing research is within the scope of the journal Photonics because it concerns the practical application of low-intensity laser radiation for photobiomodulation. The logical structure of the manuscript and the organization of sections and subsections is appropriate. However, there is no Conclusions section. The choice of references does not raise my objections. However, before accepting the manuscript for publication, some additional explanations and corrections are necessary.

Major Comments:

1) There is no information if the used hand-held LLT device is a prototype device constructed by the authors or it is commercially available?

2) There is no explanation for the choice of the used wavelengths of laser radiation. Why did the authors choose these particular wavelengths 670, 780, 830 and 910 nm? As the wavelength increases, the depth of tissue penetration of laser radiation increases, but the manuscript does not provide adequate information on this.

3) All wavelengths were used simultaneously for LLT treatments? The manuscript does not provide precise information on this in the Materials and Methods section. If they were used all of them, then why? Why was it not decided to use one particular wavelength?

4) In Table 2, the radiation power is given, but there is no information on what kind of power? Peak power or average power?

5) As described by the authors ( lines:132-134): “Laser therapy was applied at each point for 20 sec; the protocol was repeated five times at 2-3 minutes intervals, and the total duration was 25-30 minutes”. Why was this particular exposure protocol used? What is its justification? Why did not the authors opt for a longer but single exposure of a particular location?

6) In Table 4, what is column meaning of the data for the No. Does it refer to patient numbers?

7) Why did the authors choose to study the effects of exposure to visible red light and NIR radiation on the microbiome? Was it about the possible stimulation of their growth? This spectral range of radiation will certainly not harm the bacteria themselves.

8) Please explain why “The mechanisms by which LLLT affects cells is controversial,” (line 296).

9) The manuscript lacks a section relating to the conclusion.

Minor comments:

1) The figures and their captions should be on the same page.

2) Some parts of the text are missing spaces between words, e.g. line 201.

Author Response

1. There is no information if the used hand-held LLLT device is a prototype device constructed by the authors or it is commercially available?
Response: This portable PBMT device is a prototype created by the authors and is not yet commercially available. This information has been briefly added to the “Materials and Methods” section.

2. There is no explanation for the choice of the used wavelengths of laser radiation. Why did the authors choose these particular wavelengths 670, 780, 830, and 910nm? As the wavelength increases, the depth of tissue penetration of laser radiation increases, but the manuscript does not provide adequate information on this.

3. All wavelengths were used simultaneously for LLL treatments? The manuscript does not provide precise information on this in the Materials and Methods section. If they were used all of them, then why? Why was it not decided to use one particular wavelength?
Response 2, 3: Thanks to the reviewer for this observation. In fact, in the “Introduction” section (“Discussion” section in the previous submitted version), the actions and characteristics of the four wavelengths we selected were presented and briefly described with references to papers that effectively applied them to the prevention or treatment of OM. However, as you noted, the explanation for this part seemed insufficient, so we added it to the “Discussion” section along with references. In the “Discussion” section, the reason for using all four wavelengths rather than selecting one of them was also briefly explained.
In addition, we have added the process and reason for choosing these specific wavelengths, along with references in the “Materials and Methods” section, as follows: “We selected various wavelengths that were effective for OM by referring to previous studies [34]. Four wavelengths were selected, considering the treatment effect and reproducibility among the candidate wavelengths, and the light source was constructed using these wavelengths.”The PBMT device used in our study uses four wavelengths, which do not come out at the same time, but are output alternately. This was mentioned in the original submitted manuscript in “Material and Methods” section: “This product functions via a 625-Hz pulse operation and performs cross-output of individual laser diodes.” However, we revised the sentence for clarity as below:“This device performs cross-output with a 625-Hz pulse with 200 µs on and 1400 µs off using the four wavelengths mentioned above (Table 2).”

4. In Table 2, the radiation power is given, but there is no information on what kind of power? Peak power or average power
Response: The radiation power presented in Table 2 means average power. We added information in Table 2.

5. As described by the authors (lines:132-134): “Laser therapy was applied at each point for 20 sec; the protocol was repeated five times at 2-3 minutes intervals, and the total duration was 25-30 minutes”. Why was this particular exposure protocol used? What is its justification? Why did not the authors opt for a longer but single exposure of a particular location?
Response: The parameters for using PBMT as a therapeutic modality in OM remain heterogenous and it is still not possible to accurately outline a dosimetry and exposure protocol and a consensus on the wavelengths to be used. Thus, we set the exposure time on the basis of other previous studies with intraoral PBMT in OM patients with head and neck cancers.^1,2In most of the papers that are the basis of the protocol performed PBMT from the beginning of cancer therapy to prevent the occurrence of OM, so there was no need for intervals during PBMT. However, in this study, since the patients with OM of WHO grade 2 or higher were enrolled, it was expected that they would complain of discomfort such as difficulty opening their mouth throughout the 25~30 minutes of treatment, so the intervals were set. In addition, in the study evaluated the therapeutic effect of PBMT on severe OM in childhood cancer, the intervals were set during treatment, so this was referred to and our study was planned. References are as follows. Papers referencing the protocol are attached as references to the laser treatment protocol description in “Materials and Methods” section.
References

(1) Gautam, A.P.; Fernandes, D.J.; Vidyasagar, M.S.; Maiya, A.G.; Guddattu, V. Low level laser therapy against radiation induced oral mucositis in elderly head and neck cancer patients-a randomized placebo controlled trial. J Photochem Photobiol B 2015, 144, 51-56, doi:10.1016/j.jphotobiol.2015.01.011.

(2) Gobbo, M.; Verzegnassi, F.; Ronfani, L.; Zanon, D.; Melchionda, F.; Bagattoni, S.; Majorana, A.; Bardellini, E.; Mura, R.; Piras, A.; et al. Multicenter randomized, double-blind controlled trial to evaluate the efficacy of laser therapy for the treatment of severe oral mucositis induced by chemotherapy in children: laMPO RCT. Pediatr Blood Cancer 2018, 65, e27098, doi:10.1002/pbc.27098.

6. In Table 4, What is column meaning of the data for the No. Does it refer to patient numbers?
Response: In Table 4, No. means the number of patients who clinically showed the corresponding WHO OM grade. We added the information in Table 4.

7. Why did the authors choose to study the effects of exposure to visible red light and NIR radiation on the microbiome? Was it about the possible stimulation of their growth? This spectral range of radiation will certainly not harm the bacteria themselves.
Response: Thank you for your valuable comment and questions. Although there are limitations of numbers and perspectives in the literature, some papers showed that the visible and near-infrared wavelengths of PBMT may affect oral bacterial growth and salivary gland activity by modulating the bacterial cell cycle through interactions on photoacceptors such as cytochrome, flavins, and voltage-dependent calcium channels^1,2. Therefore, we analyzed the patient’s oral microbiome before and after PBMT to determine whether our novel device had any effect on the oral microbiome. The selected wavelengths were wavelengths optimized for OM treatment, and was not determined by focusing on research on changes in the oral microbiome.
References

(1) Amaroli, A.; Ravera, S.; Zekiy, A.; Benedicenti, S.; Pasquale, C. A Narrative Review on Oral and Periodontal Bacteria Microbiota Photobiomodulation, through Visible and Near-Infrared Light: From the Origins to Modern Therapies. Int J Mol Sci 2022, 23, doi:10.3390/ijms23031372.

(2) Basso, F.G.; Oliveira, C.F.; Fontana, A.; Kurachi, C.; Bagnato, V.S.; Spolidório, D.M.; Hebling, J.; de Souza Costa, C.A. In Vitro effect of low-level laser therapy on typical oral microbial biofilms. Braz Dent J 2011, 22, 502-510, doi:10.1590/s0103-64402011000600011.

8. Please explain why “The mechanisms by which LLLT affects cells is controversial.” (line 296).
Response: Thank you for your comment. The sentence may be ambiguous, so we changed the sentence, added references, and rearranged it for better understanding in context.
“To date, however, the mechanisms of action of PBMT in OM are not fully understood; moreover, few studies have reported the action of PBMT in cancer therapy-induced OM at the cellular level.”

9. The manuscript lacks a section relating to the conclusion.
Response: A “Conclusion” section has been added to summarize the contents of this study.

Minor comments
1. The figures and their captions should be on the same page.

2. Some parts of the text are missing spaces between words, e.g. line 201.

Answer: Thank you for your thoughtful review. We have made corrections, as you suggested.

Reviewer 3 Report

The manuscript entitled: “Effect of a Novel Hand-held Low Level Light Therapy Device in the Managemen of Chemoradiation-Therapy-Induced Oral Mucositis in Head and Neck Cancer Patients: A Case Series Study” by In Young Jo, et al, presents a novel laser therapy using a low level light therapy device. This new therapy allows for reducing significantly the oral mucositis grade, without any type of side effect, avoiding any detrimental effect on oral microbiome and improving the patients’ helath-related quaility of life. The topic is timely, the work is sound and the results are remarkable. However, the introduction should be more extensive in order to understand better the work done previously related to this therapy. This section should be checked thoroughly. Overall, the work is certainly publishable and contributes to research area of laser therapy for wound healing. I recommend this manuscript for publication in the special Issue "Light as a Cure: Photobiomodulation, from the Cell to the Clinical Application” of Photonics after minor revisions as follow.

1) The introduction of the report is adequate, helps to go deep into the issue reported herein and the paragraphs are linked each other resulting in a very clear introduction. However, I miss in some cases more specific reference about the work done previously and related to this therapy.

2) Related to the first comment, I think that much of the information about the treatment given in the Discussion section (section 4) must be included in the Introduction section (section 1). The information given from line 287 to 312 is not part of the discussion about the results obtained in the experiment. The information given in the aforementioned lines helps readers to understand better the previous works done in this field, so it must be included in the Introduction (and removed from Discussion). The same thing occurs with the information given from line 333 to 363. This information is part of the introduction; it is not a discussion about the results obtained in the experiment. Please, shift it from the Discussion to the Introduction.

In conclusion, the introduction should be rewritten taking into account the comments done before.

3) Just as a curiosity, how much does the device shown in Figure 1 cost? May be you can include this information in the text.

4) The treatment protocol mentions that laser therapy was administrated through a non-contact modality. If there is not contact, which is the correct distance between the laser and the oral cavity with OM lesions? Is this issue important in order to reach good results in LLLT?

5) In Table 7 there is no explanation about the meaning of ETC (<1%). It should be mentioned in the key of Table 7 or in the text previously.

6) I miss a section with the conclusions deduced from the experiment. The main conclusions should be mentioned in a last new section highlightening the major achievement obtained in this novelty therapy.

Author Response

The introduction of the report is adequate, helps to go deep into the issue reported herein and the paragraphs are linked each other resulting in a very clear introduction. However, I miss in some cases more specific reference about the work done previously and related to this therapy.
Related to the first comment, I think that much of the information about the treatment given in the Discussion section (section 4) must be included in the Introduction section (section 1). The information given from line 287 to 312 is not part of the discussion about the results obtained in the experiment. The information given in the aforementioned lines helps readers to understand better the previous works done in this field, so it must be included in the Introduction (and removed from Discussion). The same thing occurs with the information given from line 333 to 363. This information is part of the introduction; it is not a discussion about the results obtained in the experiment. Please, shift it from the Discussion to the Introduction.
In conclusion, the introduction should be rewritten taking into account the comments done before.
Response to 1, 2: Thank you very much for your careful review of my manuscript and for your feedback. As you suggested, the background information that is not related to present study was moved from the Discussion section to the Introduction section, redundant information was deleted, and the context was organized for better understand.
Just as a curiosity, how much does the device shown in Figure 1 cost? May be you can include this information in the text.
Response: This portable PBMT device is a prototype developed by the authors and is not yet commercially available. The price has not been set because it is not yet on sale, but it is expected to be USD 2,000-3,000, and will be upgraded and sold with more optimized equipment. This part has been briefly added to the “Materials and Methods” section.
The treatment protocol mentions that laser therapy was administered through a non-contact modality. If there is not contact, which is the correct distance between the laser and the oral cavity with OM lesions? Is this issue important in order to reach good results in LLLT?
Response: This device was used in a non-contact manner in which the laser irradiation part was covered with a disposable vinyl cover to prevent possible side effects such as direct tissue damage, and the distance from the oral mucosa was approximately 0.2-0.5 cm. Although skilled operators performed the treatment, it cannot be concluded that the distance was completely constant, and this could affect the amount of energy reaching the tissue. These limitations were briefly described in the “Discussion” section.
Of course, the longer the distance between the laser and the oral cavity, the smaller the energy reaching the tissue. However, judging from the treatment mechanism of PBMT, stronger energy does not always produce better treatment effects; and unlike coherent lasers, most PBMTs use non-contact methods. However, through further research using this device, an optimized protocol including energy, irradiation time, and distance should be established. We have modified and described this in the “Discussion” section.
In Table 7, there is no explanation about the meaning of ETC (<1%). It should be mentioned in the key of Table 7 or in the text previously. Response: Thank you for your meticulous observation. Taxa with a relative composition ratio of less than 1% were represented by the abbreviation ETC. We apologize for not providing an additional explanation; and as suggested by the reviewer, we have added a brief explanation of ETC below Table 7.
I miss a section with the conclusions deduced from the experiment. The main conclusions should be mentioned in a last new section highlightening the major achievement obtained in this novelty therapy.
Response: Thank you for valuable comment. The main outcomes of the application of the new portable PBMT device in the management of CRT-induced OM are summarized and added to the “Conclusion” section.

Round 2

Reviewer 1 Report

I suggest rejecting this article because this article has serious flaws for example the lack of a control group.
The reports indicate that cancer can be related to the disorder of the microbiome which is targeted by current medical treatments
The research in the revised version was not conducted correctly especially to analyze the effects of LLLT on the oral microbiome. Additionally, we know nothing about the long-term absence or the presence of expected side effects of a novel hand-held low-level light therapy (LLLT) device, especially in head and neck cancer patients during their complexity of treatment.
We need research on whether LLLT can be connected to the growth and metastasis of tumors whether LLLT maybe is safe for cancer patients or whether LLLT can delay the growth and metastasis of tumors.

Author Response

Thank you for your meaningful comments and observations. You again pinpointed the limitations of our study accurately. As we answered in the 1^st revision, there is an explicit limitation in that this study could not set up a control group, and there are limitations in oral microbiome analysis, so additional research in being planned. This is summarized and explained at the end of the “Discussion” section. We also understand the need for more extended investigation periods to identify long-term side effects or the impact of our novel device on patients’ cancer progression. There is no defined treatment protocol for head and neck cancer patients on photobiomodulation. Still, the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) suggested photobiomodulation for the prevention and treatment of oral mucositis in head and neck cancer patients undergoing radiation therapy. And many studies have already shown positive results on the effect of photobiomodulation on these patients. Among them, in Brandao et al.¹, when photobiomodulation was used for oral mucositis in patients with locally advanced oral squamous cell carcinoma, there was no adverse effect on the treatment outcomes of the primary site or recurrence of new tumors during the 5-year follow-up durations. In addition, in Antunes et al²., it was revealed that photobiomodulation improved the overall survival rate in head and neck cancer patients receiving chemoradiation therapy with photobiomodulation in a randomized phase 3 trial during long-term survival follow-up. However, some in vitro studies have reported differing results on the effect of photobiomodulation on tumor cells; we agree that it should be used more cautiously until further studies confirm the safety of photobiomodulation in cancer patients. However, studies to date have not reported any results that affect the progression of cancer cells, except when excessive amounts of energy are directly applied to cancer cells.^3-5 In addition, in the case of the subjects of this study, this treatment was performed except for the primary cancer site, with no current cancer tissue in the oral cavity, and this was the same in other existing papers. However, we strongly agree with your opinions regarding the limitations of this study and the need for additional research, and we plan to conduct further research based on this study.

References.

Thais Bianca Brandao, Karina Morais-Faria, Ana Carolina Prado Ribeiro, et al. Locally advanced oral squamous cell carcinoma patients treated with photobiomodulation for prevention of oral mucositis: retrospective outcomes and safety analyses. Support Care Center. 2018;26(7):2417-2423.
Heliton S Antunes, Daniel Herchenhorn, Isabele A Small, et al. Long-term survival of a randomized phase III trial of head and neck cancer patients receiving concurrent chemoradiation therapy with or without low-level laser therapy (LLLT) to prevent oral mucositis. Oral Oncol 2017;71:11-15.
Kreisler M, Christoffers AM, Al Haj H, et al. Low level 809nm diode laser-induced in vitro stimulation of the proliferation of human gingival fibroblasts. Lasers Surg Med 30(5):365-369.
De Castro JL, Pinheiro AL, Werneck CE, Soares CP, et al. The effect of laser therapy on the proliferation of oral KB carcinoma cells: an in vitro study. Photomed Laser Surg 23(6):586-589.
Volker Hans Schartinger, Oliver Galvan, Herbert Riechelmann, et al. Different responses of fibroblasts, non-neoplastic epithelial cells, and oral carcinoma cells to low-level laser therapy. Support Care Cancer 2012;20(3):523-529.

Reviewer 2 Report

Thank you for the clarifications provided and the corrections made to the manuscript. In my opinion, however, there are still some issues that should be clarified before publication.

1) Since the photobiomodulation system was developed by the authors, it is a great pity that the authors did not choose to submit a manuscript to the journal Photonics describing the device in detail, the operating characteristics, and test studies on the stability of the radiation exposure conditions, instead focusing only on the practical application of the device. Combining these two aspects would enhance the scientific quality of this manuscript.

2) The description of the laser system for photobiomodulation itself is very cursory and is limited only to the specification of the radiation sources used and the description in the caption of Fig.1. In my opinion, the authors should add a separate subsection in the Materials and methods section with a more detailed description of the designed system for laser irradiation. How is the illuminating probe constructed, does it use lenses, diffusers? What is the light beam generated (divergent, convergent, collimated)? How is a constant beam diameter obtained on the surface of the illuminated tissue under constant exposure and photobiomodulation conditions? The use of a disposable vinyl cover in laser irradiation part achieves what beam diameter at the tissue surface? What is the change in beam diameter at a distance of 0.2-0.5 cm from the illuminating probe. These questions have not clarified.

3) Why were laser radiation sources of different average powers used? Was this due to the availability of commercial light sources for a given wavelength, or was it related to previous studies?

4) What were the half-widths of the emission spectra of the light sources used (please add this information to Table 2).

3) Please review and correct all formatting errors, for example, page 6 line 12: “0.2=0.5 cm”

For future reference, I encourage the authors to also provide the final version of the manuscript (without tracking changes) to reviewers after the corrections have been made, which greatly improves the preparation of the final review report.

Author Response

Thank you for your valuable comments. We upload response as a Word file.

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

Comments and suggestions for Authors

Sorry, but I recommended rejecting your manuscript. Sorry, but in my opinion, your research was executed in an invalid manner.

Reviewer 2 Report

Thank you for your answers and the authors' clarifications. Admittedly, the number of patients studied is small, but as the authors themselves state in the title, this is a preliminary study, so the results published there seem sufficient to me. However, further studies should be carried out to examine a larger number of patients and to determine the long-term response to photobiomodulation in order to definitively confirm its efficacy. In my opinion, the article is suitable for publication, but I would suggest the authors to better distribute the table. Tables spread over two pages are not very readable for the audience.